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[on:]

Hi, I and very interested in Arduino and now trying to understand a small stepper motor.

The exact motor and driver board can be found here http://www.4tronix.co.uk/arduino/Stepper-Motors.php.   Though I did not purchase it from there.

The arduino sketch on that page works perfectly. It will compile and run just as it says.  All four leds work and the motor does an entire revolution then reverses just as it says it will.

All I am trying to do now is get the Arduino sketches found in the library working with this motor and driver board. The library and examples I'm speaking of are found in the Arduino 1.0.2 version library under Stepper.  The one example in particular I am trying to work, since it appears to be the easiest, is entitled "stepper_oneRevolution.ino"

When I compile and load this, all that happens is the lights blink and the motor buzzes approx one second on then one second off.

Any and all help would be appreciated.

Thank you in advance,

Rick Eis
Arizona USA

[Reply #1 on:]

Your motor is geared down.
// The 28BYJ-48 motor is a 4-phase, 8-beat motor, geared down by
// a factor of 68. One bipolar winding is on motor pins 1 & 3 and
// the other on motor pins 2 & 4. The step angle is 5.625/64 and the
// operating Frequency is 100pps.

[Reply #2 on:]

LarryD, if you can be more helpful, I'll appreciate it. Yes, it is geared down but what that means? How it relates to what the original posted observed (1 second on, 1 off)? I just received the similar board and controller today and am eager to try it on.

Thanks in advance.

[Reply #3 on:]

I have the same motor as you.

The arduino sketch on that page works perfectly. It will compile and run just as it says. All four leds work and the motor does an entire revolution then reverses just as it says it will.

The above program is written for half stepping a unipolar motor driving a gear box.
This is a very good sketch for your application and could be changed for high torque 2 phase stepping if you need more power.
The Stepper library is designed for Direct Drive (not geared) high torque 2 phase stepping motor applications.  It is for motors without a gear train.  You would have to rewrite it to work with your geared motor.

[Reply #4 on:]

Yes, it is geared down but what that means?

I believe what he's hinting at is that you're trying to run the motor too fast.  Because of the way it's geared, it doesn't behave exactly like the example code.  If the output shaft were coming directly from the motor part, you would only have something like 64 steps to complete a full circle.  Since your motor has more gears inside, it will take more full spins of the motor part to get the final shaft to spin a full circle, but it has the same "top speed" (number of steps per second).  If you try to get your unit to run a full circle at the normal speed, it has to spin at about 68 times faster than the example is designed to do.  I hope this is clear and correct.

[Reply #5 on:]

I modified "stepper_oneRevolution.ino" to get closed to what you wanted.
Please play with the variables to get closer to exactly 1 revolution.
Note: I had to swap 8 & 11 on my motor to get this to work.
Also this code will lock up the loop until the motor is finished moving, not what you really want...

Code:

/*
 Stepper Motor Control - one revolution <<<<<<<<<<<<<<<<<<<<< Modified
 
 This program drives a unipolar or bipolar stepper motor.
 The motor is attached to digital pins 8 - 11 of the Arduino.
 
 The motor should revolve one revolution in one direction, then
 one revolution in the other direction.  
 
  
 Created 11 Mar. 2007
 Modified 30 Nov. 2009
 by Tom Igoe
 
 */

#include <Stepper.h>
const int stepsPerRevolution = 200;  // change this to fit the number of steps per revolution
//const int stepsPerRevolution = 200;  // change this to fit the number of steps per revolution
                                     // for your motor

// initialize the stepper library on pins 8 through 11:
//  Stepper myStepper(stepsPerRevolution, 8,9,10,11);              
  Stepper myStepper(stepsPerRevolution, 11,9,10,8);   // <<<<<<<<<<< Note 8 & 11 swapped
void setup() {
  // set the speed at 60 rpm:
  myStepper.setSpeed(120);                  //<<<<<<<<<<<<<<< This was 60
  // initialize the serial port:
  Serial.begin(9600);
}

void loop() {
  // step one revolution  in one direction:
  Serial.println("clockwise");
//**************************    
  for (int x=1;x<12;x++)                         //<<<<<<<<<<<<  we want to iterate to get a full revolution
  {
  myStepper.step(stepsPerRevolution);
  Serial.println(x);                                 //<<<<<<<<<<<< This is just for debugging
  }
//**************************    
  delay(500);
  // step one revolution in the other direction:
  Serial.println("counterclockwise");
//**************************    
  for (int x =1;x<12;x++)
  {
  myStepper.step(-stepsPerRevolution);
  Serial.println(x);  
  }
//**************************  
  delay(500);
}