One Joystick Drive

[Mark McLeod]

The IFI default code does the axis mixing for you with this section of code in user_routines.c depending on how your motors are hooked up (both forward or one forward, the other reverse).

/*---------- 1 Joystick Drive ----------------------------------------------
*--------------------------------------------------------------------------
* This code mixes the Y and X axis on Port 1 to allow one joystick drive. 
* Joystick forward = Robot forward
* Joystick backward = Robot backward
* Joystick right	= Robot rotates right
* Joystick left	 = Robot rotates left
* Connect the right drive motors to PWM13 and/or PWM14 on the RC.
* Connect the left drive motors to PWM15 and/or PWM16 on the RC.
*/ 
pwm13 = pwm14 = Limit_Mix(2000 + p1_y + p1_x - 127);
pwm15 = pwm16 = Limit_Mix(2000 + p1_y - p1_x + 127);

However, I might not quite comprehend what you are asking, since if you make the left motor go slower than the right motor, the robot will only turn to the right by rotating counter-clockwise (what I'd normally consider turning to the left). If this is the case you could invert the x axis of the joystick prior to mixing, e.g., p1_x=254-p1_x;