Blown MUX?

Hello people, i need to share this with all of you to see if we end with some sort of diagnose procedure to know if we have a blown MUX, and the posible ways to solve the problem.


  • ardupilot
  • arduimu
  • shield with air speed sensor
  • ublox gps
  • no reset button
  • lipo sensing pin activated
  • telemetry with xbee pro
  • CGS
  • electronic speed control (for motor)

  • Have soldered the ardupilot with all the jumpers in order to use throttle and channel 4 as a rudder.
  • conected the gps to the imu
  • conected the imu to the shield on the +5, gnd, rx pins
  • conected the xpee to the shield on the +5, gnd, tx pins
  • in 1 to receiver ailerons
  • in 2 to receiver elevators
  • in 3 to receiver throttle
  • in 4 to receiver rudder
  • crtl to receiver gear
  • out 1 to aileron servo
  • out 2 to elevator servo
  • out 3 to speed control
  • out 4 to nose wheel (no rudder for now, Vtail not suported)
  • mux in 3 to pin d8
  • mux in 4 to pin analog 4
  • vcc pin to positive out 1
  • d11 pin to thottle in signal
  • d13 pin to 4 in signal.

  • gps lock and data working ok
  • arduimu working ok
  • telemetry working ok
  • throttle sensing (input on 3 in) working ok
  • Rudder sensing (input on 4 in)  working ok
  • Elevator sensing (input on 2 in ) working ok
  • Aileron sensing (input on 1 in ) working ok
  • Crtl sensing input working ok
  • aileron output (out 1) working good in all modes
  • elevator output (out 2) working good in all modes
  • throttle output not working at all
  • rudder output not working at all

  • changed the mux in 3 -- throttle to mux in 4 -- throttle with no success!
  • changed the mux in 4 -- analog 4 to out pin 4 --- analog 4 and rudder works.
Final result:

  • BLOWN MUX??????????????
please tell me what else to try i have been reading also all the code to see if i can find some sort of solutions.........

thanks people...

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

Join diydrones

Email me when people reply –


  • WOW...... this is amazing.... everything works good now.......... also wired the rudder...... good as espected ..... now gonna fly and tune...

  • found my problem..... i feel so bad in this moment (bothering you because of my fault)....... jordi sugested me to download the eagle file of the board as a tool to check my AP...
    it happends that in the manual i saw the instruction to cut the trace but did not understood why!!! and also by mistake i broke the mux 3 trace...........

    o boy i feel soooooooo bad..... soooooo dumb....... it was not a solder problem, was a cuting problem...

    smashed my head to the table for half and hour when i saw it......
    tested it, now is working....

    so........ !!!!! IT IS NOT A BLOWN MUX !!!!!

    Note: still feeling dumb........... fu@*&k......

    Chris...... !!!thanks so much for your patience!!!!.....
  • I have a turnigy 60amp. Esc.
  • 3D Robotics
    The MUX only controls channels 1 and 2, so you're fine there. The problem is probably a soldering error with the jumper wire for throttle on the bottom of the board. Please check it again. Also test if if works with the shield not attached.
This reply was deleted.


Shivchand Jaysaval liked Shivchand Jaysaval's profile
Aug 25