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Jul 28, 2015, 08:12 AM
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Devo 7E Mod: Adding two 3-position switches

I finally got around to doing this.

The additional switches I got were Frsky spare parts from Hobby King: Here

(That blue switch you see in my photo below is a replacement for one of the stock Devo 7E switches which I broke sometime earlier because I was clumsy )

Before you even consider this mod, please note your 7E must have a recent build of Deviation firmware. If you are still on the stock firmware, or if you only installed the last "proper" release of Deviation 4.0.1, this mod is not likely to work. My own tx shown here was flashed with a recent nightly and a build by mwm for FrSky telemetry functionality. My blog entry for the CC2500 mod contains links to where you can download these builds, but I would advise that you try to use the most up-to-date builds as far as possible.

Parts Needed:
- some servo wire (or any other 3 color wire)... allow 20cm per switch and trim later
- 4pcs common signal diode (eg. 1N4148, 1N4004...etc)

Basic Steps:
1) Open up your TX

2) The 7E already has the holes in the plastic chassis for the 2 additional switches. However, these holes are covered by a thin decorative metal "sticker". You can either drill through this sticker, or remove them, which is what I did. To remove them, you have to loosen the nuts on the original existing switches, peel off the sticker and replace those switches.

3) Insert the 2 new switches, but don't solder anything just yet.

4) Remove the 5 screws on the bottom PCB and flip it upwards so you can see the LCD screen and fascia click buttons.

5) Solder 5 wires onto the indicated points on the lower PCB (refer to attached photo, which has clearly labeled each wire A-E). If, like me, you've removed the stock CYRF module, you can thread the wires through to the other side of the PCB via the rectangular hole under the LCD (also shown in the photo). Otherwise, you can just run the wires from the bottom edge.

6) Replace the bottom PCB and tighten the 5 screws for it.

7) Solder the diodes onto the new switches as per the photo. Note the diode orientation.

8) Bridge the center pins (pin 'D' in my photo) of each new switch with a short wire (about 10-12cm). You can take this wire from one of the 3-color/servo wires.

9) Solder the 5 wires from the lower PCB, matching the points as labelled on my photo.

10) Close up the Tx and boot it up in USB mode to edit the 'hardware.ini' file. This file must contain the line 'extra-switches=3x2' so that Deviation knows you've added these two switches.

That's it! The Devo 7E is ready for use
Last edited by straferr; Jul 28, 2015 at 10:23 AM.
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Jul 28, 2015, 09:48 AM
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Jul 28, 2015, 10:13 AM
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thanks, bios!
Aug 02, 2015, 02:01 AM
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Thanks Straferr! Excellent picture and instructions!
Aug 02, 2015, 10:17 AM
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Originally Posted by danbo98042
Thanks Straferr! Excellent picture and instructions!
Glad it helped, danbo Hope you enjoy your build as much as I do mine!
Feb 20, 2016, 09:06 AM
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um, what are they switches doing ?

i'm a dx6 g2 owner... sry for this question
Jun 17, 2016, 02:46 AM
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i've a problem

hey, firstly thx for this post
but i have a problem ... i use 1N4007
i rectified the line "extra-switches=3x2" in the program but the devo don't detect my 2 switches ...
my connections are good
pls help me !
Jun 23, 2016, 12:11 PM
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Switch ids
In the Devo 7E, is the left one identified as A0, A1, A2 and the right B0, B1, B2, in this order?
Sep 24, 2016, 01:34 AM
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Thanks for great info.
Attached is my Devo7E extra SW and special labels.
Works perfect!!!
Oct 09, 2016, 05:56 PM
Some Guy

Thanks for this post

I have performed the mod to my Devo7e successfully. I ran the wires around the edge, then brought them towards the center above the PCB. It worked very nicely. I used 1N4001s and the current (5.0.0) release.

As a Deviation noob I then had to figure out how to get that data out to my device, which I have done. MODEL1.ini is a straight 8ch with the three position switches on channels 7 and 8. MODEL2.ini is a 6 channel setup with the right-hand switches emulating a six-position switch on channel 5 for ardupilot, pixhawk etc. The 2 pos switch on the left hand is a rate modifier for the right stick. And the 3 pos switch on the left hand is channel 6.
Last edited by hyperlogos; Oct 18, 2016 at 11:05 PM.
May 22, 2017, 03:03 PM
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Just installed the 3 position switches (from but the Devo 7E is using them as a 2 position switch. Checked all the connections and they are good.

Hardware.ini has the 3x2 line in, and I can see both A0-2 and B0-2 switch. In the Model:Mixer menu, I tried changing channel 6 to the B0-2 switch, and it shows up. When I throw the switch, it is either at the top of the curve or at the bottom, there is no middle (third) position.

Might there be a change to the board, or Deviation?

NVM......found it........feel really silly....3 pages in complex....not 2........duh!
Last edited by UABMaddog; May 22, 2017 at 04:32 PM.
Aug 23, 2018, 05:04 PM
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I made the change with 2 SWITCH 3 positions. Where to find and how is it possible to modify the "hardware .ini" file?

thank you

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