Controlling a DC Motor

musictech

I am modifying a Robosapien v1 for a school project. I am replacing the PIC controller with a Stamp(s). I have several boards of education along with a few Pololu Micro Dual Serial Motor Controllers.

The robosapien uses 3v dc motors. With the Pololu Controller, I can easily control the motors. My problem is the motors that are controlling mechanical joints. I can't figure out how to determine when the motor has reached the mechanical range of the joint. So that I can stop it. Any help would be helpful.

Thanks

Robert Schwartz

There are a number of ways to do this. You can use sensors (like IR) on the limb itself to setermine the distance between it and the body. You can replace the joint motors with steppers and figure out the angle needed to travel, you can use a wheel encoder to determine the speed travelling and the total distance the joint should travel, or you can just time the joint to see how long it should go. Good luck!

Paul Baker

check out this thread http://forums.parallax.com/showthread.php?p=525320 in it is a link to a circuit which monitors how much current a motor·is drawing.·A stalled motor (ie not moving) draws more current. The circuit as configured will automatically shut off the motor when the current goes above a threshold.

Chris Savage

Do you know how the device currently detects the limb movement limits?· That might also be a good place to start.· Although I'd be inclined to think it does what Paul suggests.



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