7e with OpenPilot OPLink (PPM) out and DeviationTX

For quite some time now I have not trusted the Turnigy 9X line of Transmitters. I have been looking for an inexpensive yet hackable alternative. The DeviationTX firmware update scene closely mimics that of the 9x crowd. 
 
www.deviationtx.com
 
Of the supported models - Includes support for DEVO 6/6S/7e/8/8S/10/12/12S the 7e seems to be right at a sweet spot in functionality and price point. It (just as the other more expensive variants) can be modded for example with an nRF24L01 or one of two other chips and given the ability to support 100's of small "nano drones" that novelty shops have been putting out the past few years. 
 
www.hacksmods.com/2013/05/nrf24l01-devo7e-pinout
 
Although there are range increase tutorials that feature removing a diode, I wanted to increase the range in a method I was more comfortable with. I wanted to use the 433mhz OPLink! 
 
www.hacksmods.com/2013/04/walkera-devo-7...-increase-range-mod/
 
I knew that the DeviationTX firmware supports PPM out via the Trainer port as I have used it with various simulator packages. I wanted to do a quick sanity check to verify that the PPM out was compatible with OpenPilot boards. I simply hard wired it to pin one on the RX port of an Atom, which worked out great. The TX Wizard recognized it just fine. 
 

 
The next step was taking this setup internal... we did a quick test using the Trainer port


To go all in first we need Ground (green) and + (Yellow)

 
Next the tip and sleeve signals need to be sorted out. 

 
Keep in mind that Black == Tip and pins two and three are the Sleeve... in order for tip to activate both sleeve pins must be pulled to ground. 
 

 
Shrink her up! 

 

 
Add a little fire... 

 
Shrinkage, it isn't ALWAYS bad. 

 
Plotting on placement

 
Time for 3m Clear VHB tape! 

 
This should do nicely.

 
Do a quick sanity check on the Tip pin at powerup before sealing... (noticed I used the main port instead of Flexi! Swapped to Flexi port!)

 
At this point I made sure the PPM connectivity was all setup in the firmware, and functioning in the GCS, then I sealed her up!  http://wiki.openpilot.org/pages/viewpage.action?pageId=20742418
 
All sealed up and the antenna pushed through the mystery hole / flap. 

 
Add a finishing touch to make sure I recall they are a pair... 

 
Set to 7 channel PPM and rock out! 
 

Enjoy!

Here is a link to this topic on the OpenPilot forum - forums.openpilot.org/topic/50045-walkera...ut-and-deviation-tx/

Great tutorial kfinisterre!

FYI, if the 7e is the same as the 8s and 10 that I have, the PPM port is also a UART, so it can support digital control (as opposed to PPM) and telemetry. I should still have a (old) patch to the Deviation and OP firmwares to support sending the stick position over a serial link. My plan was to also add telemetry, but I haven't gotten to that yet. There's really not much benefit to sending the stick values digitally, other than a slight decrease in latency and a bit more accuracy, but telemetry would be useful.

BTW, this is Brian from OP...

Brain nice to hear from you! I wanted to look into using the second port (main port) as a means of updating the TX screen with flight data.

I am not familiar enough with the Deviation code to quite figure out where to start.

Obviously we would need a UAVTalk parser running on the Deviation side of the house. The other alternative would be to write custom OPLink firmware specifcally for exporting data that was more appropriate to the Telemetry Menu. Perhaps one would also need a *new* telemetry menu to make it OpenPilot aware.

Nice to hear from you dude! Been wondering about ya. *cheers*

You shouldn't need to hook into the main port. Ether the Flexi port could be configured for PPM up and telemetry down, and serial both ways (my preference).

I think a custom OP module for sending a simplified telemetry down would be the way to go. The Deviation firmware supports telemetry for some other radio protocols, so emulating one of those would be easiest. You would also want to make it fairly low data rate so that it wouldn't reduce range.

BTW, I've been playing with some new hardware designs that you can see a bit of on my blog . I've got some more to add to it, but I've been busy lately and haven't added it. I have a OPLink-like board that goes with the flight controller, and a new module that I built for my Tx that includes an RFM23BP and nRF51822, which adds nRF24l01 and Bluetooth low-energy. This would allow e.g. direct logging of telemetry to a PC/Tablet/Phone.

kfinisterre wrote: Enjoy!

Here is a link to this topic on the OpenPilot forum - forums.openpilot.org/topic/50045-walkera...ut-and-deviation-tx/

Thanks for this useful information. however, pictures are no mot displayed. could you provide again information about your connection ?

I try to use an oplink mini on my Devo7 (not 7e). (I did not know before that this walkera device do to communicate with oplink mini ...)
I plugged the oplink mini supply without step down module but directly on 5*1.2v . it is well powered. is it ok ?
I plug the mono jack on DSC port of the transmitter. Do you have to use the tip of the mono jack connector ? how to check that signal is well passing ? I connected to the 4th cable of JST SH conector.
Should I physically remove the original antenna of the transmitter?

thanks for help

ppm out from deviation should work fine, normally indeed the 3.5mm the back is ground and I believe the tip is ppm out, can't remember.

You should nor remove the antenna, but if you create a model with ppm selected there should not be RF radiated.

Hello all,

For the record, yes it works! I had to remake the Oplink mini configuration :
librepilot.atlassian.net/wiki/spaces/LPD...linkforRemotecontrol
section "Telemetry + Remote Control + Bluetooth" as if i had a bluetooth transmitter too.

see how does it looks in picture.

It worked for few tests. Now i have no signal detected anymore but it should be something else.

Hello futur reader.

For the record, i added a BT transmistter on my GCS, I made again the vehicule cabling, and reconfigured the CC3D. It is flying now ! thanks PPM

astoningshingly, BT transmitter on my GCS opling hekp to stabilise the connections. it seems to have less disconnection. may be common ground, or voltage stabilisation ?