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Author Topic: no response from stepper  (Read 581 times)
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hello,
i just got a big easy driver stepper motor driver from SparkFun. I wanted my stepper to run a little smoother than it did with an h-bridge and plus i fried the h-bridge chip anyway running some weird code. i'm very new to steppers and having the hardest time with them for some reason.

so i hooked up the big easy driver just like in this tutorial: http://bildr.org/2012/11/big-easy-driver-arduino/#mototPairs

ran the code from the page (one_stepper_example.ino)

uploaded it to arduino, gave the easy driver 12V. the light on the driver turned on, the arduino took the code, but there is 0 reaction from both steppers i tried. i multimetered everything out and it's going where it should, i think. there is one thing, though, that when i multimeter from the stepper wire onto the easyDriver board, it is a little strange. A1 beeps for A1, but when I test A2 to A2 nothing beeps. A2 does beep, though, on A1. Same exact thing with the B wires. I assume this is because there is resistance in the motor and stuff like that i don't understand. does everything sound hooked up correctly? and if it is hooked up correctly, any idea why i'm getting no response from the motor? i'm using a 12V 5A wall wort. I messed around with the potentiometer on the driver also to no avail.

here's what the board looks like in case anyone could notice any glaring mistakes...
https://dl.dropboxusercontent.com/u/7072449/2013-06-06%2017.27.21.jpg

thanks so much for any feedback
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Not sure what is going wrong but you must never apply voltage to a device then power up the arduino it needs to be the other way round or you might damage it.
Never make resistance measurements when a device iis powered up or connected up to a processor. Again damage will happen.
Try and check out your arduino's outputs are still working, try switching the drivers pins by hand.
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Thanks for the advice. I didn't do any of that stuff. I always have the arduino on first, upload the code and then apply the 12V. Everything was off when I was checking the resistance. The arduino out pins are working.

Has anyone else had this problem? I googled around and found a few other people with this problem but no responses. I know it's a long shot. Just wondering if there was anything obviously wrong from the picture or any little thing I'm missing.
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Determine the windings with the motor disconnected from the driver board.

Once you've paired up the two windings, call them A and B and connect to the right pairs of
pads on the driver board.   I'm assuming a 4-wire stepper motor - is that the case?
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Have you tried swapping the connections to A1 and A2 over?
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Have you tried swapping the connections to A1 and A2 over?

That can only change the direction of steps.  Swapping A1<->A2 or B1<->B2 or swapping both As for both Bs will each
change the direction of rotation.  Miswired states have a winding connected to one A terminal and one B terminal,
which is wrong.  A's drive one winding, B's drive another.  Direction can be sorted out in software or by swapping
one winding's wires.
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Have you tried swapping the connections to A1 and A2 over?

That can only change the direction of steps.  Swapping A1<->A2 or B1<->B2 or swapping both As for both Bs will each
change the direction of rotation.  Miswired states have a winding connected to one A terminal and one B terminal,
which is wrong.  A's drive one winding, B's drive another.  Direction can be sorted out in software or by swapping
one winding's wires.

If winding A is trying to turn in one direction and winding B in the other, then the motor won't turn. It may 'chatter', depending on the frequency of the PWM, but it won't turn. Reversing the connections to BOTH windings will reverse the direction the motor turns, only if both windings are trying to turn the motor in the SAME direction.
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Have you tried swapping the connections to A1 and A2 over?

That can only change the direction of steps.  Swapping A1<->A2 or B1<->B2 or swapping both As for both Bs will each
change the direction of rotation.  Miswired states have a winding connected to one A terminal and one B terminal,
which is wrong.  A's drive one winding, B's drive another.  Direction can be sorted out in software or by swapping
one winding's wires.

If winding A is trying to turn in one direction and winding B in the other, then the motor won't turn. It may 'chatter', depending on the frequency of the PWM, but it won't turn. Reversing the connections to BOTH windings will reverse the direction the motor turns, only if both windings are trying to turn the motor in the SAME direction.

Bipolar stepper motors are driven in quadrature, I don't think you understand this.  Each winding by itself has
no say in the direction, its the relative phase of the A and B windings that determines the direction.  Reverse
the sense of the current in A (leaving B unchanged) and the direction will reverse, ditto for B, ditto for swapping the roles
of A and B.  Each acts just like a reflection of the motor geometry in space, and a reflection in  space reverses
the direction of rotation.

I've a stepper motor right here in front of me, trust me this is how they work.
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