Re: Single Joystick Control-Four motors
Assuming that you are talking about turning rather than sideways motion and you are using one joystick and two motor ports, you just need to use a little algebra like so:
You can get more complicated than that if you want. It is useful to special-case hard right and hard left turns (joystick horizontal movement only, no vertical component) to force the robot to spin rapidly right or left. I'll leave that as an exercise for the reader.