[ConKbot of Doom]

You have to mix the values in the code. In the default code, pins 13-16 have a mixed signal for one joystick drive.

Look for the one joystick drive section in user_routines.c

You'll see something like
pwm13 = pwm14 = LimitMix (2000 + p1_y - p1_x + 127);

that may not be exactly it, but it will be similar. I have heard that if you use a lot of interrupts in the code, pwms 13-16 get twitchy, so you may want to change them in the code to another pwm channel. We are keeping it simple on ours, 01 for right, 02 for left, 03 for the arm motor.

Good luck