i've got a shift register connnected to an h-bridge connected to a 4-pin stepper motor. further down the shift register there are some LEDs. When I try to power the stepper motor, the LEDs further down flicker about in nonsensical ways. the shift register, or maybe the whole board seems to freak out. i have an ir sensor connected that is being triggered when it shouldn't be during the freak out. does anyone know why that would happen?
just having the shift register + h-bridge disconnected from the stepper motor doesn't cause this. i'm following the typical Physical Computing method for controlling bipolar stepper motors. i haven't been able to figure out what the order of the 4 pins is.
any tips on dealing with this? is it about isolating that noise, or am i just doing something very wrong?
The LEDs don't flicker if I run the software with the motor disconnected.
The "Physical Computing method" I was referring to is that stepper motor/h-bridge diagram from the book Physical Computing. This one, from the authors website, is the same, and the one I linked to above: http://www.tigoe.net/pcomp/img/stepper-bipolar-hbridge.jpg
on a whim i added 10K resistors on pins 2 and 4 (or maybe 1 and 3) of the stepper motor, and everything worked as it should, except the resistors started smelling and turning black after a minute or so. so... stronger resistors?