Pic Transmitter channel problem

Transmitter for a PIC controller, channel 2 changed to channel 3 and visa-versa. In all six config’s, with motor wires in ports 1 and 2, the motor in port two is controlled by joystick channel 3.
Can I reset the entire transmitter?

These things can also be controlled by programming on the PIC, so most likely that CPU is the part that needs to be reprogrammed, rather than the joystick.

DaveP also writes in the official support forum:

The usual reason for this situation is that the trim on the joystick is set to non-zero (or the sticks are not set to center). You can use the trim function of the joystick to adjust this until the motors stop moving or humming, when the joysticks are in the centered position. Does that work, or at least affect the situation?

Fixed that for you.
What else did you try?

I’ve zeroed the trims and cleared out the pic by downloading both the master code and user code. When turning on, one basebot, motor two stays running full speed and the other basebot, both motors run full speed.

  1. Are all other ports (digital analog inputs, interrupts) in the PIC unplugged?

  2. Are using 74.xxMHz crystals, or hardwired tethers between TX and PIC?

  3. Since you have two of each tx/rx, when you swap tx and pic, does the problem follow the TX or the PIC?

  4. Have you swapped motors to show that the problem follows the PIC port, not the motor?

  5. When you turn on the PIC, and some motors run spontaneously at full speed (your problem report), does moving the joysticks or back buttons change the motor speeds at all?

  6. What version of Master code did you load?

  7. What version of Vex provided User code did you load?
    If user provided usercode, zip it and attach the code you loaded.

  8. Do you have a programming kit? Which one (RobotC, EasyC)

  9. Have you tried controlling the motor ports directly from code to show it is a motor port problem?

  10. Have you tried reading the joystick values from code and printing to screen to show that the joysticks are sending the wrong values?

Both problems resolved. The robot with the one wheel spinning at full speed was a trim problem. The situation where two wheels spinning at full speed is narrowed down to the transmitter. And…the problem went away and then returned within 5 minutes. Inconsistent. When the problem stopped, I did not do anything other than turn transmitter and controller on.
Thanks for your help.