0

I have been given this arm:

Imgur

It consists of 4 servos, which need to be controlled individually.

Can I control them using Gertboard? Gertboard has only one motor driver, but it also has several open collector ports and buffered outputs.

I know Raspberry Pi itself can control a servo through a PWM pin and that you can emulate PWM on any additional pins. How do I do it safely via Gertboard? Should I use buffered pins? Won't servos blow my Pi or Gertboard up?

1

You can connect a servo control wire direct to a Pi gpio and use hardware timed PWM to control the servo position. You could have an in-line resistor if you prefer (say 1K-10K).

I don't know if you can generate reliable PWM on a Gertboard. Software timed PWM is unlikely to give satisfactory control of servos. That said, there is little harm in trying, at worse you will shorten the servo's life a little.

  • So a servo can't damage the computer like DC motors can? Will the resistor prevent any damage? – katspaugh Dec 5 '14 at 13:15
  • 1
    A resistor may help prevent damage if you wire it incorrectly, i.e. connect to 5V when you meant to connect to the control wire. I don't use them myself. Frankly they might cause more problems then they solve as far as the servo control wire is concerned. Servos have in-built motor driver boards. Motors don't. You should always control motors via a motor driver board or motor driver chip. Again, I don't use resistors between the gpios and the motor driver board. – joan Dec 5 '14 at 13:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.