At every start of our system, we notice that the ServoMotor isn't at the same position with the same command signal. So we can't find the command signal to go straight. Is it normal or not? Our ServoMotor is it break?
Thanks for your answer.
something you might want to check: Sometimes the servo (or anything mechanically moved by it) might hit a mechanical limitation. This can deposition the lever (yellow plastic part) on the servo's axle. The servo's axle has a big momentum. In software you could limit the min/max positions to avoid running into mechanical limitations. But during powering up or flashing the system, these software limits don't apply yet and the servor can drive the mechanics still into physical limits with quite some momentum. Same for the motors, by the way. It's a good idea to power the motor control board only when proper software limitation is running. De-powering it while flashing or resetting of the controller board might help.
Of course your problem can also have another cause like e.g. a broken servo.