AVR-Chat

>     Iam stuck at coding the stepper motor drive. I need some help on
> implementing a bipolar stepper motor and writing its code to program
> the microcontroller. The stepper motor has to generate a sweeping
> pattern to find the location of the object...Iam in need of help from
> some experienced avr programmers. Also suggest me some links for
> bipolar stepper motor codes...
> Thanks a lot in advance...
> Cherry.


Look for "control of stepping motors" by douglas jones, you can easily  
find it with google.
It has all you will need.

The IR detectors are no heavy load, so you can use the simplest and  
smallest circuit (because you don't need any design that allows high power  
or faster speed). You will have H-bridges to drive the motor, but the  
document by Douglas Jones will tell you all you need to know about it.

Of course you will need some more or less clever software to do the  
sweeping and looking, but i think that is your task. A simple solution  
could be to just continously rotate the sensor, and determine where the  
signal was strongest. Better methods might be once the position is know  
the sensor tracks the source, only sweeping a smaller angle. Another hint  
would be that you might want a absolute position sensor for your motor  
(zero position). i mention it because it is important for hardware design  
and should be known early. A light barrier switch works well for that.

I don't think you need to find any existing stepper motor control codes,  
you will be faster making your own, it is just output of a fixed pattern,  
no more.


ST