Comments on: Stepper Motor Controller Board

By: Micromouse

Micromouse — Wed, 24 Mar 2010 19:03:17 +0000

I am planning to use “Allegro A3977″ in my robot. Do you know any website that has a good schematic of a complete stepper motor driver circuit? The one that you used, may I get the schematic for that? I will really appreciate it.

By: Adrian

Adrian — Mon, 27 Apr 2009 07:34:59 +0000

Hello rv,

Please tell us more info about this circuit what you need becase maybe you want variable speed or not, maybe you need a period to left and then right automatic….
1. Use a 555 circuit for step, you can find on internet 1000 of schematic and the a swich for direction….
2. You can use a pic microcontroler pig 12f509…. 16f84a.
(with pic 12f509 you need only one reset button and an resistor).
Sorry for my English.

By: rv

rv — Thu, 23 Apr 2009 21:26:26 +0000

hello everyone,,,
i need a simple circuit for running a stepper motor clockwise and anticlockwise WITHOUT USING ANY OF THE PC PORTS…plzzzz help….

By: Keith Neufeld

Keith Neufeld — Sat, 15 Nov 2008 17:58:22 +0000

M. Timm, since the stepper’s coils are inductive loads, you’re going to get a huge current through your driver if you do that. That’s about as far as I can guess.

By: M. Timm

M. Timm — Fri, 14 Nov 2008 04:25:21 +0000

Boris! What happens if I reverse the polarity for a micro second of the pole I am leaving to get to the next pole of a stepper (bipolar stepper)?
What am I going to fry now?
If you respond, thanks

By: Adrian

Adrian — Tue, 16 Sep 2008 15:20:21 +0000

Hello Boris and also all,

I got the same problem with DIR on my test board. I tried to find an answer but nothing until now. I will try again this week and I hope I will not have the same problem with the new A3977 IC.

By: Keith Neufeld

Keith Neufeld — Wed, 23 Jul 2008 00:08:00 +0000

Boris, this may sound silly, but double-check that you have a good logic ground connection between the A3977 board and whatever is feeding signals into it. That really sounds like a floating ground problem.

If that’s not it, tell me more about how fast you’re trying to step the motor and exactly what happens when you try to go the other direction. Does it move at all, jitter back and forth, growl? Can you turn the motor shaft freely by hand, or is it held stationary?

By: boris

boris — Tue, 22 Jul 2008 23:40:25 +0000

Hello, I am working in a board prototype for motor control and I need
some help. In my development, I am using a3977klpt controller and i am
having some problems. when I test the board connected to a motor , this
motor only works in a one direction. if the DIR pin is logic low and
step pin set by pc, this circuit works fine, but if the DIR pin is logic
high (5VDC, the same as VDD controller), the motor not works in other
direction, it is bloked.

Can you help me?

By: Keith Neufeld

Keith Neufeld — Fri, 31 Aug 2007 17:59:43 +0000

Nora, here are several working A3977 boards available online that I found via Google:

http://www.thsengineering.com/projects/a3977proto/a3977proto.html

http://www.students.tut.fi/~kontkant/a3977.php.html

http://pminmo.com/ss3977/ss3977.htm

My board design is still in the prototyping phase and not finished yet, so I don’t think it would be useful to you.

By: nora

nora — Fri, 31 Aug 2007 02:38:51 +0000

Hello,Keith,would you please mail the tipical applicition of A3977 circuit diagram to me? i need your help.Thanks a lot.

my e-mail,****************@sina.com.