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Old Apr 04, 2010, 03:37 PM
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Joined Apr 2010
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Bare bones Tx/Rx ?

Superb thread, Kaptain

For a complete noob like me to anything Radio Control, who doesn't even have a transmitter/receiver, is there a more affordable, entry level, Tx/Rx than the Futaba? Would one of the Hobby King units work, I wonder, e.g.

http://www.hobbyking.com/hobbyking/s...x_%28Mode_1%29

Or, more specifically, will this unit work with your upcoming V4 software?

Thanks!
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Old Apr 04, 2010, 04:40 PM
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Man this thing is STABLE!!

Just did about 20 minutes worth of flying, on 3 packs....I can't tell you how well this thing is flying....VERY stable.

Kapteinkuk, if you ever integrate an accelerometer or GPS in your code, this will be the most stable Quad design on rcgroups!

On a 2500 LiPO, 35C pack (Rhino, from hobbyking) I can easily get a 5 ++ minute flight. I land early, cause I do not have an alarm on it yet, and the battery still has about 300-400ma lefts when I charge it again...very happy with the motors, and props so far.

I did some final trimming today with the TX, and I can easily hover this thing almost hands off...obviously, I need to keep on the throttle (but that is why we need GPS!! :-) )

Rolf, again THANK YOU SO MUCH for your code!! You wrote a VERY GOOD set instructions for the Atmel chip, and it is doing an EXCELLENT job at flying my quad!

I will have more video soon for you all....need to convince the wife again to take it!
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Last edited by cyborgcnc; Apr 04, 2010 at 05:39 PM.
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Old Apr 04, 2010, 09:19 PM
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By your first picture it is correct sequence if you have the probes hooked up as

0-aileron
1-elev
2-throt
3-rudd
4-aux

in the second picture if ch1 aileron channel, ch3 throttle channel and ch5 aux channel then it seems correct

Quote:
Originally Posted by thanhTran View Post
Thanks. I understand how the quad calculate the channels from the 3 odd channels it uses.

I believe the sequence of the channels is correct. At this time I could only look at 5 channels, but they are in sequence. Please see the attached photos for the channels capture. They seem to be in correct sequence, right?

One of the weird things is that with this Eclipse 7 & Spektrum RF & RX set up, when the board is armed, the thing works: so the sequence seems correct because all 4 motors (which I hooked 4 servos to watch) move in response with the TX control. I.e. if you move throttle up, all 4 servos move up, when you move rudder or pitch or roll, some servos move right some servos move left.

Thanks

-Thanh
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Old Apr 04, 2010, 10:13 PM
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Joined Jul 2008
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Quote:
Originally Posted by thanhTran View Post
Hi Kapteinkuk

I've been watching this thread with great interest. I loved the flying chicken so much and the simplicity of your project that I decided to duplicate your great work.
So I got the PCB done & programmed. However, I got some weird issues with the arming of the controller. I'm using your V3 software in a somewhat modified V3 (i.e I'm using a voltage reference chip instead of the LM317)

My TX is a Hitec Eclipse 7. The actual radio RF module can be replaced by either the stock Specktra module or the modified original Specktrum DX6 TX. With the original Specktra module and an old Berg6 RX, the quad controller is armed immediately no matter what position of the throttle stick, and I can see the servos hooked to the Motor connectors moved with my throttle stick movement. However, when I use the DX6 RF Tx module in my Eclipse 7 and a AR6000 RX, the quad controller just does not arm no matter what throttle stick position is.

Before I built the quad, I've verified that my TX with the Spektrum RF and an AR6000 have sequence channels with a logic analyzer (sump.org with a BusPrivate V2). I've also compared the signals of Ch1, Ch3, Ch5 of both RF module and RX setups, they are basically almost identical down to micro seconds.

During live poking with the logic analyzer, sometimes somehow the controller got armed with this Eclipse7 Spektrum set up, and I got servo movement as expected.
I've checked the signal level of both RX'es, they are both around 3.29v.

I'm running out of idea of what causes this. Any suggestion? I'm thinking about hooking a ttl uart to the PD6 to see what you have for debug there, but I'm thinking about asking the expert first. Any suggestions?

Thanks Kaptein!

-Thanh
Hitec uses the samme channel ordering as Futaba. But Im not sure what the problem is. If you connect a terminal to PD6 and enable the debug code you can get the channels as seen by the atmega.
Also you can try the new V4.
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Old Apr 04, 2010, 10:15 PM
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Joined Jul 2008
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Quote:
Originally Posted by dd016857 View Post
Kapteinkuk ,...just an idea..... While you are busy writing a new version of the software I wish to know if an accelerometer can be incoperated in the existing design? Would it improve hovering perhaps?

As others have stated too, I am very appreciative in your design and effort presented here.
Rolf...thank you very much.
Thanks
This controller will be as is. But maybe I will make a new controller with all the gadgets. Time will show
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Old Apr 04, 2010, 10:18 PM
Quad Whisperer
Joined Jul 2008
942 Posts
Quote:
Originally Posted by jjbunn View Post
Superb thread, Kaptain

For a complete noob like me to anything Radio Control, who doesn't even have a transmitter/receiver, is there a more affordable, entry level, Tx/Rx than the Futaba? Would one of the Hobby King units work, I wonder, e.g.

http://www.hobbyking.com/hobbyking/s...x_%28Mode_1%29

Or, more specifically, will this unit work with your upcoming V4 software?

Thanks!
Any reciever will work with the V4
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Old Apr 04, 2010, 10:20 PM
Quad Whisperer
Joined Jul 2008
942 Posts
Quote:
Originally Posted by cyborgcnc View Post
Man this thing is STABLE!!

Just did about 20 minutes worth of flying, on 3 packs....I can't tell you how well this thing is flying....VERY stable.

Kapteinkuk, if you ever integrate an accelerometer or GPS in your code, this will be the most stable Quad design on rcgroups!

On a 2500 LiPO, 35C pack (Rhino, from hobbyking) I can easily get a 5 ++ minute flight. I land early, cause I do not have an alarm on it yet, and the battery still has about 300-400ma lefts when I charge it again...very happy with the motors, and props so far.

I did some final trimming today with the TX, and I can easily hover this thing almost hands off...obviously, I need to keep on the throttle (but that is why we need GPS!! :-) )

Rolf, again THANK YOU SO MUCH for your code!! You wrote a VERY GOOD set instructions for the Atmel chip, and it is doing an EXCELLENT job at flying my quad!

I will have more video soon for you all....need to convince the wife again to take it!

Thank you very much!

This controller will stay as is. Maybe one day a new controller with all the gadgets!
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Old Apr 04, 2010, 10:40 PM
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Joined Jul 2008
942 Posts
I think I have busted a few brain cells, but here is the new V4

The good news:

- Works with any 4 channel or more reciever. Any channel order.
- Higher control loop frequency, 160Hz, much more stable.

One drawback is hardware changes:

- Reciever connect to different pins than V3. It had to be done to use the external interrupts.
- Had to add 3 capacitors to act as gyro filters. (forming a RC filter with the 6800 Ohm resistor on the gyro boards) My software filter did not perform good enough due to slow hardware.

I tested it on my smallest quad, which was a bit unstable. Now I could double the gain without oscillations and it is rock stable!

Video will follow.
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Old Apr 05, 2010, 12:28 AM
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Excellent once again.

And the hardware changes are minor to what I was expecting. Now the students will be able to use a cheap radio and keep their hands off my good one.
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Old Apr 05, 2010, 01:12 AM
That tree again!!!!
thanhTran's Avatar
Germantown, MD, US
Joined Sep 2004
6,642 Posts
Quote:
Originally Posted by pug398 View Post
By your first picture it is correct sequence if you have the probes hooked up as

0-aileron
1-elev
2-throt
3-rudd
4-aux

in the second picture if ch1 aileron channel, ch3 throttle channel and ch5 aux channel then it seems correct

Thanks Pug!
Yes, that was how I hooked the logic analyzer to the receiver. I
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Old Apr 05, 2010, 01:22 AM
That tree again!!!!
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Germantown, MD, US
Joined Sep 2004
6,642 Posts
Quote:
Originally Posted by kapteinkuk View Post
Hitec uses the samme channel ordering as Futaba. But Im not sure what the problem is. If you connect a terminal to PD6 and enable the debug code you can get the channels as seen by the atmega.
Also you can try the new V4.
Here is what the debug says when I un-commented the "rcall ShowChannels"

With Berg6 RX: 0005 0013 0003 0017 0035
With spektrum: 000B 0019 0006 0019 0037

They look almost identical. The reading of channel 3 varies from 0003+ - 005C+ for both receivers when I move the throttle stick. I'm trying to debug the code with AVRStudio. Sometimes, during single stepping, the board armed correctly. I'm not familiar with AVR assembly. Not just assembly alone, your math library is so advance to me, and I just couldn't figure out some of the codes there

ldi t,high(int(@1+0x8000)-0x8000)
...
ldi t,high(int(frac(@1)*0x10000+0x10000)-0x10000)

Apart from thinking you are trying to get the integer and fraction part of the numbers, what do they actually do? What do we get when we add the second param (says, 20, or 100) to 0x8000 and then substract with 0x8000? And why 8000 and 10000?

anyway, I'm going to try out your V4. Thanks very much

-Thanh
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Old Apr 05, 2010, 01:50 AM
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Joined Mar 2010
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great job kapteinkuk

thanks alot


v4 is working with my Tx/Rx, slight trim is required , when i increase the throttle m1 starts first , i think i need to decrease the yaw gain .. soon i will put video of the flight
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Old Apr 05, 2010, 02:28 AM
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Joined Mar 2010
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when i give the throttle m1 and m4 starts first and m3 last by m2 , i tried the trick gave by cyborgcnc i couldn't make it right please guide me the tuning in detail

2204 brushless outrunner
10A esc (not programmable)
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Old Apr 05, 2010, 02:38 AM
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Joined Mar 2010
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My gui for avrdude programmer still gives an error:

clocktest : 1 unrecognized caracter: ":"

WHAT MUST I DO?

Thanks Lowie
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Old Apr 05, 2010, 04:51 AM
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Ourense, Spain
Joined Nov 2005
48 Posts
Thanks a lot kaptainkuk for the V4, now it can be used for all the people.
Thanks a lot for your job.
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