NKC Electronics Motor Controller question

Other Hardware Motors, Mechanics, Power and CNC
1

I purchased one of these http://www.nkcelectronics.com/freeduino-arduino-motor-control-shield-kit.html and have it running fine with bi-directional dc motors. My question is should I be able to put one bi-polar stepper motor in place of the 2 dc motors and run the example Steppers/stepper_oneRevolution?

It almost works but instead of turning, it just clicks. I have tried to change the speed and that failed as well. Tried swapping the phase of the steppers and that failed also.

2

I did some work with that shield a while ago and am pretty sure I tested it with bipolar steppers. Have you checked that your power supply can provide enough current?

3

Thanks for the quick reply..It is a very small motor under no load. I'm testing on the DVD rail mounted motor (see attached). The one attached to the worm gear drive and I've tried it on several voltages, 3,5,7,9,12 and it just thumps harder with more voltage. I have some more stepper motors coming next week to test with. I may have smoked this little critter in the testing :slight_smile:

BiPolar.jpg
BiPolar.jpg800×411 72.7 KB

4

I may have smoked this little critter in the testing

Might have. :wink:

You can run higher voltage then the motor is rated at as long as you have some kind of current limiting for the windings. Some motor controllers have automatic current limiting built in and if not you need to add series resistors for the motor windings to keep the current at or below the motor's max winding current specification.

5

Found some more info on this board. It should be able to run 1 stepper per this article by Dave Cuartielles:

http://blushingboy.net/p/motorShieldV3/page/Background/

It mentions shorting pin E1-E12 and E2-E22 to put it in stepper mode. The board from NKC has rev 1.4 on it and seems to have dropped the E12 and E22 pins, but the E1 and E2 holes are there and I found an unlabeled hole in the new board by Pin15 on IC3 ( sn75441). Looking at the schematic E12 and E22 are hanging off of pin 2 and pin 15 on IC3 respectively.

I will post more to this thread as I learn how to step a uni-polar motor with this board.

6

Got it working and driving a 3.1v stepper great now here is the code:

/* 
 Stepper Motor Control - one revolution created 30 Nov. 2009 by Tom Igoe
 D20110731- Working with DVD stepper motor at 23 steps/revolution. 
 Working with allTronics stepper as well, connected as follows
 
 http://www.allelectronics.com/make-a-store/item/SMT-355/3.1-VDC-STEPPER-MOTOR/1.html
 Red-Grey 40 ohms Red = Dir, Grey=Vel
 Yel-Blk  40 ohm Yel = Dir, Blk = Vel 
 Viewed with 5V/Gnd/Vin pins toward you, so motor jumper pins are at the lower left
 pin1-Red (top most pin)
 pin2-Gray
 pin3-Yellow
 pin4-Black 
 */

#include <Stepper.h>

// const int stepsPerRevolution = 23;  // For my tiny DVD stepper 
const int stepsPerRevolution = 48;  // For my AllTronics 3.1v stepper

// initialize the stepper library for the NKC motorshield          
Stepper myStepper(stepsPerRevolution, 10,12,9,13); 

void setup() {
  myStepper.setSpeed(60);  // set the speed at 60 rpm:
  Serial.begin(9600);      // initialize the serial port:
}

void loop() {
  // step one revolution  in one direction:
  Serial.println("clockwise");
  myStepper.step(stepsPerRevolution);
  delay(500);
  
  // step one revolution in the other direction:
  Serial.println("counterclockwise");
  myStepper.step(-stepsPerRevolution);
  delay(500); 
}