Controlling 5 or more servos

Question

Hello!

This is my first post here, so sorry if it is not the best place for here.

I would like to build a smaller 5 DoF RRR robot controlled by Raspberry so I would like to control 5 (or maybe more) servo motors.

I read the RPi has only one Pin able to PWM, but can I use somehow more? If I can, how?

14rhb · Answer

You could run something like this off the I2C interface of the Pi 16-Channel 12-bit PWM/Servo Driver - I2C interface - PCA9685 - ADAFRUIT | CPC UK and have up to 16x servos !

luislabmo · Answer

sanyika95 , here are the options I can think of: Not so good : You can try Software PWM , but Linux -which I guess is what you are using on you RPi- is not a real-time operating system, so this may bring lag and a not so clean PWM signal as the servo controller software will be sharing CPU usage with the rest of the OS process. WiringPi may be helpful for you if you decide to take this route. A better option : get a RaspberryPi servo controller like this one from Adafruit , it will control those 5 servos easily, and there is documentation available for you to try. There is also an option from Pololu Robotics you can explore. Hope this helps. Luis.

genebren · Answer

Sandor,

There are several libraries (python/C) for turning GPIO pins into PWM pins. This should allow you to control multiple servos. Also, with the addition of some hardware it is possible to reuse a single PWM pin to generate multiple servo signals. I have designed some simple boards that used a single PWM, muxed out to multiple pins, generating up to six servo signals.

Best of luck on your robot design.

Gene