Atmega128 and LM629 Problem


I am using Atmega128 and LM629 for position control of DC motor.
The LM629 works fine when used in positive direction.
But when commanding to move in reverse direction i.e. say -5 revs, the trajectory is completed well before it completes 5 revs i.e. around 3-4 revs
The values for loading position control in -ve direction when calculated are found to be correct.

I request you to help me in solving this problem.
Any links or sample programs will also be helpful.


Hello Rohit,
The ATmega128 and LM629 are not Pololu products, so I have moved your post to the “Robotics Technical Discussion” group. Also, you will probably not get any useful help from anyone unless you provide some details about what you are doing, such as your code, information about your motor and power supply, a picture of your setup, oscilloscope traces, etc.


Hi Paul

Thanks for guiding

By the way the motor i am using is 24DC@60RPM local made.
My application involves abt spinning a platform in forward and Rev direction as specified by the user.
Let me see if I am able to post any picture or codes related to my project.
I have already mentioned when using in forward direction it works very well.