You might be able to use Pi-Blaster, which uses some software trickery to get PWM on normal GPIO pins without using much CPU.Whillikers wrote:Sorry for posting what's probably an extremely simple question, but, though I have some robotics experience, this is my first time using the Pi.
I've got a project that requires controlling two DC motors and one servo. I plan to use http://store.ryanteck.uk/collections/fr ... =741358763 for my motor controller, but I've read that only GPIO pin 18 can send the PWM signals required to control servos, and the controller takes up pins 1-26. However, it looks like the controller has its own GPIO pins that might act like extensions of the pins it takes up, allowing me to control a servo from the extended pin 18, or even attach another board that's a dedicated servo controller. Is this the case?
My backup plan is http://www.mikronauts.com/raspberry-pi/robopi/, which looks like it has both motor and servo controllers. However, at $50 for the board + ICs, it's quite a bit more expensive.
As far as I can tell, the Ryantek board uses GPIO pins 17, 18, 22, and 23, but passes the rest through to the header.Whillikers wrote:Pi-blaster seems great. Thanks!
Does that mean that the pins on the motor controller do not extend the GPIO, though? At this point it's pretty irrelevant to the project since Pi-blaster should fix my issues, but it'd be good to know for future stuff.
In addition to RPIO.GPIO hardware timed PWM is also available from piblaster, pigpio, and servoblaster.Hove wrote:RPi.GPIO is software PWM so may not be fit for purpose depending on the resolution / accuracy you need.
Hardware PWM is available from RPIO http://pythonhosted.org/RPIO/ but you have to install it manually - it's not included in the standard distribution