Quote Originally Posted by sougata View Post
Hi All,

I really do not fit in this thread cause I have no experience in robotics but perhaps can share some view.

Creating a complementary output just by inverting the PWM out pin and feeding one part.

1. If you are driving a H-bridge then applying a 50% duty doesn't move motor.

2. Anything less than 50% or greater than 50% would result in motion in either directions. Speed prportional to duty cycle.

3. Shutting down both half causes braking.

Darrel has done a Multiple Soft PWM stuff. Find it here http://www.pbpgroup.com/modules/wfse...p?articleid=12 . It can be easily adopted to get complimentary outputs. Also possible to include dead times.

Only the PWM freq cannot be high (if you have other tasks to do in between, you run out of cycles). However for a two channel version it should work with some audible noise from the motor. Don't blame me if you burn one.
Exactly...software pwm, run as many channels as you have cpu time to handle, at any rate.

Complementary PWM - exactly! Easy to do with software PWM, one bit mirrors the other...

Very easily done. Not hard to grasp...