Burt's Devo 7e 4-in-1 Transmitter Module mod


Here’s another journal, a bit tidier than my previous (build) journal. I hope it will be a more concise version of this original thread by HappyHarry:


First I stripped the new 4-in-1 module of pins, clearing the via holes with the “tap” method of knocking the board on the edge of my table after softening the solder.

This is after removing the original transmitter module. I tinned the pads and alcohol swabbed the entire area.

I stripped and tinned the wires I was going to use. Digikey was, once again my friend, getting me 30AWG stranded wires from Adafruit in multiple colors. I also got to know how bitchin’ my Irwin Vise-Grip wire strippers are.

Laid in the first set of wires, according to this more straightforward diagram:

Flipped the board over and soldered the first set of wires. This pic is after the second set, with three strands; one for a different transmitter… the fourth was built in, connected by the first set of wires (I think).

Next, the Big Deal, the reason I’d been so apprehensive of this mod. In order to enable one of the four modules, you have to solder directly to pin 50 of the main chip. This is a pic of me isolating that pin using Kapton tape, per technique described by Silpstream.

NOTE: A reason I did this mod first was because the additional mods (here and here) that I’m keen on doing require an upgraded CPU with more memory, per another recipe by Silpstream. Given the fact that I’d likely remove this CPU, I figured I’d use it as my trial run for soldering directly to a pin. The other mods will require this pin, and two others, to be soldered to directly.

Here’s the result after all the soldered wires. After this, my green wire connected to the chip came undone. It took four more tries to get it nice and clean.

…and a broader view of the project thus far.

Next is attaching the upgraded antenna. This 4-in-1 mod include a range mod that previously was a separate project. The pigtail and dipole were both from the original how-to by HappyHarry (here).

I used my finger to measure how deep the RP-SMA Female socket went into the original antenna housing.

Then, one of my favorite tools, this hobby saw, made quick work of the housing.

I installed the pigtail into the housing…

… then attached the antenna to the 4-in-1 module, snaked it inside the case, then up into the housing.

Here’s the case reassembled with bootup screen. This is showing a now out-of-date version of DeviationTx, the latest full release, v5.0.0.

The hardware’s done. I’ve got to finish the software side of things next.

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Wow, @burtlo! You tackled the 4-in-1 RF module upgrade! :sunglasses:

That’s a lot of tiny little wires. Didn’t realize you had to de-pin the module. Somehow, I mistakenly assumed that the pins would just plug into the insides of the Devo 7e. How naive of me. :confounded:

Really appreciate your effort to condense info from various sources into this one thread here on MMC! Bookmarked for when I get the courage to do it myself. :wink:


The trickiest part is removing the original module without ripping the pads off! ( I did. But I fixed it.) Make sure to very slowly pry off the original module! Its a great mod though! Good job!


Impressive work sir! Big thumbs up!


Haha nice!
That one pin took me 20 minutes to solder lol.
IMO this is the best Devo 7E mod.


I’m enjoying it myself… bound a number of toys to it, though some are experiencing more drift than I recall them having with their stock transmitters.

Overall, though, one helluva mod… so much capability in one go.

Like I said above, I’m keen on doing the processor upgrade as I’d like to have the experience of adding the 3-way switches and pots, primarily to practice PID tuning in flight. Any experience/comment/opinions on that?


Haven’t tried that one yet. I will once I can get my hands on a heat gun though :wink:


Calibrate your sticks in the devo.
drift will be gone.
do this when you notice all quads drifting.

3 way switches are great.


@TheMadCADer: Good to see you here! I was just telling people about your Quark 130 micro v-tail recently. Still hoping for a 4" Quark myself. :wink:


yes, of course! thanks for the simple reminder, @tronaton!


Haha good to see you too!
I’ve retired from designing frames for a while (too many other projects), but if you want, I can pm you the files if you’d like to modify them.


LOL, @TheMadCADer! “Too many other projects” is a familiar challenge. :smirk:

Appreciate your offer of the files. Would be a steep learning curve for me, with CAD and all. But I might take you up on it, if I can ever manage to work through my backlog of (standard x-quad) builds. A 4" Quark might make a good travel combo with a 4-in-1 RF modded Devo 7e. :smiley:


No problem, just lmk :wink:


Replacing STM32F1s is pretty easy once you get the hang of it.

Step one is getting the old one off… this is easy… put flux all around the board.
(I use liquid RMA flux that comes in a pen.) Set your hot air gun to 280C or thereabouts and start heating up the chip…

Step 2 is making sure you get rid of all the shitty lead free solder on the pads… use some solder wick and clean them up.

Now… Flux everything really well again.
Set the new chip in place.

Now here is the trick: get a tiny, tiny amount of solder on your iron, and solder one pin on one corner of the chip.

Is everything nice and lined up? You can push the board around a tiny bit to get things nice and lined up… now solder another corner down. Once I have the corners tacked down, I just go from pin to pin, working my way around the board. I have a small chisel shaped tip on my iron. I can solder two pins at a time by getting a tiny amount of solder on the iron, and touching the feet of the two pins.

If you are having issues with bridging, use more flux, clean your tip, and try dragging the excess off the pins. Use some solder braid if necessary.

Try removing and re-adding the same chip from a dead flight controller for practice.


This is what I’m looking forward to with my hot air… watch starting at 3m00s:


Wait a minute, @burtlo! I totally missed that. You can upgrade the processor on the Devo 7e?!? :astonished:



I figured out the order of operations to be this:


…then this (with this STM32F103RET6, the larger of the two processors suggested):


…then this:


…then this:



I thought about doing these mods but went with a Taranis to satisfy my switch and knob lust (and got voice as a bonus).
I’m going to see how it goes for you and may yet treat my trusty Devo7e to the full monty mod.


I went the other way… eager to solder stuff, I planned this, and then got a Taranis X7 recently… just waiting on modules.


If he goes all the way with this mod, there is a voice option too for a few bucks and some more soldering.