ArduPilot/Copter Mega 6 position 'mode' switch for FlySky/Tunigy 9x/ and others.

After using this setup for as my 'mode' switch:































it worked OK :) 

But I decided to take it to next DIY level :)

There is 3 knobs on FlySky FS-TH9X radio, they are B5K potentiometers:

so we need to pick one of them that we going to replace with any available 6 position rotary switch.

(I have this one and it fits right)  
















Unsolder the 3  wires from B5K:

And remove the B5K from the radio :) 

Next we need to make a small array of resistors that will act as B5K pot, when we switch to different modes.

 The brown wire (  middle one on B5K ) feeds different voltage to the radio channel. 

Now we need to add the switch that will connect the brown wire to each position.

And now we have solid 6 modes switch for APM and ACM :) 


This is a "kitchen table setup" so if someone can measure better resistors value, pleas do :)

Its much easier than trying to setup some channels mix in this radio :)

Hope it was helpful.




Views: 16132

Comment by SilverFox on March 30, 2011 at 4:16pm
Looks like a nice mod, but the video is set to private.
Comment by ARHEXA on March 30, 2011 at 10:39pm

nice to see you made it.

actually this type of rotary switch in your picture is quite huge,

i dodn't get my transmitter yet, but i imagine it would never fit inside...

so i've searched for a much smaller rotary switch - should arrive soon.


how did you finally measure the pot value at each mode ?


and finally, how can I, with the serial monitor\terminal see the current selected mode ?

i'd like to tune the values while getting feedback at what exact value the 'switch' between modes is done.

that way i will set the rotary switch value to give out the middle value between two switching values, which will be the safest for not 'glitching' on to a 'near' mode.

Comment by ARHEXA on March 30, 2011 at 10:45pm

also, you could use any other 'total' value.

it can be anywhere between 5K and 50K without any problems, dont go down off 5K

i wouldn't go over 50K - maybe the detecting system needs the current....

you could set the total value as 10K, then easily guess your output, because it will be 'decimal'

i.e. 1500K after the ground will be 150 (out of 1000) etc...

Comment by Max Levine on March 31, 2011 at 7:49am
That switch is not huge, but yes its big :) Can you share some info about the smaller one ???
In ACM there is 'modes' option in 'setup' menu, it shows you switch position.

you can find the values here:

Yap, total can be more than 5K :)

Comment by Doug Weibel on April 1, 2011 at 12:46pm

Slightly off topic, but it IS possible with the stock Turnigy 9X firmware to program a mix using one of the 2 position switches and one of the three position switches to get 6 positions.  This is what many people do with other radios, but with the 9X it is pretty difficult to get the programming worked out to do it.  I did it once (after fooling around with it for many hours) and I think it required 3 mixes.  I don't have that programming any more and am wondering if anyone knows how to do it.


Please don't tell me to read the manual.  I don't speak Chinglish (no disrespect meant to anyone except the person who "translated" the manual), and the 9X firmware does not actually do what the manual says anyway....  

Comment by Doug Weibel on April 1, 2011 at 8:02pm
Ah, I wasted enough time to figure out how to do the programming again.... You can get 6 positions using one of the two positions switches and the three position switch. I like your mod, Max, but didn't want to go to the hardware trouble.

If anyone wants the programming, PM me.
Comment by Wessie on May 15, 2011 at 9:06am

Have you Read the following page?


It explains how to set 6 modes on the T9, JR9, and Futaba 9


Tested mine with the new Mission planner today, works great


Comment by Wessie on May 15, 2011 at 9:07am

But that Switch mod is also a really cool Idea if you have a radio with a knob. Nice!


Comment by Nick on May 15, 2011 at 9:08am
Can you do this modification to radios such as the DX6i?
Comment by Limebear (Rob) on May 21, 2011 at 1:56pm

Here's a repeat of the key information, because it can be quite hard to find:


If you want to have six modes, you'll probably have to configure your RC transmitter to do this. That's usually accomplished by mixing a two position switch and a three position switch on your transmitter.  Set your switch(es) to (ideally) produce PWM pulse widths of 1165, 1425, and 1815 microseconds or 1165, 1295, 1425, 1555, 1685, and 1815 milliseconds. (You can also do this with an analog dial, if you have one, but it's hard to reliably turn it to just the right position for six distinct settings). 

How can you know what the PWM pulse widths are?  Use the CLI to run the pwm test (AC2) or the Radio test (APM).




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