the m1.writeMicroseconds(1000); is for when nothing is pressed, so the motor speed would go to zero (1000), and the myPulsetime = (mypulseTime + pulseIncrement); is for the variation of speed (the thing is that can't have a potentiometer because this project is going underwater, so I just wanted 1 button that would vary through 3 speeds) I put the m1.write because I didn't know what function or whatever I should use.