BasicMicro

Those commands are mainly for people coming from a sabertooth controller. To use them you must first use both a forward/backward command AND a turn left/right command. The values can be 0 for either but you must send both initially. The motor will start moving after the second command is sent. Then any new command will immediately affect the motors movement.

You can think of the two values as the equivalent of a RC controller with 2 sticks or a wheel and thottle.