Adding Telemetry to the Walkera QR X350 Pro



Hi Drone tech,

Is that it then? Have you actually got full over the air duplex telemetry on the QR x350 Pro? Any chance you’d be able to grab a video for us of it working?




Yes, I absolutely have full duplex telemetry working on the Devo-M. I have performed follow me and sent point to point missions plus OSD working.


Yes, I can take a video of the Devo-M connecting to Mission Planner through the telemetry modules.


Brilliant! I’d love to see if possible :slight_smile:


My setup from the DEVO-M to the 3dr has a tx-rx setup hard wired to board boards (cut the wrong end of the cable - twice) it works one way, now I want the duplex like you have. Do I put the 1k on the devo tx or the 3dr tx. What does it exactly do.


Follow the directions at the top of this page about what resistor to change. UnmannedTech’s directions are confirmed to work if you replace the resistor next to the MEGA32U2 chip! Look at the picture dated Sep 15th above. It has the resistor circled in white next to the Mega32U2 chip. Change that resistor to a 1k ohm. Then add a standard non SMD, legged resistor between the TX pad and the TX wire going to the telemetry module. But if you follow the directions at the top of this page you will get telemetry working. You will need a very fine tip soldering iron and a magnifying glass held by a 3rd arm/helping hands device. If you want to contact me with Facebook Messenger - look me up on Facebook and send me a message. My name is Shane Carles and you can find me there. We can get on Messenger phone service and I can talk you through getting the mod done correctly is you can do the solder work without damaging the Devo-M.


I’m doing the resistor mod for anyone that can’t do the solder work. I have done over 10 so far and all of them are working as intended. Full duplex telemetry on the Devo-M. But there are no guarantees on the work due to the nature of how small the resistors are. I have all of the necessary equipment though and that increases the rate of success. I’m also adding the 4 wires to the Devo-M that is needed to connect to the air module. Anyone that wants this done will need to remove the Devo-M, pack it and ship it to me. You will also need to pay for return shipping. Contact me (Shane Carles) on Facebook for the details.


I’m upgrading my x350pro flight controller to a pure apm 2.6. The devo-m had some specific limitations I need to avoid for search and rescue use.

I am selling my devo-m (2 week old). It comes with the 915mhz site and ground module pre-soldered. I can confirm as can drone tech that I have 2 way telemetry on pc and android devices using mission Planner (pc) and Droid Planner.

I removed the 0ohm resister so you can communicate 2 way, works great in the air. I will include 5 x 1k smb resistors to get the usb and radio working together.

I’m asking $200 for everything, plus shipping. Email me our PayPal to


Just finished this Mod today, bidirectional is working perfectly, I don’t even need to do the control-t. Just connect, and it it downloads the params. Same as being connected via USB.


Very good. You are now part or a very small community of people that have full duplex telemetry from the Devo-M.


DroneTech. Can you put an outline of the position of the resistance ?.

I am a beginner and I need something easier the explanation.

Thank you very much.


The pictures at the top of the page shows where to put the resistors.



Only to understand well.

  1. I will change the resistor to 1k like the pic in the top of page

2)About 680ohm. I have to change it or not?

3)About TX and RX on DEVO M, is the pic below right? So the TX is the BLU wire while the RX is the yellow one? In an other pic the two wires are inverted.

Please let me know. thank you



Hi unmannedtech
did your module still avalaible?
I’m new on this, but I’m curious to try all before I crash on the floor :slight_smile:


After a lost control flight and some damage I rebuilt my X350Pro. I have a few issues that maybe someone can help. When running mission planner I notice when it reaches its first waypoint that it tends to drift a good distance before going to the next. Then when it comes to landing it does not want to turn off and the motors go a bit crazy, even if I switch to manual control?

Also does anyone notice their motors are very warm after a flight? Compared to my phantoms they are at least twice as hot?

What Version software is everyone using at this point with the telemetry and mission planner?


The unique part of the 350Pro is that the Devo-M can be modified to work wirelessly in both directions with the Mission Planner software. For it to work correctly some very specific soldering need to be done and a replacement of very small resistors. Shane Carles is the person I met and he is offering to do this at a reasonable price. You can contact him at you will need to send him your Devo-M and the 3D telemetry modules which you can find here:

Grandpa Jake


Ok I managed to get full duplex working (So two way telemetry) by only removing the 0 ohm resistor

Once this was removed (I just pushed it aside so there was no contact any more so I could revert it easy) USB stopped working for two way but started working for CP2101

Hope that helps :smile:



I’m currently attempting to add a minim or mavlink osd, (whichever works, i have both. Currently the mavlink as it seems to work better, but it is also possible the minim is damaged) to a qr x350 pro. I have it connected and almost working. I have video, and osd overlay, but the data does not update as it should. Only flightmode will update reliably on the osd. The rest mostly stays at at zero. If i connet to mission planner using usb, i can get the osd to update properly(or very close to it, i cant be 100% sure). Im not sure if i can make it last in flight, but either way this is not a viable solution as i’m not using missionplanner in the field. I just want the osd… :smile:

I have it connected like this:
devo-m rx —> osd rx
devo-m gnd—> osd gnd
devo-m 5v* —> osd 5v. (*5v from the component right above to the RX label on devo-m, according to the pic in this thread)

I have bridged the two sides on the osd, running both digital and analog side directly from devo-m 5v. Video is connected using only ground and vin+vout on the analog side.

I have not touched any resistors or done any other modifications. There is much back and forth about those in this threat and frankly my head is spinning a little :grin:

Is resistor mod needed for OSD to function properly, or is that only for two way communication? ( i need only one way for osd, right?)

edit: works fully now, but only after rc transmitter is turned on. Did try the “enable telemetry” button in mission planner, but its unclear to me if that button does anything as theres no feedback. Also altered some sr0 parameters. either of those could be it, Or, it could have been working all along, and i just didnt turn on the transmitter… running firmware 1.7 for devo-m, downloaded from, in case that is relevant.


I think the firmware in the Devo-M will not complete initialize without radio input


I need a link for the resistor I need for mod please