Servo does not stop

Hallo, I have problems with my servocontroller (Pololu Micro Serial Servo Controller). If I want to control it with the pololu transmitter the servos do not make a move. And if they move and I let them turn to position 0x7F and I want to let them turn to position 0x00 they do not turn into the other direction. Instead they want to turn further (and maybe destroy themselves) and they do not listen to any commands coming after that. I wrote a Java program to control the servos with the keyboard but the same problem occurs. After switching the power on the servos already want to move further than the end and they do not accept any commands.
Is there anything what I have to do for initialising or something similar?
Thanks for your help.

It sounds like you might be having two separate problems, one being that your code isn’t sending the correct bytes to control the servos, and one being intermittent startup pulses making your servos twitch.

What bytes are you sending from your program, or could you post your code? If you unplug all of your servos and send commands from your program, what do the servo controller LEDs do? If you don’t send any commands to your servo controller, do your servos still move erratically?

You might want to take a look at this thread. Specifically, are your servos behaving like the servos in this video? If that looks like your problem, try adding 4.7Kohm pull-down resistors between the servo signal line and ground, then take a fresh look at your code.


Hi Adam, thanks for your reply!

The problem is solved. The current limitation of my power supply unit was too low. If the servo gets enough current everything works all right.