Bipolar-stepper driver (coded for Velleman VMA03 - Arduino motor and power shield)

VMA03 Bipolar-stepper driver

// Initializing pins
const int pwr_a = 3;
const int pwr_b = 9;
const int dir_a = 2;
const int dir_b = 8;

// Step delay, is used as delay between each half-step, in the motor driver. 
// This delay is measured in microseconds.
int stepDelay = 600;

void setup(){
  // Initialize the pins, in the correct type of mode.
	pinMode(pwr_a,OUTPUT);
	pinMode(pwr_b,OUTPUT);
	pinMode(dir_a,OUTPUT);
	pinMode(dir_b,OUTPUT);
}

void loop(){
	// Test loop, should make your stepper go 40 steps forewards and backwards, with 1 second delay.
	Step4FWD(10);
	delay(1000);
	Step4BWD(10);
	delay(1000);
}


// This method, is called in order to make the stepper motor make 4 steps forwards (depending on your wiring).
void Step4FWD(int NumberOfTimes){
  
  // The function will run for the amount of times called in the method.
  // This is accomplished by a while loop, where it will subtract 1 from the amount, after every run.
  
	while(NumberOfTimes!=0){
		// Starting position (if repeated, ful step (4))
		// EXPLINATION: in this case, both our power are high.
		// Therefore both coils are activated, with their standard polarities for their magnetic fields.
		digitalWrite(pwr_a,HIGH);
		digitalWrite(pwr_b,HIGH);
		digitalWrite(dir_a,HIGH);
		digitalWrite(dir_b,HIGH);
 
		delayMicroseconds(stepDelay);
 
		//Half step (½)
		// EXPLINATION: In this case, only out b-coil is active, still with it's stand polarity.
		digitalWrite(pwr_a,HIGH);
		digitalWrite(pwr_b,LOW);
		digitalWrite(dir_a,HIGH);
		digitalWrite(dir_b,LOW);
 
		delayMicroseconds(stepDelay);
 
		//Full step (1)
		// EXPLINATION: In this case, the b-coil is activated as in previous cases.
		// But the a-coil now has it's direction turned on. So now it's active, but with the reversered polarity.
		// By continuing this pattern (for reference: http://www.8051projects.net/stepper-motor-interfacing/full-step.gif) , you'll get the axis to turn.
		digitalWrite(pwr_a,HIGH);
		digitalWrite(pwr_b,HIGH);
		digitalWrite(dir_a,HIGH);
		digitalWrite(dir_b,LOW);
 
		delayMicroseconds(stepDelay);
 
		// Half step (1½)
		digitalWrite(pwr_a,LOW);
		digitalWrite(pwr_b,HIGH);
		digitalWrite(dir_a,LOW);
		digitalWrite(dir_b,LOW);
 
		delayMicroseconds(stepDelay);
 
		// Full step (2)
		digitalWrite(pwr_a,HIGH);
		digitalWrite(pwr_b,HIGH);
		digitalWrite(dir_a,LOW);
		digitalWrite(dir_b,LOW);
 
		delayMicroseconds(stepDelay);
 
		// Half step (2½)
		digitalWrite(pwr_a,HIGH);
		digitalWrite(pwr_b,LOW);
		digitalWrite(dir_a,LOW);
		digitalWrite(dir_b,LOW);
 
		delayMicroseconds(stepDelay);
 
		// Full step (3)
		digitalWrite(pwr_a,HIGH);
		digitalWrite(pwr_b,HIGH);
		digitalWrite(dir_a,LOW);
		digitalWrite(dir_b,HIGH);
 
		delayMicroseconds(stepDelay);
 
		// Half step (3½)
		digitalWrite(pwr_a,LOW);
		digitalWrite(pwr_b,HIGH);
		digitalWrite(dir_a,LOW);
		digitalWrite(dir_b,HIGH);
 
		NumberOfTimes--; 
	}
 
 TurnOfMotors();
 }


// This method, is called in order to make the stepper motor make 4 steps backwards (depending on your wiring).
void Step4BWD(int NumberOfTimes){

	while(NumberOfTimes!=0){
 
		// Starting position (if repeated, ful step (4))
		digitalWrite(pwr_a,HIGH);
		digitalWrite(pwr_b,HIGH);
		digitalWrite(dir_a,LOW);
		digitalWrite(dir_b,LOW);
 
		delayMicroseconds(stepDelay);
 
		// Half step (½)
		digitalWrite(pwr_a,LOW);
		digitalWrite(pwr_b,HIGH);
		digitalWrite(dir_a,LOW);
		digitalWrite(dir_b,LOW);
 
		delayMicroseconds(stepDelay);
 
		// Full step (1)
		digitalWrite(pwr_a,HIGH);
		digitalWrite(pwr_b,HIGH);
		digitalWrite(dir_a,HIGH);
		digitalWrite(dir_b,LOW);
 
		delayMicroseconds(stepDelay);
 
		// Half step (1½)
		digitalWrite(pwr_a,HIGH);
		digitalWrite(pwr_b,LOW);
		digitalWrite(dir_a,HIGH);
		digitalWrite(dir_b,LOW);
 
		delayMicroseconds(stepDelay);
 
		// Full step (2)
		digitalWrite(pwr_a,HIGH);
		digitalWrite(pwr_b,HIGH);
		digitalWrite(dir_a,HIGH);
		digitalWrite(dir_b,HIGH);
 
		delayMicroseconds(stepDelay);
 
		// Half step (2½)
		digitalWrite(pwr_a,LOW);
		digitalWrite(pwr_b,HIGH);
		digitalWrite(dir_a,LOW);
		digitalWrite(dir_b,HIGH);
 
		delayMicroseconds(stepDelay);
 
		// Full step (3)
		digitalWrite(pwr_a,HIGH);
		digitalWrite(pwr_b,HIGH);
		digitalWrite(dir_a,LOW);
		digitalWrite(dir_b,HIGH);
 
		delayMicroseconds(stepDelay);

		// Half step (3½)
		digitalWrite(pwr_a,HIGH);
		digitalWrite(pwr_b,LOW);
		digitalWrite(dir_a,LOW);
		digitalWrite(dir_b,LOW); 
 
		NumberOfTimes--;
	}
 
 TurnOfMotors();
}

// This method simply just turn of the motors, called when ever we don't need the motors anymore.
// In this way, we won't fray the circuit or coils.
void TurnOfMotors(){
	digitalWrite(pwr_a,LOW);
	digitalWrite(pwr_b,LOW);
	digitalWrite(dir_a,LOW);
	digitalWrite(dir_b,LOW);
}

great work ... thanks a lot ... I made a arduino library based on your code.

Pls. try or/and review at https://github.com/hoefeler/VMA03