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Old Jun 03, 2011, 04:16 PM
OlliW
Joined Sep 2009
1,454 Posts
Build Log
GA250 Coax Gyromixer: The Ultimative Boardless Brushless Conversion?

Hey coax enthusiasts,

to start with, I know, the title is a bit provocative... there is certainly nothing such as "ultimative" in this hobby...

Anyhow, I am kind of active in this forum since some time but have never ever actually started a thread, so I thought I could open one and share my latest project with you. The project I am going to describe is in some way the most simple approach to a BLBL conversion but at the same time also the most "stupiest"... I am sure you will have your own opinion on this.

Current state of affairs (Oct. 23 2011)
This project evolved since the first posting quite a bit, in particular Tommy@LA from RCline Forum successfully build a GA250 gyromixer Big Lama BLBL, and his problems with the gyromixer helped me a lot to improve it and solve the issues (many thanks to him). As with Version 0.21 I think the project is kind of mature and I hence consider it now as stable. I have updated all the sections below accordingly.

I have also added a full list of the hardware and software which is needed for completing the hardware modding of the GA250 and running it.

I understand that for many of you the hardware modifications and burning the bootloader(s) may be scaring off. So, if that's the case but you would otherwise have liked to give this project a try I do offer this: If you send me all required hardware together with a return ticket, I will do the modding and burning and send it back to you (all for free).

(the statement "all required hardware together with a return ticket" should mean that I get everything needed so that I do not have any financial cost including the shipping and the "only" thing I have to do is to do the work, I don't have the financial resources to stockpile things )

Terms of usage
The software/firmware is not free. You may use it gratis and freely for private purposes. However, you may not use the work in full or in parts in any manner that is intended for or directed toward commercial advantage or private monetary compensation without explicit agreement by the author.

About this project
As you know, in a BLBL conversion all electronics except of maybe the reciever is removed, and replaced by devices which provide the five functions reciever, gyro, mixer, BESCs, and BEC. From these five functions the two most critical ones are the gyro and mixer. The choice of the BESCs is mainly dependent on the power requirements/desirements, but otherwise rarely a problem since essentially all BESCs of today will work fine. The BEC is usually integrated in the BESCs, and no concern either. And the choice of a reciever has often been made way before venturing into BLBL. In contrast, the choice of the gyro and mixer is critical. This is seldomly because of perfomance issues, but because of communication issues: the mixer has to deal with an asynchrounous inflow of PPM signals from the reciever and gyro, and it's not garantueed that any mixer will work with any reciever and gyro combination. In fact, reviewing the various brushless conversion approaches presented in the past, one may summarize them as the never ending story of how to deal with the gyro and mixer functionalities in the BL game...

I will here describe how to modify the hard- and software of the ASSAN GA250 gyro (a MEMS gyro for 10$ at HK) such as to work as both gyro AND mixer - I call this a coax gyromixer. As a result, it becomes the only other electronic piece required for a full BLBL conversion besides the reciever and BESCs. As you will see, the hardware is the simple part in the game since not much has actually to be done here, just some simple solder work. However, though the GA250 provides a convenient hardware platform, its software has to be redone to get it to work as a gyromixer. Since the GA250 does not come with any means to adjust parameters, such as gain or prop, one has also to implement a means to "program" it. This could be done via the usual transmitter-stick-up-down-procedures, which I however don't like much, in particular if many parameters are provided. I hence decided to realize the parameter setting via a programming box which can be connected to the GA250 gyromixer, and I found the Robbe Programming Box V2 to be an excellent hardware platform for that matter. In the meantime I have also developed a Windows GUI which allows setting the parameters of the GA250 gyromixer from a PC. I called it AvrConfig. Hence, these two alternatives exist now; the PC option is certainly cheaper while the programming box option may be more convennient (but is not easily found in the US).

So, this project, the GA250 coax gyromixer project, consists of four things, the hardware modifications to the GA250 gyro, the firmware for the GA250, the AvrConfig PC program, and the firmware for the Robbe Programming Box.

During development of such a project it can hardly be avoided that the micro controller(s) need to be reflashed often, it is hence quite convenient to use a bootloader. I am using the bootloader by Haagen published in a German forum, http://www.mikrocontroller.net/topic/95839#new. It is powerfull yet compact. Thanks to Haagen for this excellent piece of work!

I will start with chating a bit about the background of this project. I will then describe the hardware of the GA250 gyro and Robbe Programming Box, will then present the remodelling of the GA250 gyro, and spend some words on the firmware for it. If you are not afraid of German, or reading a google English translation, you may follow the project also here: http://www.olliw.eu/2011/ga250-fpkoax-gyro-mischer/
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Old Jun 03, 2011, 04:16 PM
OlliW
Joined Sep 2009
1,454 Posts
Background

Background:
The whole thing started about 1 1/2 years ago, then I decided to also attempt a brushless conversion of my esky lama V4. Hence I bought one of these "plug-and-play" kits, which consist of the motors, the BESCs, and two converters. The conversion worked... but barely so... I didn't liked the performance at all. The tail was extremely waggy, and I found this inacceptable. The obvious next step would have been to go BLBL, but somehow I didn't liked that either. Instead I realized that the ESKy 4in1 can be remodelled such, by removing the original processor and replacing it by an Atmel Attiny 861, that I can program it with all functions I wanted to. This resulted in what I called the 4-1+2in1 project (4in1 with the BEC removed but a lipo saver and a light controller added). The first working version performed quite nicely, and I liked the lipo saver and the switchable lights (canopy lights, Landing light, spot light). I worked on putting this hardware-wise onto more "solid" grounds, but despite several attempts this never actually got to anything final. About a year ago, I started with CP helicopters, and as a result I got in touch with gyro's such as the HK401B or KDS800. Of course, I peeked inside them and realized that they provide all the hardware components needed to implement both the gyro and mixer function, and moreover the hardware was essentially identical to what I used already in the 4-1+2in1 project... and the coax gyromixer project was born. I developped this into a working version, but did not further pursue this path, since the 4-1+2in1 approach looked more appealing to me, on which I focused in the recent time. I fooled around a bit with the LPX brand of MEMS gyro from ST, but found them to be too vibration sensitive, and the latest attempt was hence based again on the Murata piezo gyro.

However, the appearance of the GA250 has quite changed the game. It made me to stop my latest attempt in the 4-1+2in1 project, since it made me realize that the time of piezo-gyro based projects has passed (I do not have - yet - the skills to solder ICs such as the new Invensense gyros), and on the other hand it pushed the coax gyromixer project back into the limelight, because of the coolness factor of a MEMS gyro and the cheapness of the GA250. The result you find below.
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Old Jun 03, 2011, 04:17 PM
OlliW
Joined Sep 2009
1,454 Posts
GA250 Hardware

GA250 Hardware:
In the following pictures are shown the top and bottom sides of the print board contained in the GA250 together with my labeling of the components, the electric circuit diagram, and the original fuse settings:


http://www.olliw.eu/uploads/gyro-GA250-withanno-wp.jpg


http://www.olliw.eu/uploads/gyro-GA250-circuit.png

Fuse Settings: http://www.olliw.eu/uploads/gyro-GA2...ogfuses-wp.jpg

The hardware consists of an Atmel Atmega8 micro controller (the label has been made irrecognizable, but according to avrdude the chip ID is 0x1e9307) run by a 8 MHz ceramic oscillator. The gyro sensor is the Invensense ISZ-650 (the label has also been made irrecognizable, it also could be the ISZ-500, but this appears unlikely). The GA250 offers a red and a blue led for signaling. Also, it offers a quite elaborate voltage source and reference voltage circuitry, and the print board (4 layer!) and fabrictaion (soldering!) appears to be of high quality. I would not have expected to see such a high quality both as regards the electronic scheme and fabrication in such a low-cost product (I hope that this is not going to change in time). Congrats ASSAN. The most beautiful thing, however, is that the ISP pins, which allow programming the micro controller, are easily available via soldering pads. Besides the fact that it offers a high quality MEMS gyro sensor, this point makes the GA250 an ideal platform for this project. Hardware-wise it can't be simpler.

Atmega8 datasheet: http://www.atmel.com/dyn/products/pr...0&part_id=2004
ISZ-650 datasheet: http://invensense.com/mems/catalog.html

The ports of the Atmega8 are connected as follows:
PB0 / ICP: input signal 1 from reciever (rudder input in the gyromixer)
PD2 / INT0: input signal 2 from reciever (throttle input in the gyromixer)
PB2 / OC1B: output signal 1 (PPM output signal for motor B in the gyromixer)
PC0 / ADC0: PTATS signal from ISZ-650 gyro sensor (this reads the temperature, not used in the gyromixer)
if one removes R14 this port may also be used as a further analog input, e.g. for a lipo saver
PC1 / ADC1: Zx4.5 out signal from ISZ-650 gyro sensor (+-440°/s -> +-1V gyro signal)
PB4 / MISO: AZ pin of the ISZ-650 gyro sensor (allows to zero the gyro signal)
PD3: red LED
PD4: blue LED

Via the ISP pads additionally the following ports are easily available:
PB3 / MOSI: general port (PPM output signal for motor A in the gyromixer)
PB5 / SCK: general port (connection to the programming box and bootloader in the gyromixer)

Two further ports are available through careful soldering (and removing of R11):
PD5: (not used yet in the gyromixer)
PD0/PD1: these two ports are connected (not used yet in the gyromixer)

In order to use the GA250 for our purposes, in principle only two cables need to be soldered to those two pads, which are connected to ports PB3 and PB5. These together with the other cables will provide the two PPM inputs for rudder and throttle, the two PPM outputs for the BESCs of motor A and B, and an additional connector for attaching the programer box.
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Old Jun 03, 2011, 04:17 PM
OlliW
Joined Sep 2009
1,454 Posts
Robbe Programmer V2 No. 8642 Hardware

Robbe Programmer V2 No. 8642 Hardware:
In the following pictures are shown the top and bottom sides of the print board and a hand drawing of the electronic scheme, the electric circuit diagram, and the original fuse settings:


http://www.olliw.eu/uploads/robbe-pr...2no8642-wp.jpg


http://www.olliw.eu/uploads/robbe-pr...circuit-wp.jpg

Fuse setting: http://www.olliw.eu/uploads/robbe-pr...2-fuses-wp.jpg

The hardware consists of an Atmel Atmega88 micro controller run by a 8 MHz ceramic oscillator, a 2x16 tiny LCD display (no backlight), four keys, a beeper, and a servo connector. Again, besides offering all the hardware required for a "cool" programming box the most beautiful thing is that the ISP pins are easily available via soldering pads, which makes the Robbe Box an ideal platform for our (and many other :-)) purposes.

Atmega88 datasheet: http://www.atmel.com/dyn/products/pr...0&part_id=3302

The ports of the Atmega88 are connected as follows:
PB3: E line of the LCD display
PB4: R/W line of the LCD display
PB5: RS line of the LCD display
PC0-PC4: DB4 to DB7 lines of the LCD display
PB5 / OC1B: beeper (high = off!)
PD6: down arrow key (most left key)
PD5: inc + key (middle left key)
PD4: dec - key (middle right key)
PD7: up arrow key (most right key)
PD0 / RXD & PD1 / TXD: connected via a resistor network to the servo connector, allows for a half-duplex serial 1-wire communication

In order to use this box, no hardware changes are required!

EDIT(2. July 2011): The Robbe Box may also come with an Atmega88PA (signature 0x1e930f) instead of the Atmega88. Otherwise, however, the circuit and fuse settings are exactly identical as shown in the above.
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Old Jun 03, 2011, 04:18 PM
OlliW
Joined Sep 2009
1,454 Posts
Remodelling of the GA250 gyro

Remodelling of the GA250 Gyro:

Update Oct. 23 2011: the photos below show the result of my first converson of a GA250 to a GA250 Gyromixer. In the meantime I do some things in a somewhat better way. A gallery of photos which presents the current remodeling of the hardware in much more detail can be found here: http://www.olliw.eu/2011/ga250-fpkoa...cher/#21072011

The first step consists of soldering the cables to the ISP pads and flash the Atmega8 with Haagens bootloader. This looked as follows:


http://www.olliw.eu/uploads/gyro-ga250-mod-isp-wp.jpg

Then these cables can permanently be removed, and two cables soldered to the pads which are connected to ports PB3 and PB5. In principle this would be it, but I did a bit more soldering to end up with a nice, fully wired device:


http://www.olliw.eu/uploads/gyro-ga2...umbau01-wp.jpg


http://www.olliw.eu/uploads/gyro-ga2...umbau02-wp.jpg


http://www.olliw.eu/uploads/gyro-ga2...umbau03-wp.jpg


http://www.olliw.eu/uploads/gyro-ga2...umbau04-wp.jpg

That's it for the hardware
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Old Jun 03, 2011, 04:19 PM
OlliW
Joined Sep 2009
1,454 Posts
Firmware for the Programming Box and the AvrCongif PC Program

Firmware for the Programming Box:
As with the GA250 the first thing to do is to solder cables to the ISP pads and burn the Atmega88 or Atmega88PA (which depends on your Robbe Box) with Haagens bootloader. Here I used a modified version of the bootloader, which requires the most left key to be pressed upon startup for the bootloader to become active. This was necessary to avoid potential communication conflicts on the one-wire port. After that the ISP cables can permanently be removed and the box closed, "for ever".

Then the firmware can be flashed into the programming box using Haagen's AVRootLoader Windows program. A serial or usb port is needed on the computer and an approrpiate adapter needs to be build (which is however simple to do) to connect the programming box to the PC.

A link to the latest firmware for the programming box I will provide below.

Functions of the Programming Box
The programming box is connected to the gyromixer via a standard servo extension cable to the programming connector atthe gyromixer, which is the YELLOW marked one. ATTENTION: please ensue that the servo extension cable is correctly plugged into the programming box (the black/brown ground cable should be at the top, and the white/yellow/orange/red signal cable at the bottom). Depending on the current state of the gyromixer (see next post), a connection is then established, which will be indictaed on the gyromixer by a blue LED going on and on the programming box by the display changing from "not connected" to showing the first menu item.

One may browse the parameters using the up and down keys to the most rright and left. The paramter setting may be changed using the + and - keys (also labelled Inc and Dec) in the middle of the key field.

IMPORTANTLY: Any change to the parameter becomes effectivel immediately. That is, if one disconnects the programming box and starts flying, the newly set parameters wil be used. This is most convennient as the heli does not have to be switched on and off for every parameter changes. HOWEVER, the parameter changes will be lost if the gyromixer is switched off, and the "old" parameters would be used the next time, whichis convennient of one doesn't like the parameter setting.

In order to store the current parameters PERMANENTLY one has to browse to the last menu item, switch to yes by pressing the + button, and initiate the permanet store by holding down the + key for about 2 seconds.

Some words on what happens internally.
The firmware for the programming box consists in fact of two parts, which have to work hand-in-hand, namely the code which is to be flashed into the uC of the programming box, and of course the code which has to be integrated into the GA250 software as the counter-part. The development of these software was in fact (so far) the most difficult part in the project, because of two reasons:

(A) I didn't wanted to have to update the software for the programmer box whenever I would change the parameters for the GA250 gyromixer... So, the parameters, their values, etc., i.e., the menu of the programming box has to be stored somehow in the GA250 itself. Since, however, menus do quickly consume quite a lot of the precious memory space this has to be done in some clever, memory friendly way.

(B) The communication between the box and gyromixer should be one wire, which in principle is simple. However, unfortunately, the ports easily available via the soldering pads in the GA250 do not provide an interrupt, hence one has to use a software UART with polling, but polling means that any interference by interrupts has to be avoided, which in turn means that during this time period all actions basically have to be disabled. In short, having to use a polling software UART requires some quite careful considerations as regards the communication protocol and timing.

Anyhow, after some efforts I found a reasonable solution. It comes at some cost, however, namely the minimal frame length for the PPM output signals to the motors is limited to 4 ms... Clearly, 3 ms or even 2 ms would be cool, but considering the limitations set by the mechanics of the coax heli itself a frame rate of 4 ms, which corresponds to 250 Hz update frequency, is way sufficient.


AvrConfig Windows PC Program
As an alternative to the programming box, a Windows PC program is available which allows to set the parameters via a GUI. A screen shot is attached below.

However, in contrast to the programming box it doesn't allow a "live" changing of the parameters. That is, the gyromixer has first to be connected to the computer, then the "Connect" button needs to be clickedm, and then the gyromixer needs to be switched on. Now the paramters can be read from the gyromixer, changed, and written back into the gyromixer. During all this the gyromixer is not functional as the firmware in it is actually not excecuted.

For the connection to the gyro mixer a computer with a serial or usb port is needed. If the usb port is to be used, which I consider the standard way of doing things and which I will describe only here, one needs a USB-TTL adapter together with a connector-button-wire-assembly which is described below (I call it the USB-Programming Adapter), and the appropriate drivers such that the usb-ttl adapter is recognized as a virtual COM port by Windows.

PS: I am not a good Windows GUI programmer, so I am not sure how well AvrConfig will do on different environments, I have tested it myself on a couple of Windows XP computers, where it worked, but this doesn't mean a lot. The key problem is the COM port handling (enumerating, timeout settings).
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Old Jun 03, 2011, 04:19 PM
OlliW
Joined Sep 2009
1,454 Posts
Firmware for the GA250 gyromixer

Firmware for the GA250 gyromixer:
The firmware is currently in Version 0.22. The most important advancement as compared to the first version(s) posted here is that heading hold is now implemented and fully operational, and failsafe is considered. Also, some behavior which could confuse the user was improved.

A link to the latest firmware is provided below.

The main function, the gyro, is implemented as a simple PI controller. I fooled around with a PID controller with real D term and setpoint weighting, but didn't found this to be of any advantage, in the contrary. So, I sticked to a PI controller. The second function, the mixer, is a piece of cake to implement.

Besides these two native functions, which give rise to the parameters gain and prop as they are also usually available via potis in the standard coax electronics, I implemented quite a number of additional features which allow to fine-tune the behavior of the coax, such as expo for rudder, or various parameters to affect the throttle curve. So, the number of parameters may look scaring but most are actually not mandatory for a basic functioning, but can signficantly improve the "feel" of how the coax flies.

Parameters in the GA250 Gyromixer
Gyro Mode [off,rate,heading hold]
rate and heading hold shoudl be obvious
off means that the gyro is completely inoperative, which is an intersting experience, but is actually implemented to facilitate a test, which I would ask experienced pilots to do
Rate Gain [0.00 ... 2.50]
gain when gyro is operated in rate mode
PID Gain [0.00 ... 2.50]
gain when gyro is operated in heading hold mode
PID I [0.000 ... 0.100]
this is simply spoken the heading hold capability (and hence only effective in heading hold mode)
The larger this value, the more serious is the gyro about holding the heading, but by increasing it usually also gain has to be reduced to avoid tail wagging. Hence a compromise between large gain and large I has to be found. A good approach is to first determine the gain setting when operated in rate mode, and when to slowly increase I from zero in heading hold mode.
Prop [-100 ... 100]
should be obvious, corresponds to the prop dial on the usualy 3in1 or 4in1 koax units
Revo [-100 ... 100]
allows for a pitch dependent compensation of the torque excerted by the two rotor. This can significantly help the gyro to do its job upon strong "pitch pumps". Technically, revo changes the slopes of the throttle curves of motor A and B in comparison to each other.
Rudd Rate [0.0 ... 3.0]
sets the maximally possible pirouette rate, 1.0 corresponds to about 1 turn per second
Due to the limitations of the ISZ650 gyro sensor used in the GA250 device, a pirouette rate larger than ca. 1.3 leads to uncontrolled pirouettes at large rudder signals, this can be impressive and fun though. Increase this value ONLY slowly step by step by 0.1 ticks.
Rudd Expo [0.00 ... 1.00]
expo setting for rudder
This allows to have more sensitivity for rudder control near zero rudder. A value of 0.00 means no sensitivity enhancement (expo off), a value of 1.00 corresponds to a completly flat response near zero rudder.
Thro Expo [0.00 ... 1.00]
expo setting for thror
This allows to have more sensitivity for thro control near the thro level determined by Thro Hover. A value of 0.00 means no sensitivity enhancement (expo off), a value of 1.00 corresponds to a completly flat response near the Thro Hover point.
Thro Hover [25% ... 75%]
refence for the Revo and Thro Expo functions
Thro Min [0% ... 35%]
lower limit to the PPM signals send to the BESCs of the motors
This allows to fine tune the reponse of the koax upon thro.
Thro Max [65% ... 100%]
upper limit to the PPM signals send to the BESCs of the motors
This allows to fine tune the reponse of the koax upon thro.
Frame Length [4 ms ... 22 ms in steps of 2 ms]
frame length of the PPM signals for the BESCs for the motors
In principle the shorter the frame rate the better, however not all BESCs may work with to short frame lengths.

Besides these, additional parameters are available, which are however only for "experts". These are:
Low Pass Time [0 ... 10]
Low Pass Average [1 ... 8]
Cntrl Limit [0 ... 500]
Dead Band [0 ... 30]
Rudd Sense [0.00 ... 1.00]
Mot Min Value [us]
Mot Max Value [us]
Thro Min Value [us]
Thro Max Value [us]

Functions of the GA250 Gyromixer
The behavior of the gyromixer and its interaction with the programming box is described. The gyromixer has a red LED and a blue LED, which are of course used to signal in which state the gyromixer currently is, on which its behavior of course depends. Unfortunately the red LED is not well seen if the blue is on, look carefully, it's easy to get confused here. The meaning of the LEDS is that:

The blue LED is ON whenever a connection to the programming box is established, and OFF if not (whith one lttle exception, see below).

The red LED tells you about the current STATE of the device. The gyromixer can be in any of FIVE different states:

(A0) Initialization and startup
This is the state after having switched on the gyromixer. The gyromixer first waits for a valid signal to come in from the reciever. The red LED is blinking very fast.

(A1) Rx signal recieved
Once a valid rx signal has been detected the gyromixer checks for the position of the Thro stick. The red LED is blinking fast. The gyromixer will wait as long as one the following positions have be detected:
Thro fully down (Thro low):
If the gyromixer detects thro down at startup it moves on and enters the Thro low state (C). Once it has entered this state the gyromixer can only be in either state (C) or (D).
Thro fully up (Thro high):
If the gyromixer detects thro up at startup it enters the Thro range programming state (B).

(B) Thro range programming mode
That's essentially exactly what is known for the BESCs. That is, as next step one is expected to pull the Thro stick fully down, which makes the gyromixer to store the Thro up and down values of the transmitter/reciever into memory, i.e., the gyromixer is learned as for BESCs. In that mode the red LED blinks slowly. Once Thro fully down is detected the red and blue LEDs start blinking alternatively, and the only way to get out of that mode is to switch off the gyromixer.

IMPORTANTLY, during states (A1) and (B) the Thro signal as it is recieved from rx is passed through unchanged to the two motor outputs of the gyromixer. That is, by having Thro up at startup and pulling it then down, it is possible to simultaneously learn also BOTH BESCs! In these states the gyromixer behaves as if it were a "piece of wire" as regards the PPM signals to the motor BESCs.

(C) Thro low mode:
This mode is entered whenever the gyromixer detects that the Thro stick is low for longer than ca. 4 seconds. The red LED will be on. In this mode a signal is output to the motor outputs, but the rudd, gyro, and mixer functions are off for saftey reasons.

(D) Flight mode:
If the Thro is moved up a tiny bit (4% of the full range if the gyromixer was learned), the gyromixer enters the Flight mode and the red LED goes off. In this mode the motor BESCs get their PPM signals and the gyromixer does what you expect it to do. During the transition from state (C) to state (D) the gyromixer will be recalibrated, i.e., the gyrosensor signal will be reset to zero. Hence, one actually doesn't have to keep the coax standing still after switched on, since the crucial calibration steps will be done ONLY very shortly (10 ms) before the Flight mode is entered.

Failsafe:
If a loss of a valid signal from the reciever is detected, the gyromixer enters the failsafe condition. This is not actually a separate state but may occur during any of the above states. During Failsafe, the red LED blinks very fast. In states (A) and (B), a failsafe will "reset" the gyromixer and it will start from the very beginning, i.e., state (A0). In state (C) a failsafe doesn't harm much and hence not much is happening. However, as a saftey feature the gyromixer will require that Thro is low for few seconds before it accepts any further thro commands. In state (D) the motor signals are slowly reduced to minimum for saftey. However, if within this period a signal is comming in again, the motor signals will go back to what they are supposed to be.

Interaction with the programming box
IMPORTANTLY, a connection to the Robbe Box is ONLY possible if the gyromixer is in STATE (A) or (B) or (C), but not in state (D). (I figured it doesn't make much sense to change parameters during flight... ).

However, a failsafe doesn't interfer with the connection. Hence, if one is in state (C) one may switch off the transmitter if one wants for saftey reasons before one connects the programming box to the gyromixer. After having finsihed the programming bussines one may switch on the transmitter again, but the gyromixer will wait for thro is low before it allows to continue.

As stated before, the blue LED will go on if a connection is established, which is also indicated on the display of the programming box.
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Old Jun 03, 2011, 04:20 PM
OlliW
Joined Sep 2009
1,454 Posts
Demonstrating the claims

"Demonstrating the Claims":
So much to the claims. Here now some pictures/videos to demonstrate what has been, and what has not yet been achieved:

picture of BLBL lama V4 coax used for the developments and tests:

http://www.olliw.eu/uploads/gyro-ga2...umbau05-wp.jpg

Here I wanted now to provide two videos, but I couldn't figure out of how to embeed in a similar way as the pictures or as it's seen in so many posts (somehow a usueful help does not seem to exist)(maybe some has an advice for me). So, sorry, I can just direct you to the following sites

video of the basic features and functions of the GA250 gyromixer in version 0.10:
http://www.olliw.eu/2011/ga250-fpkoa...cher/#25052011
[or for download http://www.olliw.eu/uploads/coax-gyr...etup-en-wp.flv]

flight video:
http://www.olliw.eu/2011/ga250-fpkoa...cher/#02062011
[or for download http://www.olliw.eu/uploads/coax-gyr...light04-wp.flv]

EDIT: A careful observer will realize the points which could still be improved. The tail is slightly drifting. I don't think that this is gyro drift, I mean, it's a MEMS gyro now. I rather think that it's due to the trivial effect that with lowering battery voltage during flight the prop doesn't stay constant. I hope that this will be solved by implementing a heading-hold gyro. Also, the tail yaws a bit upon sudden pitch pulses (what's the correct English word for that!?). I observed that, and tried to understand the origing, for quite a while now, but I still don't have a clue. Even with revo and a D term in the controller I couldn't get rid of that. Here too I hope that heading-hold will do the trick.

EDITII (Oct. 23 2011): heading hold is now fully implemented and IMHO working quite well. Newer videos demsonstrating the claims are available on my blog on this project (www.olliw.eu).
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Old Jun 03, 2011, 04:20 PM
OlliW
Joined Sep 2009
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Fini

To summarize:
I guess you sensed by now why I called this the most "stupiest" approach to a BLBL conversion... it was a lot of work (but also a lot of fun ), and still will require a lot of work to improve it further... there would have been certainly faster ways to get to a BLBL lama (e.g. using Achim's mixer, which I did and which worked seamlesly). However, why did I call it also the most simple approach? Well, in terms of item count it certainly is. Also, there are garantueed no hazzles with incompatibilities of certain gyro - reciever - mixer combinations. And finally, once all pieces are in hand, it is just a matter of a "bit" of work to get a very functional BLBL conversion.

So far I do in fact not know how functional the gryomixer actually is, since I have tested and used it only on my platform so far... but there, I am pleased. In the meantime Tommy@LA implemented it also successfully in his BLBL Big Lama. Luvmyhelis has also gotten some gyromixers, but - as he showed interest in this project at a very early stage - he got the earliest versions, and has to deal now with their shortcomings. However, I think that in the meantime they became more reliable, also because the "don't do's" are better known.

What could be the future? Well, bugs may of course still be there and improvements hence required, but I think that as it is currently the gyromixer is performing well. A major next step would be adding a lipo saver, which is possible with the GA250 hardware but needs a bit more elaborate soldering work, but it's quite doable. The soldering work I have in fact done now in two cases, a gallery of pictures describing that can be found here, http://www.olliw.eu/2011/ga250-fpkoa...cher/#10082011, but no firmware which would use this optioin is yet available.

And finally, as stated in the above, if you are scarerd off by the soldering and programming parts, but otherwise would like to attempt this project, I think we may find an arrangement.

Have fun,
Olli
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Old Jun 03, 2011, 04:21 PM
OlliW
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Summary of Firmware, Software and Hardware

Latest Firm- and Softwares

GA250 Gyromixer Firmware , Version 0.22: GA250_Coax_GyroMixer_Firmware_v022.hex

Programming Box Firmware, Version 0.14: Olliw_GA250_ProgBox_v014b_m88.hex or Olliw_GA250_ProgBox_v014b_m88pa.hex, depending on the uC of your box

AvrConfig Windows GUI, Version 0.16

These files are available as .zip here: http://www.olliw.eu/uploads/olliw-ga...2012-01-22.zip

Unfortunately, some person seems to intend to not play by the rules, and I hence inactivated the links for downloading the firmware/software. It is still available for free under the conditions stated in the above, but I kindly ask you to register on my web page and to download from there. Sorry for the inconveniences.

Possible Setups
I shortly describe the possible configurations and which hardware/software is needed to get a running system (excluding hardware/software needed for actually building things).

You will - obviously - need the GA250 gyromixer (first attached picture). Additionally you should have the USB-Programming adapter, which consists of a USB-TTL adapter and a selfmade "plug-button-wire-assembly" (last attached picture). Finally you may wish to have the programming box (second attached picture), which is optional but (IMHO) very handy. Pictures of these three units are attached below for better overview.

Working configurations are:
1) GA250 gyromixer + programming box (+ servo cable)
2) GA250 gyromixer + USB-programming adapter + AvrConfig PC program (+ usb cable)

For flashing a new firmware onto the GA250 gyromixer and/or the programming box you need:
USB-programming adapter + AVRootLoader program (+ usb cable)

If you build the gyromixer (and/or the programming box) yourself, you will additionally need an AVR ISP programmer for burning the bootloader into the GA250 (and/or the Robbe Box)(plus cables to solder to the ISP pins). In order to simplify this step I wrote a little Windows GUI program, which I called AvrBurnTool, and which guides you through the process in six simple steps.

Functions of the Servo Plugs on the GA250 Gyromixer
The five servo cables coming out of the GA250-gyromixer are (please compare with the first attached picture below):
- four-wired servo cable with BLACK heat shrink tube: red servo plug = throttle, black servo plug = rudder
- servo cable with RED heat shrink tube: connector to the BESC for motor A (upper rotor)
- servo cable with BLUE heat shrink tube: connector to the ESC for motor B (lower rotor)
- servo cable with YELLOW heat shrink tube: I will call it the PROGRAMING CABLE, it has a triple functionality:
1) connector for flashing a new firmware into the GA250 gyromixer
2) connector for parameter setting via the AvrConfig PC program
3) connector for parameter setting via the programming box

Further Info on the Operation of the GA250 Gyromixer
- The gyromixer can be in a couple of different states, which are indicated by the LED signals. The possible states and the meaning of the LEDs are described in post #160.
- After powering up, the gyromixer waits for certain conditions to happen before it proceeds and actually outputs a PPM signal to the motor BESCs (on the respective plugs, see above). In particular, the gyromixer allows to calibrate both motor BESCs simultaneously WITHOUT having to disconnect the BESCs from the gyromixer or any other "tedious" procedure. These things are (briefly) described in post #162.
- Some ideas on how to tune the parameters of the GA250 gyromixer for finding a first reasonable parameter set are described in post #189.
- an explanation/overview of the gyromixer parameters, and their relative importance is here
- a comment on the four parameters Gyro Mode, Rate Gain, PID Gain and PID I is here
- an effort to explain what P, I, D of a PID controller are is here
- if you are confused by all these things such as ISP AVR programmer, USB programming adapter, USB TTL adapter, USBasp, Arduino USB adapter you may look up this post here
- the rcgroups members bebev and jrjr have some additional good information and reports on their blog pages!


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Saftey Precautions and Warnings

Pay attention to the correct polarity then connecting the servo plugs. This holds true in particular for connector Mot A as it is not protected internally by a resistor and is hence more susceptible to overvoltages.

You must not apply more than 5V to the power-plug at the usb adapter. 1S of a lipo battery works fine. With the usb-adapter AND the motor BESCs connected to the gyromixer, it is safer to not power the gyromixer through the battery plug at the usb-adapter.

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Hardware for Modding the GA250
1 x ASSAN GA250 (Hobbyking)
2 x servo extension cables (e.g. 40CM Servo Lead (JR) 32AWG Ultra Light 10pcs/bag, Hobbyking)
1 x piece heat shrink tube 2mm red
1 x piece heat shrink tube 2mm blue
1 x piece heat shrink tube 2mm yellow
1 x piece heat shrink tube 3mm black
1 x piece heat shrink tube 5-6mm black

Additionally an AVR ISP programmer is needed for setting the fuses and burning the bootloader.

A gallery of photos which presents the current remodeling of the hardware in much more detail can be found here: http://www.olliw.eu/2011/ga250-fpkoa...cher/#21072011 ATTENTION: it shows photos with fuses settings which are NOT correct, please use the fuse settings given in this post here below!

Fuses and Bootloader for the modded GA250
lfuse: 0xBF
hfuse: 0xDC
bootloader hex file: BL_4GA250GyroMixer.hex

The fuses are set and the bootloader permanently burned into the microcontroller using an AVR ISP programmer. It has temporarily to be connected to the ISP pins on the GA250 print board; the location of the ISP pins can be seen in post #3 in the first photo (see to the left).

----------------------------------------------------------------------------------------------------------------------------------

Hardware for Building the USB-Programming Adapter
1 x USB-TTL adapter with FTDI FT232RL chip
1 x servo extension cord (e.g. 40CM Servo Lead (JR) 32AWG Ultra Light 10pcs/bag, Hobbyking)
1 x switch
1 x male pin connector 2.54mm with 6 pins
1 x male pin connector 2.54mm with 3 pins
1 x heat shrink tubes as liked
1 x maybe a small piece of evtl. kleines Stück strip board 6×4 holes
1 x maybe a small piece of evtl. kleines Stück strip board 3×3 holes

It's IMPORTANT to use an USB-TTL adapter with FTDI FT232RL chip. Suitable items would be e.g. SparkFun DEV-09873, DEV-09716, or if no plug is desired DEV-10008. My current best suggestion is to use the Arduino USB adapter which are available for less than $10, e.g. at dealextreme or ebay. I recall, pay attention that your USB-TTL adapter uses a FTDI FT232RL chip!

The other stuff is needed to build the "plug-button-wire-assembly" which goes between the USB-TTL adapter and the GA250 gyromixer. The scheme you may find here http://www.olliw.eu/2011/ga250-gyro-...rammingadapter. The resistor R* is not needed for the gyromixer project and can be just a short.

The materials list is just a suggestion of what you may need as there are infinitely many ways to build the "plug-button-wire-assembly" (I myself e.g. are doing it differently now)!

Software for the USB-Programming Adapter
The usb-ttl adapter which is needed here has to have a chip which allows to invert the RX and TX lines. I myself am familiar only with the FT232RL chip. In principle any usb-ttl adapter with this chip can be used. Softwarewise the VCP driver is required, but I recommend to host also the respective D2XX driver and FT_PROG utility program in your GA250 gyromixer folder. If you build the USB-programming adapter yourself, you have to invert the RX and TX pins, which can be done by the FT_PROG utility program, which needs the D2XX drivers.

VCP driver: http://www.ftdichip.com/Drivers/VCP.htm
D2XX driver: http://www.ftdichip.com/Drivers/D2XX.htm
FT_PROG: http://www.ftdichip.com/Support/Utilities.htm

For more descriptions on inverting the RX and TX pins and using FT_PROG go to post #223.

----------------------------------------------------------------------------------------------------------------------------------

Hardware for Modding the Robbe Programming Box
1 x Robbe Roxxy BL Controller Programmer V2 No. 8642
1 x servo extension cord (e.g. 40CM Servo Lead (JR) 32AWG Ultra Light 10pcs/bag, Hobbyking)

Additionally an AVR ISP programmer is needed for setting the fuses and burning the bootloader.

Fuses and Bootloader for the modded Robbe Programming Box
lfuse: 0xCF
hfuse: 0xDF
efuse: 0x4F
bootloader hex for Atmega88: BL_4RobbeProgger_m88.hex
bootloader hex for Atmega88pa: BL_4RobbeProgger_m88pa.hex

Which of the hex files has to be used depends on which microcontroller (ATmega88 or ATmega88PA) is found in your Robbe Programming Box.

The fuses are set and the bootloader permanently burned into the microcontroller using an AVR ISP programmer. It has temporarily to be connected to the ISP pins on the Robbe Box print board; the location of the ISP pins can be seen in post #4 in the first photo (see to the right).

-----------------------------------------------------------------

Software for Flashing the Firmwares into the GA250 Gyromixer or Programming Box
The firmwares are flashed into the GA250 gyromixer (and/or programing box) by connecting the device via the USB-programming adapter to a computer and running Haagen's tool AVRootLoader.

AVRootLoader: http://www.mikrocontroller.net/topic/95839#new

-----------------------------------------------------------------

AVR-ISP Programmer
Any AVR-ISP programmer will be suitable.

As there are really quite many different units available, no further comments as regards usage shall be made here, the other sections at rcgroup or google will help. A very popular AVR-ISP programmer is USBasp, which is available for less than $5 e.g. at hobbyking or ebay. Several softwares are suitable to run it, the most basic and in some way most reliable is maybe avrdude, but it's a command line program and not GUI based.

I have written a little Windows GUI tool I called AvrBurnTool which you can run on your PC and which simplifies using the AVR-ISP Programmer and the burning of the bootloader, firmware and setting the fuses quite significantly. I have not yet officially released it and hence the info is a bit stretched out. Info you can find in post #307 and the zip file for download here http://www.rcgroups.com/forums/showt...0#post21029292 (with further info albeit for the different but related coaxmixer project).

Some time ago I was not aware that the Arduino USB adapter and USBASP programmer are avaliable together for less than $15 incl. shipping, and hence recommended using the SparkFun USB-TTL adapters as they can be used for both the USB-programming adapter and as AVR ISP programmer. This works, but (miss)using them as AVR-ISP programmer is tedious for the unexperienced (I estimate that about 75% of the first 200 posts here are on this)(I applogize, Randy). I keep this note only for historical purposes, since related pieces of information can be found from post #72 on until about #150 or so...

-----------------------------------------------------------------

Pictures of the GA250 Gyromixer, Programming Box, and USB-Programming Adapter
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Old Jun 03, 2011, 04:53 PM
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OlliW, you rock my friend! What you just did is greatly simplify my latest mod by eliminating the DD mixer/G110 combo and giving me much greater versatility by eliminating the piezo. Thank you bro! I just posted this new build of mine pictured below, so now it looks like I may have to spend some time behind my soldering iron this next week doing your beautiful mod! If you weren't a guy I would fly over and kiss you bro!
This is huge, just huge, I have the GA-250 and was trying to integrate it into the build. This dumps weight, eliminates components, and works great in confined spaces. KJ, if you are seeing this, this mod answers the problem with getting a brushless mod into your small walkera.
Nicely done Olli, nicely done!

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Old Jun 03, 2011, 05:18 PM
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By the way Olli, I just posted up a link at the HF CX site linking this thread so they can also look at your work.
http://www.helifreak.com/forumdisplay.php?f=119
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Old Jun 03, 2011, 05:27 PM
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Congratulatiuon!!! Great stuff, Olli
The videos show that it works very stable so far.
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Old Jun 03, 2011, 05:34 PM
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By the way, does the intoduction of the new Assan GA-250 gyro that is capable of running an analog servo change any of the design application here? These new next gen gyros are supposed to be hitting the shelves as we speak. I emailed Dan back at Dionysus and let him know about the gyro, since even with his plug and play DDmixer this gyro is a game changer. It removes the piezo completely from the formula.
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Old Jun 04, 2011, 01:02 PM
OlliW
Joined Sep 2009
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@4712: nice that you are still with us here
Quote:
The videos show that it works very stable so far.
äh, oh, I forgot to mention the weaknesses... I edited the above post accordingly... they might not very well be seen in the videos, but I think there is still room for improvement... but as a first step, it's not too bad either...

@Luvmyhelis
Quote:
does the intoduction of the new Assan GA-250 gyro that is capable of running an analog servo change any of the design application here
as long as the hardware didn't change it doesn't matter, remember that you have to flash the uC with your software anyhow, so whatever the code was before it's going to be overwritten
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Old Jun 04, 2011, 03:05 PM
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Quote:
Originally Posted by OlliW View Post
@Luvmyhelisas long as the hardware didn't change it doesn't matter, remember that you have to flash the uC with your software anyhow, so whatever the code was before it's going to be overwritten
Thanks, I wasn't sure which part was being overwritten so I had to ask. Also there is some interest on the Assan GA-250 cheapest memms gyro site about your invention. And another link popped up there. The question of coarse is about the hh function. Here is the link to the 3d stab system that I knew nothing about, I like the small size.
http://code.google.com/p/phubar/

I was thinking late last night, since the system you made can be made with a link for a low batt light, why not provide a link for a lighting system that will shut off at 3.2v instead? I never use HH in a coax so I am not too worried about the novelty of hh when you look at the superiority of the memms system it may not be needed.
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Old Jun 05, 2011, 05:54 AM
OlliW
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Hey Luvmyhelis
Quote:
there is some interest on the Assan GA-250 cheapest memms gyro site about your invention.
well, at the moment it rather seems that you are the only one interested in this "invention"

Quote:
since the system ... can be made with a link for a low batt light, why not provide a link for a lighting system that will shut off at 3.2v instead
in principle that's no problem, the lightning system would only has to "understand" this link or switched off from power e.g. with a suitable transistor, but that's nothing which could not be done... in principle... the limitation here is just our imagination.

Quote:
I never use HH in a coax so I am not too worried about the novelty of hh when you look at the superiority of the memms system it may not be needed.
I think MEMS does only make sense with HH, because in rate mode you have all sorts of reasons for a drift; gyro drift is only one and IMHO the least important one. So, I think in rate mode the difference between piezo and MEMS might not be spectacular, and rather hard to notice. However, in HH mode (if things work properly) the drift is only limited by the gyro drift.

Quote:
The question of coarse is about the hh function.
there is no question, the principle is quite clear... I am in fact working on implementing that at this very moment... and a first version is doing already something...

Olli
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Old Jun 05, 2011, 06:37 AM
It flies!!! ... so who cares ?
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Quote:
Originally Posted by OlliW View Post
Hey Luvmyhelis
well, at the moment it rather seems that you are the only one interested in this "invention"

...


Olli
Well Olli,

I guess the problem with people being "interested in this invention" is this:

For the large majority (and I am a bit sad I definitely have to include myself into this group of people, which I personally(!) believe (off course I might be terribly wrong and would have to be quite .) is the vast majority) this is the major problem ... all the principles, the technology, the design and the ideas - simply put everything that makes the final product work - are one (or in my case a few) levels above the degree of the matter that they really understand or want to really GET to understand ... I truly believe what is most important for most people in this hobby is that something works and they get it to work right - how you GET this "something" to work or more so 'work right' IMMHO is secondary concern for most of the "readers"
This, I believe is the reason that there is (in many cases) such a "low active participation" in the respective threads, which does absolutely not mean there is no interest! - the interest is just geared to a different aspect of the project.

Just to speak of myself, I would love for something like this being possible to just be purchased and used. The fact that it is an absolute DIY project (which, as I said is for many reasons rather far beyond my skills) will keep it most likely out of my reach until I leave the hobby (... in other words drop dead ...)

Anyway, just wanted to point out that I dont think there is a lack of interest in the product itself, but the "project" to create the product is just beyond what many can or want to deal with, which makes it seem like this.

I will keep on checking on this thread to read what all is possible, without truly understanding how you make it happen ...

E2
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Old Jun 05, 2011, 07:44 AM
OlliW
Joined Sep 2009
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Hey Sven,

thanks a lot for your comment.

I think I understand what you are saying. However, on the other hand, I think, it hardly can be simpler.

I mean, look at the multi copter forum, I think this is a very nice example of how thinks can work out. There you too find MANY people who do not and do not want to understand the code or how you said bother with how things were get to work (there are of course also quite a lot of true experts). Of these however there are quite many who are not afraid to purchase an Arduino, install a software on the PC, flash the uC, do some soldering work... they simply use the things which were developed, follow the "manual", and have fun. As a result many multi copters are build. This is noticed by entrepreneurs, they see a demand, and all of the sudden all sorts of stuff becomes available commercially... Finally, also those who "just" want to buy and use and have fun may also build their multi copter. And most importantly, all of these folks - from the experts to the just-buyers - all of them get help in the threads.

Unfortunately, in the coax forum(s) (not only this one), this sort of culture did not develop.

In the particular case of this project, I understand that only very few will be interessted to really dig into the details. However, I think it's made simple enough such that anyone who doesn't want to dig into the details, but doesn't bother to solder few cables, install software on a PC, and flash a uC either, can easily do the build. And for all the others who wouldn't wish to go even that far I did add a specific final comment.

IMHO the story is somewhat similar to Achim's coax mixer. I think quite some of you got a mixer from Achim. So, what's the problem? (I am afraid though that Achim's forthcomingness will not be rewarded by corresponding build posts). Also, in the German forum I once initiated a collective order for the mixer print board - and you know what? - about 15 persons signed up - and only this way nice print boards became available for many people.

So, my short answer to your response is:

I think it is not yet fully appreciated what a community could be for.

Have fun,
Olli

PS: I hope my comments do not come across harsh... if so, I appologize... you know, I am not using my mother tongue, and Germans tend to be a bit too upfront... I defenitely didn''t meant to offend anyone, and in particular not you.

PPS: by the way, I have not expected at all - and do not expect - that this thread creates much interest, but exactly because of that and the context you mentioned, I found Luvmyhelis comment kind of funny, there is a sort of humor to it
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Old Jun 05, 2011, 01:07 PM
It flies!!! ... so who cares ?
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hey Olli,

cant really offend me with telling me anything is possible if you really want to (well to a certain degree anyway).
Let me add another thought to what I said earlier on. (yes btw, to a degree it is no (yet?) appreciated what a community can do ... as you said).

So here is the other thought I just had reading your last post. Apart from people no wanting to "dig deeper" or maybe really lacking some skills (you know I "speak from experience") dont forget that a coax is almost exclusively seen as first and foremost a beginners heli ... so many people will have long moved on from the coaxes (if they stick with the hobby) before the develop the interest to dig deeper, the skills you need to do so or both.

Just look at my personal "progress" - I am writing a lot about coaxes and I try quite a few things every once in a while (of course on a way less sophisticated level than you do) ... but the coax I actually FLY the most right now is the S107 (a 3ch - which I would have never ever have expected) - BUT ... the challenge that I gave myself is that I want to learn how to actually FLY a Walkera 4#3BV3 double brushless (so at least I dont have to do a conversion ...) Anyway, I guess what I want to say is that coaxes are widely regarded as nothing but a stepping stone to "actual" heli flying - which might also explain a bit of the lack of dedication that many pilots on these coax forums exhibit when it comes to the "science of the RC coax" ...

E2
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Old Jun 05, 2011, 01:54 PM
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Thanks OlliW, I am one of those people who are going to build a few of these. As soon as my slate of ongoing projects lessens I am pulling out the ol soldering iron and getting at it. I do have a quick question, is the programmer commercially or privately available? Right now I don't feel like building up both of these. I have the skills but not the desire. Also, is it possible to back track and mod your first posts to include the addresses of some of the better sites in which to buy smaller quantities of the parts needed? I just spent hours on one purchase of a pair of capacitors I replaced on my CC Ice 50 esc yesterday, so I know how time consuming a parts roundup can be.
Two years ago I posted a guide on replacing the easily burnt chips in the 3in1 eflite coax controller. Not a single person ever used it! They would rather spend $30 to $40 on a new 3in1 than spend 2 hours and $5 repairing one.
I have also seen more than just a tendency amongst coax enthusiasts to stay basic and cheap with plug and play options, correct this, I have seen this same tendency even in the CP world. As you mentioned there is more interest in the multi copter section for these improvements. For some reason that venue seems to attract more tech minded people, and has for years. Even the cheaply built quad rotor frames bring in huge money. It astounds me when those guys will step up and pay over $100 for $8 in Carbonfibre, and they seem to have no problem paying for 5 to 6 hundred dollar stability units. That most certainly is at the opposite end of the extreme from what I have witnessed on two of the largest helicopter forums as far as coax tech goes. I can say without error that I have only seen half a dozen guys even attempt a very basic and simple brushless upgrade since I have joined them well over two years ago. And as far as a very simple mechanical dual swash mod, no one.
Even on the CP forums the mods I have done to my 450 CP project have not been replicated in whole by any single person, so this is more the norm in the hobby than the exception. I say this not to condemn the sites involved nor the hobbyists but as a statement to clarify that what you have done is exceptional in nature and actually what is simple to you is far above the average guys desire and ability to replicate. I cannot tell you how many threads I have seen where guys can't even solder a battery lead!
So in the end don't take it as a personal rejection when there isn't a huge response to your lead. And honestly this same attitude has had an impact on my 450vtail dual swash flybarless since there has been 0 interest expressed anywhere by guys willing to replicate the effort. So I have been in no hurry whatsoever to finish it.

In looking for the last two years at how few people even looked at the simple brushless coax threads for both eflite and esky, even walkera, much less the few that commented I understand your confusion. This does not mean that your effort should not have been done, nor that eventually it will not be appreciated. I linked your thread to more than one software designer/electrical engineer that I know. And there is simply no way the impact of the process went unnoticed by them.
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Old Jun 05, 2011, 03:23 PM
OlliW
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Sven, Luvmyhelis,

please don't get me wrong. Before I considered posting it was absolutely clear to me that it is not going to attract many people and I posted it being fully aware of that. So that's not the point. Also, I do not expect at all that anyone is going to replicate any of my projects - I mean, I wouldn't do that myself, I would collect the available ideas, would add mine, to end up with a result which suits my very personal needs. So, if it provides ideas and useful info, which would stimulate and help others, this would be perfectly fine.

Sven, I fully comply with you what you said about coax, and I would have added what you, Luvmyhelis, said, namely that this seems to be characteristic for the heliworld (as oposed to the multi copter techi's)(though I have seen quite many coax BL mods in Germany).

By the way, this part of the discussion just emerged because I responded somewhat jokingly to the comment of Luvmyhelis that this project has attracted some interest, which I found - becasue of exactly the context you both described- kind of funny...

So much to that.

Quote:
is the programmer commercially or privately available?
not sure I understand exactly what you mean by that.

Both the Assan GA250 and the Robbe Programmer Box V2 No. 8642 are commercially available (and both are, considering what they provide, IMHO quite cheap). Both, however, have to be reflashed, i.e., a new software has to be programmed into them. For that you need an ISP programmer for Atmel micro controllers and a corresponding (PC) program. The ISP programmer plus software is also commercially available (and is cheap too) (but also simple DIY projectes exist, which, since the commercial ISP programmers are so cheap, are not really money savers). Additionally you need some servo cables with plugs according to your needs and wishes.

So, hardware-wise you need (all can be purchased):

- GA250
- Robbe Programmer Box V2 No. 8642
- Atmel ISP programmer
- cables, wires, plugs, and such stuff (can be purchased even configured)

You also need quite some software:

- a PC program to operate the Atmel ISP programmer (comes with the ISP programmer or can be downloaded for free)
- Haagens AVRootloader program (can be downloaded for free, I can direct you to a link or provide it)
- four .hex files with the softwares which have to be flashed into the uCs. These files I should provide.

As regards vendors, I think I am not a good advisor, since I am located in Germany...

Äh, I should not forget that, you need both the GA250 and Robbe Programmer Box, since without the Robbe box you would not be able to adjust any of the parameters.

Olli
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Old Jun 05, 2011, 08:39 PM
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Thanks Olli. Questions answered. I already have the GA-250 since I picked one up to play with a few months ago, now I just need the related parts to do the mod and will spend some time rounding things up. But they are cheap enough not to worry about.
Randy.
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Old Jun 06, 2011, 12:55 AM
OlliW
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oh, dammed, I forgot to list an additional piece of hardware you need, which, unfortunately, is in fact the one which needs most hand work - namely the bootloader connector. The Bootloader connector is then made of

1x resistor, 2x Schottky diodes, 1x RS232 connector (top picture)

If you have PC which provides a serial connection (RS232), then you may use that directly. If you wish to use USB, you have to emulate a RS232 connection. This can be done with the commercially available USB to RS232 converters (which are cheap too) plus some software (which comes for free). In that case you additionally need

1x USB to RS232 converter

Achim reported that the bootlader can also be used with one of the USB to TTL converters, but I have never used that. I will ask him. This could be the easiest solution.

Sorry for having forgotten this crucial part. I will think about that further to determine a most simple solution.

Olli

Attached the figure for the bootloader connector from Haagen (top picture)
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Old Jun 06, 2011, 06:38 AM
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Simply wow!

This is awesome stuff here!

Olli, you rock!

I haven't even finished my vtail mod yet, and now I want to try this out. One thing at a time but this looks to cool, I can't resist.

You guys are way beyond me and my capabilities in the electronic world, but I still enjoy the hell out of mimicing what you do...and this one looks like a blast!

after my vtail mod is sucessfull, this will be the next project...thanks Olli, your work is appreciated.

John
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Old Jun 06, 2011, 08:41 AM
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hi.olli,

your works looked good,that make me thinking develop such products too


meng
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Old Jun 06, 2011, 10:30 AM
OlliW
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hi.meng,

i know that you asian people are always quick with copying others ideas

olli
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Old Jun 06, 2011, 02:50 PM
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Hi Meng,
Quote:
Originally Posted by ASSAN View Post
hi.olli,
your works looked good,that make me thinking develop such products too
Well, let me think straight forward:
How about releasing the GA-250 firmware as opensource and also integrate some simple options (as Lipo Vbat input and BESC outputs) into the hardware layout.
We would make the GA-250 the runner of the year!

BTW: http://www.rclineforum.de/forum/boar...-deluxe-baube/
my project of a coax mixer with Lipo Saver (reducer), integrated 11 step throttle curves, Windows setup application...

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Old Jun 06, 2011, 08:25 PM
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Quote:
Originally Posted by OlliW View Post
hi.meng,

i know that you asian people are always quick with copying others ideas

olli
Dear Olli,

what i think is if there have many coax pilots need such items,and more than 99% not smart or have electronic skill like you,why not make the things sample enough for such guys?

and, honest, GA250 is not a good business because it's couldn't earn enough money to balance the cost. we need find more to expand the product line.

we are thinking,not decided.

yours,

meng
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Old Jun 06, 2011, 08:30 PM
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Quote:
Originally Posted by 4712 View Post
Hi Meng,


Well, let me think straight forward:
How about releasing the GA-250 firmware as opensource and also integrate some simple options (as Lipo Vbat input and BESC outputs) into the hardware layout.
We would make the GA-250 the runner of the year!

BTW: http://www.rclineforum.de/forum/boar...-deluxe-baube/
my project of a coax mixer with Lipo Saver (reducer), integrated 11 step throttle curves, Windows setup application...

hi,

your project looked also good for me.but open source is not good idea for GA250's case recently.because i am business man. GA250 is take an important role in our game.we can't take a risk to do something maybe will hurt the business.sorry,guy.


meng
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Old Jun 07, 2011, 01:24 AM
OlliW
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Dear Meng,

first, in principle there is nothing to add to my comment, and you know that.

second, please don't assume that we are fools and please don't make a fool out of yourself by repeating these ridicuolus typical "arguments". Such as "and, honest, GA250 is not a good business because it's couldn't earn enough money to balance the cost", yeah, yeah, yeah...

(you can't tell us in one breath that you are a bussiness man and that you are not a bussiness man)

Ok, so we have mutually agreed herewith to talk serious.

I think that Achim is a very smart person, and made a very smart suggestion. In most cases gyros are (or had been) quite expensive, not because of the large material/fabrication costs but because all the development costs have to be rated in (and the good share sellers want to make). This way, however, you will never end up with a high-quality and cheap product. So, I would think that it would be in your best interest to get the software and development for free, because either you will never be compensated for the development costs or you will never be able to develop a product which functionwise will get out of the its-cheap-so-its-ok-if-its-not-working-very-good corner (and even though you wouldn't do that openly I guess we agree that the latter is your problem with the product). No costumer will ever assume that a 10$ gyro will be developed to such a degree that it will function well and safe enough to plug it into a 1000$ helicopter... even a single crash with a HK helicopter because of a malfunction of the gyro will be more expensive than to buy one of the apporved brands from the begining. Of course, there is a risk, but there is always a risk in everything. In this case the fear of risks appears to me as the largest risk. Open source has proven in the past to be able to produce high-end software. You would save money because you would not have to develop the software, you would earn money because you could provide an approved high-quality software. To me it sounds very smart to provide a good and cheap hardware plattform with a high-end open-source developed software.

Now, my 2 cents to my comment and your response "why not make the things sample enough for such guys". In our Western countries we have a particular understanding of intellectual rights. So, your question is at best quite naive.

Furthermore, what you do not seem to understand is that it's exactly because of this sort of behaviour you suggest, which is harming, not me, not you, but people. To make it very specifc. People stop to provide and share information openly, in forums like rcg, but also in society-wise more relevant environments. More concret, I do see this in many occasions happening, that as soon as a chinese is around one starts to be very wary with what sort of information one is sharing. And you hardly can complain about that, because it's your own behavior which way too often justifies exactly this. You may earn a quick buck, but its slowing down your development.

So, since this is a bit OT, I'd like to finish it and repeat,

Quote:
i know that you asian people are always quick with copying others ideas
but of course you are free to proove me wrong by your actions.

Olli
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Old Jun 07, 2011, 02:50 AM
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Quote:
Originally Posted by OlliW View Post
Dear Meng,

first, in principle there is nothing to add to my comment, and you know that.

second, please don't assume that we are fools and please don't make a fool out of yourself by repeating these ridicuolus typical "arguments". Such as "and, honest, GA250 is not a good business because it's couldn't earn enough money to balance the cost", yeah, yeah, yeah...

(you can't tell us in one breath that you are a bussiness man and that you are not a bussiness man)

Ok, so we have mutually agreed herewith to talk serious.

I think that Achim is a very smart person, and made a very smart suggestion. In most cases gyros are (or had been) quite expensive, not because of the large material/fabrication costs but because all the development costs have to be rated in (and the good share sellers want to make). This way, however, you will never end up with a high-quality and cheap product. So, I would think that it would be in your best interest to get the software and development for free, because either you will never be compensated for the development costs or you will never be able to develop a product which functionwise will get out of the its-cheap-so-its-ok-if-its-not-working-very-good corner (and even though you wouldn't do that openly I guess we agree that the latter is your problem with the product). No costumer will ever assume that a 10$ gyro will be developed to such a degree that it will function well and safe enough to plug it into a 1000$ helicopter... even a single crash with a HK helicopter because of a malfunction of the gyro will be more expensive than to buy one of the apporved brands from the begining. Of course, there is a risk, but there is always a risk in everything. In this case the fear of risks appears to me as the largest risk. Open source has proven in the past to be able to produce high-end software. You would save money because you would not have to develop the software, you would earn money because you could provide an approved high-quality software. To me it sounds very smart to provide a good and cheap hardware plattform with a high-end open-source developed software.

Now, my 2 cents to my comment and your response "why not make the things sample enough for such guys". In our Western countries we have a particular understanding of intellectual rights. So, your question is at best quite naive.

Furthermore, what you do not seem to understand is that it's exactly because of this sort of behaviour you suggest, which is harming, not me, not you, but people. To make it very specifc. People stop to provide and share information openly, in forums like rcg, but also in society-wise more relevant environments. More concret, I do see this in many occasions happening, that as soon as a chinese is around one starts to be very wary with what sort of information one is sharing. And you hardly can complain about that, because it's your own behavior which way too often justifies exactly this. You may earn a quick buck, but its slowing down your development.

So, since this is a bit OT, I'd like to finish it and repeat,


but of course you are free to proove me wrong by your actions.

Olli
Dear Olli,

thanks for wrote a long letter to talking about this matter.something you said i agree,something you said i don't agree.

we have no interesting to got any free software or code. we have engineers teams and you know most enginners want build their own projects,not copy.

and, about coax,i just thinking maybe we can do a gyro +mixer+spektrum sat port after read your thread.your work expand my scale,thanks.i always think coax is a toy, we have no interesting to jump in it because most coax need N in 1 and with very low price before(there have under 15 usd coax in chinese market with gyro).now, we have a cheapest MEMS gyro and why not move such project in high end coax,like 450 size helis?

open resource is some good for some items/projects. not all. in my optio, ga250 is not suit to open.maybe we will conside open something in the future,like program box,multi copter controller or something we think it's suit to open.

meng


ps:[/QUOTE]
[/QUOTE]
i know that you asian people are always quick with copying others ideas [/QUOTE]


but of course you are free to proove me wrong by your actions.[/QUOTE]

N in 1 is not a copy idea.

and, in another side,you use our GA250 to do such project,the hardware belong us,it's our idea.you use it, did that means a copy action?
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Last edited by ASSAN; Jun 07, 2011 at 02:57 AM.
Old Jun 07, 2011, 03:06 AM
We can rebuild it!
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Olli, love this thing you have done! from what I have read here and watched on youtube finding the correct combo of Gyro and mixer are a problem.

Now about the size and weight of this unit, in some of my micro (Toy grade brushed motor) helicopters I would to install a 2.4Gh Rx and a Gyro.... could it be programmed to give a motor driving PWM to which I could connect MOSFETs and drive the brushed motors? Essentially turning it into a 4-1 Gyro, mixer & Dual brushed ESC.
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Old Jun 07, 2011, 03:23 AM
OlliW
Joined Sep 2009
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Quote:
in another side,you use our GA250 to do such project,the hardware belong us,it's our idea.you use it, did that means a copy action?
LOL... you ignore two most important points, 1) I am openly revealing my sources and 2) I did pay money (to you) for the idea of the hardware. (and BTW if you open other MEMS gyros you find very similar hardware, so it's ridiculous to claim that it's all your idea, if it would be so you should sue your competitors). That's ridiculous and my comment stands still unrefuted.

Anyhow, I think everyone had a fair chance to express their views now, and as the master of the thread I will close the discussion on this topic.

Let's return to the fun part.
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Old Jun 07, 2011, 03:31 AM
OlliW
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Hey djdavies83,

well, it probably could, but I think that's exactly what one would not want to do, because units which incorporate gyro, mixer, and PWM output for brushed motors are existing already in abundance, they are known as 3in1. So, if you look for a 3in1 for a coax you will find many options (and some of them cheap). You will also find many DIY projects which describe of how to connect your own MOSFETs to them.

I do not have a good overview of the available 3in1 (I only know the ESky 4in1/3in1), and hence can't give you an advice here, but I know that in this forum there are folks which will know everything about that.

Have fun,
Olli
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Old Jun 07, 2011, 04:27 AM
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Quote:
Originally Posted by OlliW View Post
Hey djdavies83,

well, it probably could, but I think that's exactly what one would not want to do, because units which incorporate gyro, mixer, and PWM output for brushed motors are existing already in abundance, they are known as 3in1. So, if you look for a 3in1 for a coax you will find many options (and some of them cheap). You will also find many DIY projects which describe of how to connect your own MOSFETs to them.

I do not have a good overview of the available 3in1 (I only know the ESky 4in1/3in1), and hence can't give you an advice here, but I know that in this forum there are folks which will know everything about that.

Have fun,
Olli
I have to add though to this, most if not all of the commercially available 3 and 4in1's are very poorly built, poor performing electronics. This is why most of the true modders dump the 3in1 right off the bat and go boardless with a separate much higher quality gyro. Even adding your own mossfet chip does not solve the intrinsic gyro weakness nor does it solve the brushless phasing requirements needed for more efficient motors, unless you are ground up purpose building a new system to address these problems. As of yet I have not seen a comprehensive system that has addressed all of these.
Thank you Assan for weighing in here and sharing your opinion. And thank you for supplying a very high quality gyro that we can use and mod to achieve the higher results we require to forward this venue. So OlliW let me ask a quick question since you posted another small required link. This insinuates to me that a simple usb link will not work to program the system?
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Old Jun 07, 2011, 04:58 AM
It flies!!! ... so who cares ?
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Quote:
Originally Posted by OlliW View Post
LOL... you ignore two most important points, 1) I am openly revealing my sources and 2) I did pay money (to you) for the idea of the hardware. (and BTW if you open other MEMS gyros you find very similar hardware, so it's ridiculous to claim that it's all your idea, if it would be so you should sue your competitors). That's ridiculous and my comment stands still unrefuted.

Anyhow, I think everyone had a fair chance to express their views now, and as the master of the thread I will close the discussion on this topic.

Let's return to the fun part.
One little addition - not only the one doing the project pays the money for the "idea" GA-250, everybody who wants to replicate this project through the sources described in this thread AND their own work, ALSO is going to pay money for the "idea" GA-250

If anyone uses this openly availble information to create a new commercial product based on it - even if this person makes a minor change in setup or a slight improvement so that it is no longer 100% identical - HOW MUCH money is OlliW going to "see" for HIS IDEA???

(It has been done here before that a member of the forum introduced an idea, willing to share it with the community, and one commercial follower in this community went and just used it in his/their products, practically identical and without acknowledging with a single word or a thank you that this info was provided - and THAT is why people with ideas and without the means to mass produce them dont like to willingly and openly share them anymore - because someone else is ... based on their possibilities of mass production ... making 'all the money that this intellectual property obviously is worth', without including them in the earning by even 1Cent!!! And of course, its also obvious why the commercial follower never thanked or did acknowledge the info of the member here - because if he had done, he would have been sued for a share of the profits!!!)

Cheap and good is a combination of very desirable qualities. Thanks to the very human nature (ie the inherent greed in so many of the human actions) this combination of qualities gets achieved only in the rarest of cases ...
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Old Jun 07, 2011, 06:28 AM
OlliW
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Hey Guys,

I very much appreciate all your opinions and it's an interesting discussion. However, I think we should not expand on this any further here. I'd like to close the discussion on this topic. Thanks.


@Luvmyheli:
One certainly cannot disagree with you on the quality of the 3in1. However, IMHO I find it impressive how well at the low cost they are actually working. They do their job, and without delivering this at a low price I guess the coax heli's would not exist.

Quote:
let me ask a quick question since you posted another small required link. This insinuates to me that a simple usb link will not work to program the system?
I noted that the procedure as it looks (and I am using it) at the moment is very inconvenient, but I promised to look for better solutions, and I think there are better solutions. Unless other folks jump in with their experience, I cannot however provide this solution quickly (I have to test first myself).

I'd like to state before more clearly what has to be done to get the software into the uCs. This, as I suggest it, and I guess most will find most convenient too, consists of two steps:

1) Flash the bootloader
First, a software called bootloader has to be programmed (flashed) into the uC. For that one needs a particular hardware-unit called AVR ISP programmer. In this step one has to solder (up to) 6 cables to the particular pads on the print board and connect them to the ISP programmer. Once the bootloader has been flashed, all these cables can permanently be removed, and in principle the AVR ISP programmer will not be needed anymore.

2) Flash the actual code
Once the bootloader has been installed in the uC, the actual coax gyromixer software can be flashed using an additional piece of hardware, I will call it henceforth the bootloader connector (to have a name for it). In this step the only thing to do is to connect the bootloader-connector to the specified cable coming out of the coax-gyromixer. Since the software may change frequently, because of bugs, or new options, etc., this step will be done frequently. But since one just has to connect to "things" it's easy.

So, you see, to get the things actually working one needs two additional pieces of hardware, the ISP programmer and the bootloader-connector. Of course, for all of this one needs the appropriate PC softwares. However, these come for free and "only" have to be installed on the PC (I am always assuming a Windos CP) .

Now, as I do it at the moment, I have a particular ISP programmer, a serial connection plus the 2-diode+2-resistor network as bootloader-connector. A ISP programmer can be purchased, a serial connection can be purchased too, but the 2-diode+2-resistor-thing you have to do yourself. However, as I said I perfectly understand that this is very clumsy and inconvenient. As regards a simpler solution I am thinking along two lines.

A) Using a FTDI-based USB-to-RS232 converter. These are cheaply available, e.g., at SparkFun.
In principle it is possible to use such a converter to flash the bootloader into the uC. This will be slow, but since this has to be done only once (for each uC) this should not be an issue. This converter can in principle also be used directly as the bootloader-connector without any need of additional diodes, resistors, etc.. (I learned this from Achim, all thanks to him ). Problem only, I have never done any of this myself before (and there could be a problem with the fact that one would operate at 5 V but the GA250 internally works at 3V). If this could be made to work, it would be a neat and most cheap solution. (it will need to pay some attention on the PC software, however)

B) Yesterday I found the Pololu USB AVR Programmer. The nice thing is that it provides BOTH an ISP programmer and a USB-to-serial converter, and it is also of acceptable price.
So, with this device doing the first step, flashing the bootloader, is no problem. Also, the second step should be no problem. However, a bit unfortunate, this device does not allow for inverted output pins. So, it will work for sure as a bootloader-connector if one is willing to add one or two resistors, but it might not work without any additional hardware. As before, I have never used the Pololu USB AVR Programmer. (PC software-wise this will be the most simple solution)


So, a simpler and cheaper solution shall be possible, and hopefully one gets away with only three items, a GA250, a Robbe Box, and a ISP-Programmer-Bootloader-Connector.

Olli
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Old Jun 07, 2011, 04:13 PM
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Hi Olli,
Quote:
Originally Posted by OlliW View Post
Hey Guys,
(and there could be a problem with the fact that one would operate at 5 V but the GA250 internally works at 3V)
One remark: on my FTDI board, there is a jumper to configure either 5V or 3.3V.
But to stay realistic: it simply reduces the level from 5V down to 4Vpp () ... But it should do no harm on the GA-250 chip.
Generally i prefer the ftdi usb chip, especially regarding time critical applications, but in my experiance the prolific usb/serial chip will do the job too...
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Old Jun 07, 2011, 09:50 PM
Fix, Fix, Fly, Fix, Fix, Fly
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Olli, great project! I know it may not seem like there is much interest but I think that E2 is right, most of us are very interested and are just to scared to try it ourselves! Keep the great info coming!

Also, I am getting one of Achim's mixers and will be doing a BLBL conversion. I plan on doing a detailed build log (at least as detailed as someone with my limited skills can do!), but due to funding restrictions it will probably take me 3-6 months to complete the project. I hope that I can do the mixer justice!
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Old Jun 07, 2011, 11:18 PM
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Thanks Achim for sounding in, Olli, thanks also for clarifying those things I needed. Mountainsax please do post up when you get to that point. This is all about common goals being achieved through group effort. We all learn from each other. This thread came along at a critical juncture for me since all the other avenues had already been pursued and achieved. I was dying of boredom. Unless I have at least three projects ongoing with different functions I go crazy.
This actually addresses 4 of my previous builds now that I can upgrade the gyro/mixers.
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Old Jun 08, 2011, 01:48 PM
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Did a 3in1 search..... got a load of random stuff like board games etc, The reasons I ask about brushed PWM on this unit is the price, size/weight and as quality of 3in1 borads that are in the helies at the moment, starnger question.......

Could this unit (once flashed, re-written and hard moddified) take a 3rd input (throttle, yaw and elevator) and give 4 PWM brushed motor outputs? really want to add 2.4Ghz and Gyro to a otherwise great (toy grade) tandem coax Chinook that I own.
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Old Jun 09, 2011, 01:53 AM
OlliW
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heading hold seems to work quite fine now...

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Old Jun 09, 2011, 10:50 AM
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Originally Posted by OlliW View Post
heading hold seems to work quite fine now...

Beautiful! the missing link has been solved. Nice work!
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Old Jun 18, 2011, 08:56 AM
OlliW
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Hey folks,

some good news.

It is indeed possible to do all programming and flashing of the GA250 and Robbe Box with only one piece of additional hardware, namely a USB-TTL-serial adapter, plus of course some little things such as cables, a switch, connectors, and so on.

It is important that the USB-TTL adapter uses the FTDI FT232RL chip (other might work but I have and will not check). Such units are available rather cheaply, which means about $15.

Flashing the bootloader via the ISP was in fact no problem at all. However, finding a working procedure for flashing the firmware via the bootloader I found actually not that simple (it at least took me quite some time). The main problem here was the power supply. Using an external voltage source worked very well, but I of course liked to use the internal USB power (to avoid the need of an additional hardware item), and it is here where I encountered serious problems. Apparently, the USB unit disconnects or is disconnected from the PC even upon a slight power drop, which is bad because the connection is lost upon starting the bootloader. As one part of the solution I found it nessecary to connect gnd of the USB-TTL adapter with the ground of the USB connector (these are by default not connected), otherwise things worked extremley unreliable. Not sure why this is so. The 3.3V source provided by the FTDI chip I found way too weak, but with the gnd-gnd connection the USB 5V source does provide enough power to prevent unintended disconnection. However, I didn't wanted a 5V signal level since the Atmega8 in the GA250 is operated at 3.3 V, hence a protection resistor would have been needed, which I didn't wanted to add since then the bootloader adapter cable would have to be different for the Robbe Box and the GA250 unit. Hence, as the second part of the solution, I use the 5V USB source to power the device to be flashed but connect the VCCIO pin of the FTDI with the 3.3 V such as to achieve the 3.3V signal level.

Having said this, it is clear that not every USB-TTL adapter will work for us, and almost always some (simple) modding is nessecary. I used the the sparkfun FTDI Basic Breakout - 3.3V (DEV-09873) board, but here two cables have to be soldered. I have not tested it, but the Breakout Board for FT232RL USB to Serial (BOB-00718) is probably the better choice.

In finding an appropriate USB-TTL adapter, an additional requirement is that it hast to provide, besides the Tx and Rx pins, at least also two of the additional pins, such as CTS and DTR.

Anyhow, with the BOB-00718 I think a reasonably cheap and simple solution is available.

Besides the hardware, also some software such as some drivers and some exe files need to be installed. However, all these software is freely available.

That's it,
Olli

PS: by the way, it appears that the Robbe Box is not easily available in the US. Can you confirm that or could you suggest a good source? Thx
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Old Jun 20, 2011, 02:45 PM
Professional heli wrecker
Luvmyhelis's Avatar
United States, WA, Spokane
Joined Oct 2010
4,172 Posts
I haven't found it here Olli. And at the start of this next month I am starting my build on one of these. Actually make that 4 of these in all since I am changing out my existing fleet using this mod. I will post up the results not only here but on the Vtail thread. If needed I can build a few xtras for other members as needed and will sell them at cost at the same time. IT seems once the effort is expended to set this up the remaining work is quite simple and only takes a small amount of time.
Can you post up how to set up the HH when you have time?
And in light of the problems still remaining a simplistic usb methodology might be needed. Your description of the changes in the VCCI0 pin need to be more specific for us simple guys!
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Old Jun 23, 2011, 06:39 AM
OlliW
Joined Sep 2009
1,454 Posts
Demonstrating the Claims II

just quickly two flight videos with the HH version of the gyromixer... no drift (well very minor drift), no bouncing, no break-out during full pitch...

unfortunately I still couldn't figure out of how to embeed videos here, hence again just links to the videos, sorry

http://www.olliw.eu/2011/ga250-fpkoa...23062011video1
http://www.olliw.eu/2011/ga250-fpkoa...23062011video2

(or for download http://www.olliw.eu/uploads/coax-gyr...-110623-wp.flv, http://www.olliw.eu/uploads/coax-gyr...-110623-wp.flv)
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Last edited by OlliW; Jun 23, 2011 at 10:22 AM.
Old Jun 23, 2011, 03:47 PM
Professional heli wrecker
Luvmyhelis's Avatar
United States, WA, Spokane
Joined Oct 2010
4,172 Posts
Quote:
Originally Posted by OlliW View Post
just quickly two flight videos with the HH version of the gyromixer... no drift (well very minor drift), no bouncing, no break-out during full pitch...

unfortunately I still couldn't figure out of how to embeed videos here, hence again just links to the videos, sorry

http://www.olliw.eu/2011/ga250-fpkoa...23062011video1
http://www.olliw.eu/2011/ga250-fpkoa...23062011video2

(or for download http://www.olliw.eu/uploads/coax-gyr...-110623-wp.flv, http://www.olliw.eu/uploads/coax-gyr...-110623-wp.flv)
About the only thing that this forum seems to take are Youtube vids and one or two others. Aha! I spotted a blade strike! lol
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Old Jun 29, 2011, 01:12 PM
Professional heli wrecker
Luvmyhelis's Avatar
United States, WA, Spokane
Joined Oct 2010
4,172 Posts
I just spent quite a bit of time conversing back and forth with OlliW. We have reached an agreement since one of the boards to do the conversion is not available in the U.S. to have him program a few of them for me and send them over the pond, including one for E2. So I have some testing to do when they show up. For those following this kind of tech I am jacked! I am installing one of them in my fbl vtail brushless coax dual swash sk-360 version along with my two others. Then I am installing one in my 450 vtail brushless dual swash fbl custom build. So next month is going to be quite busy. I may be installing one also in one of E2's helis while I am at it if I can get my hands on the one he wants to play with in time. (hint, hint).

And (For the mods who seem to think he is promoting/selling something)
My sincere thanks to Olli for donating the time and effort in helping another enthusiast in building and programming these for me!
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Old Jul 02, 2011, 11:07 AM
OlliW
Joined Sep 2009
1,454 Posts
Hey LMH

any guess what the photos below could show?


Olli
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