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:

3689397360?profile=originalAnd 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.




E-mail me when people leave their comments –

You need to be a member of diydrones to add comments!

Join diydrones


  • I just finished this mod on a Turnigy 9XR. I made a few changes though, I used a twelve position switch instead of a six, this has a few advantages. You get 12 modes obviously, but you also, if you set the control nob up properly, can tell which mode your in as though your telling the time which I thought was handy. I'm not sure how the autopilot will behave yet but I'm sure I will be able to set it up to recognise the first six modes as normal and treat the last six as the sixth mode for now. I did read somewhere that there is an intention to increase the number of flight modes on ArduPilot.  Hopefully a twelve mode switch is future proof. 

    If anyone want the RS part number for the switch I used give me a shout I will dig it out, it was an expensive switch though. It fits straight in a 9XR with no chopping about to do and its continuous rotation so you could go from mode twelve to mode one if you wanted to. 

    Last thing, I set up an X-Gyro 1000 head tracker on the 9XR without using an external battery. If you've got a 9XR and your thinking about doing this, there are a couple of things you should know first. The Futaba trainer socket on the 9XR is PPM out only, Pin 6 (PPM input) is not connected!  You can only get PPM in via the JR socket.

    I used the Futaba socket 12v supply for the X-Gyro and the JR socket to inject the PPM. You have to get your hands on a 3.5mm mono jack and splice the cables together. There is only 12v, Ground and Signal connected to the X-Gyro so its obvious which is the signal cable to connect to the tip of the 3.5mm jack.  Then you have to use the Mixer settings to Replace the channel you assign for pan/tilt with PPM7 and PPM8. I'm not sure its worth using an X-Gyro 1000 though - mine drifts away from its centre position and I'm forever having to hit the centre button. No good.

  • Why use an analog dial or CLI for checking the PWM pulse widths when the feature is already available in Mission Planner. Just go to configuration and then flight modes and you can see the current PWM. change the value on your transmitter and you can read the pwm output in the mission planner.

  • Developer

    I still wonder a bit why to do hardware modification when you can do this all in software itself?

    Ok you need to spend 2 switches to do it and two radio channels. Using two radio channels might sound a lot but actually it is not as you can use in anyways only 7 channels on ArduCopter. Channel 8 is a big No No as it is been used for hardware failover mux. So never connect Ch8 to your APM when using ArduCopter software.


    I am using Ch5 and Ch6 to do all mixing and other to create all 6 different values from 3-way switch and with one 2-way switch which works as a multiplier for 3-way switch.


    When 2-way down, 3-way has

    N: Stabilize

    1: Alt hold

    2: Loiter


    2-Way up and 3-way has:

    N: Stabilize in simple mode

    1: Auto

    2: RTL


    Why this type of order. Well sure it can be something else too but as far for Pos-2, after loiter it's easy to switch to RTL just by flipping 2-way. Also Pos-N from stabilize to stabilize+simple is easy again by 2-way swtich


    Pos-1 Alt hold vs. Auto.. Same thing they are a bit similar features and when you start your missions it's nice to go first on althold and then to full auto. Also if something goes wrong you can easily abort Auto mode with one switch.


    This all works with original TGY software rather well. Just on first setup time you need to play a bit with mixing rates and end points to make different modes to be far enough.


    Radio channels are connected in way:

    RCV - APM

    1 - 1

    2 - 2

    3 - 3

    4 - 4

    5 - NC

    6 - 5

    7 - 6

    8 - 7


    In total of 7 channels are going in to APM which means that I can use all normal ail, ele, rud, thr channels and then mode channel, aux 1 (ch6) for camera pitch, aux 2 (ch 7) to other features like auto level trim and so on.



  • Admin


    Who wants to fine tune a fixed resistor?!! I assume you mean " a variable resistor/Pot ".  All I see in the topic is how to divide a variable Res/pot in fixed blocks of added value of resistors in series with help of 6 position switch. This method helps a vague position point of regular POT and as such with above said setup , one can be sure of the switch position and there by of Mode chosen. Could you be less cryptic on your description and point you would like to make. Tnx

  • Developer
    Here is original ARHEXA's post about the switch:
  • Developer
    @Ray Gunter
    I have NO connection to the "ebay Switch"...
    ARHEXA is the one who sells those "Switches" so i guess you should pm him for help !!!
  • Moderator

    Ray, what is the ebay link you bought from and what radio do you have. Try to be productive please.

  • try only to help . . .

    can you pm me the ebay link (so we don't promote someones prodcut) , will have a look maybe  we don't talk about the same switch

  • i have also bought the swicth few months before.

    i can tell you it works right out the box , but you have only to 

    recalibrate your TX 

  • Moderator

    @ RayGunter   What do you mean?
    The model on ebay is already wired with the resistors built in and has the correct wire colour indicated on it.
    How easier could it be?

    The instructions above are for a different type that does not have resistors built in.

    No one is lying.

This reply was deleted.