Arduino Forum

Using Arduino => Motors, Mechanics, Power and CNC => Topic started by: SouthernAtHeart on Feb 09, 2011, 05:47 pm

Title: stepper motor feedback
Post by: SouthernAtHeart on Feb 09, 2011, 05:47 pm
Is it possible to tell if a stepper motor has 'reached the end of the track' and is no longer turning whatever it was turning, thus giving you the ability to turn off power to it?
Title: Re: stepper motor feedback
Post by: jonnywhatsit on Feb 10, 2011, 08:35 am
You could either keep track of the motors position in software or use a sensor to give positional information (more reliable as the software could lose track).
Title: Re: stepper motor feedback
Post by: weirdo557 on Feb 10, 2011, 10:59 am
sounds like you need a limit switch.
Title: Re: stepper motor feedback
Post by: Grumpy_Mike on Feb 10, 2011, 02:28 pm
If you are cleaver you can measure the current in the windings and when it hits the end stop the current pulses will be bigger, however, it is a bit of a messy circuit depending on if you have a unipolar or bipolar motor.

I would go with a switch either mechanical, optical or magnet and reed relay or magnet and hall sensor.
Title: Re: stepper motor feedback
Post by: SouthernAtHeart on Feb 10, 2011, 03:48 pm
What about a servo. (continuous rotation)  It probably can't tell me if it's quit rotating, either.  I'm thinking of going the servo route.  If I give the command for my servo to make 2 revolutions and then detach the servo after a delay, and it only goes 1 1/2 revolutions, will this be a problem?  ...I mean, it won't hurt the servo