I got a 2.4" screen today (but not yet the development board). While it is smaller than the opening in the Devo7, I think it'll work ok. Has anyone ever figured out if it is possible to fully disassemble a Devo7 (or WK2601/2801/Devo10) and separate the bezel? There is a standoff behind the plastic (where the screen goes) that appears to be held on with 6 screws. 5 of them are accessible from the back, but one appears to be driven from the front underneath the bezel. I think the bezel is fused to the transmitter body; at least I haven't yet figured out a way to fully disassemble it and remove the standoff. I may end up cutting it out, but I thought I'd check if anyone has any insight.

Originally Posted by Kerbob

- Can't see the screen in the sun hardly. Better contrast scheme may be a good fix here.

http://rc.fdr.hu/devo.php#cust_lib

I have extracted the "standoff". First you need to retire the screws. There is one that you can't retire because it seems to be inverted. It seems like it arrives from the front of the transmitter, but I have been unable to find how to access to the head of this screw.

Well, when you have all the screws removed (minus the screw that is inverted). Then with the finger press the transparent plastic with some force until it separates from the "standoff" (it is not necessary to full retire it, only at the borders of the "standoff"). After that, the "standoff" is able to separate from the body . With a screwdriver, force the "standoff" at the place of the screw that is inverted till the "standoff" get out. Be aware to try to don't mark the transparent plastic or break the "standoff". You need to make force to extract the "standoff" from the screw. Be aware because the "standoff" could break. I got mine out, without problem but you need to be careful to get it out.

thanks. I didn't realize the clear shield was glued to the standoff. It turns out that if you remove the gimbals and the horizontal trim switches, the fornt bezel will come off exposing that last screw. If you fully remove the clear shield, you'll find that the opening is almost exactly the size of a 2.8" lcd screen.
it needs a small amount of trimming, and then a 2.8" screen will fit right in. Assuming you're going to cut the clear plastic anyway to allow for a touch interface, this may be the way to go.

You can find the raw screens on ebay (these have a builtin driver, but require a 16bit interface to the mcu) which require soldering.

The $11 2.4" board I got is nicer as it only needs an 8-bit interface, and has a builtin SD card for storage.

Here's an image where I've fit the screen from my STM32F103RBT6 development board. As I've said before, that board is not very suitable, but the module (which is similar but not the same as this) would probably work fine:
http://www.ebay.com/itm/2-8-inch-TFT...item3a788f5e44

Looks good....should replace 'Devention' label?

Wouldn't be hard to remake one using half hour epoxy, 5 min goes yellow.
Print Logo and cut final shape.
Surface tension of the epoxy could with little luck make it nice and curved.

You have found the head of the screw . Yes, a 2.8" has the exact size for the hole, but seems like it is needed to cut a little of the case to insert it. A touch screen seems to be a valid option and probably the best option because you can construct a module that is full independent of the number of buttons that the transmitters have. The module could work alone, and to be incorporated in whatever transmitter.

The problem is with the number of I/O. You need:

8 digital inputs for the digital trims or if the radio has analog trims, then 4 analog inputs.
4 analog inputs for the sticks.
1 digital input for the power switch.
6 digital inputs for the buttons at the screen.
1 analog input for the potentiometer.
For the switches. There are two switches with two positions, so 2 digital inputs. There are three switches with three positions, so 6 digital inputs. A total of 8 digital inputs.

So finally you need 8+1+6+8=23 digital inputs, and 5 analog inputs.

Also you need the I/O to control the RF module and the sound. Also you need the I/O to control the screen and if you want, the touch screen and the SD.

The problem with the bigger screens is that usually they are controlled with 16 data lines, the small screens can be controlled by SPI that need less lines. A minimun of 23+16=39 digital lines, plus control of the screen ¿?, SD ¿3?, touch ¿3?, RF ¿3? and sound ¿1?.

Really is needed a big number of I/O lines if you want a generic main board. Other option is to use a buffer for read the inputs, or to use and IC for the A/D but then you need to build your own main board.

The screen that you proposes sounds OK.

3.3V power supply
Touch Screen Interface: SPI
16 data lines.

RS, WR, RD for control the screen.
RESET for the reset.
BLCNT for the back light.
TP_SI, TP_SO, TP_IRQ, TP_SCK for control the touch pad.

It is 16 data lines, 3 control lines, plus RESET and BLCNT. 21 lines for control the screen.

It is 4 lines for control the touch pad.

A total amount of 25 lines for control the touch screen and 3.3v that allows to connect directly to the microcontroller.

Originally Posted by Tripert

A total amount of 25 lines for control the touch screen and 3.3v that allows to connect directly to the microcontroller.

Right. this i the problem. The board I have right now supports an 8-bit interface along with the 16bit one (though I'm not sure I can make it work with the FSMC controller).
The devo8 and 10 (probably all) use a matrix such that you can read 20 digital inputs with 9 controls (4 rows + 5 columns = 20 switches). It is possible to do the same, but it requires a lot of annoying wiring.
As you mentioned, it would also be possible to program the devo7 to work as a slave for I/O. This would greatly simplify the amount of wiring needed, but would not help support the WK2x0x models.

On devo 7 could be used the transmitter as slave, and in the other transmitters, could be used something similar to that (but with other microcontroller like ARM, etc):

http://www.ebay.com/itm/Micro-Contro...item41662ea17a

That is, use another very simple board with many I/O, working only for the I/O and as slave. The same thing like in Devo 7.

Is it possible to add flysky support without opening the TX (using the trainer port, magic cube mod maybe...)?

Originally Posted by PurpleShark

Is it possible to add flysky support without opening the TX (using the trainer port, magic cube mod maybe...)?

Sure. It requires a UART->SPI converter and to rebuild the protocol code for a standalone module. Something like a Teensy 3.0 would make pretty easy work of it.
But as I've said before, I'm not particularly interested in building such a thing, so someone else with the hardware skills will have to step up to build it if it ever gets done.

OK I got lost in the scope of posts. I have 2 Q?

1. So at this time the Devo7E only has its size going for it for small hand people like me? I was looking at a Devo 10 when I ran across the 7E.

I have Walkera Super FP(out side bird) and getting a Blade MSR (for inside bird), looking at branching into Solo Pro 228P (outside) maybe a Trex 100X (for inside) more down the road.

Looking at a tx I can fly them all with. Super FP and MSR, I know with a Devo 10 and firmware update I can fly them with no soldering. How about the Solo Pro? I know the Trex100X I need to cut my extra 9958 tx apart.
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2. Not to sound like a crank. I'm first getting into this stage of the game and it seams like people aleady at the advanced piont think we all know the protocall and tx stuff and manufactures don't post so its layman understandable, and never talk about the basics or if they do its super super basic like " Includes 1 transmitter" . .

Maybe some where post a list on heli brands/makes by protocalls-bindable cross overs. Ever serach the web for that?? Thats a lost cause.

Like they do for car parts and other hobbies/sports.

Can you help this old dumby please? I don't have a deg. in electronics and never got into electronics growing up, I was always a car guy.
New to the the RC gig.

Originally Posted by Rich Knapp

OK I got lost in the scope of posts. I have 2 Q?

1. So at this time the Devo7E only has its size going for it for small hand people like me? I was looking at a Devo 10 when I ran across the 7E.

It depends on what you mean. Purely from a cost perspective, the Devo7e is much cheaper than the Devo10. If you don't need many analog controls, it should be a perfectly fine Tx. If I had to choose between a Devo7 and Devo7e, I'd almsot certainly take a 7e at this point. If you are willing to pay for the Devo10, it is definitely a better Tx. If you are interested in using Deviaton to fly all of your models with one Tx, then the 7e is not yet supported so your only options are a Devo6s, Devo8s, or Devo10 (telemetry is required to support SoloPro models). you'll be able to fly SoloPro, DSM2, and all Walkera models with Deviation on any of those Tx.

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Maybe some where post a list on heli brands/makes by protocalls-bindable cross overs. Ever serach the web for that?? Thats a lost cause.

I'd love to see this too.
Walkera basically has:
Devo - current protocol used in all their new helis
2801/2601/2401 - their older 8/6/4 channel protocol. I don't have a definitive list, but any rx labeled as 'Rx2x0x' (where 'x' is a number) and there is no 'D' at the end is likely to be supported by these protocols
DSM2: Spektrum, JR, Blade helis use DSM2/DSMx (Deviation only supports DSM2 at this point)
J6Pro: Any SoloPro model compatible with a 'J6Pro' transmitter. Many of the older 4ch helis are NOT compatible.
Turnigy: Compatible with Turnigy/Flysky 8/9ch transmitters (i.e. the '9x'). Also WLToys v911/929/939 and the Xieda 9958 (needs add-on module)
HubsanX4: Compatoble with the Hubsan X4 quad. (needs add on module)

That isn't comprehensive, but should be a reasonable start.

Thank you very much. Looks like my best bet is the Devo 10. In my budget and 8 is a little much for me and the type flying I'll be doing.

What I do know.

Super FP came with a 2402D (devo tx)
MSR is DSM2
I'll just have to check on the Solo Pro's I'm looking at.

Devo 10 here I come.

Anyone using a Devo with an iKon fbl controller per chance? I have it mostly set up but am confused on what to do about the gyro channel. Should it be on 5?