// This Arduino example demonstrates bidirectional operation of a

// 28BYJ-48, using a ULN2003 interface board to drive the stepper.

// 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. Current draw is 92mA.

////////////////////////////////////////////////

//declare variables for the motor pins

int motorPin1 = 8; // Blue - 28BYJ48 pin 1

int motorPin2 = 9; // Pink - 28BYJ48 pin 2

int motorPin3 = 10; // Yellow - 28BYJ48 pin 3

int motorPin4 = 11; // Orange - 28BYJ48 pin 4

// Red - 28BYJ48 pin 5 (VCC)

int motorSpeed = 1200; //variable to set stepper speed

int count = 0; // count of steps made

int countsperrev = 512; // number of steps per full revolution

int lookup[8] = {B01000, B01100, B00100, B00110, B00010, B00011, B00001, B01001};

//////////////////////////////////////////////////////////////////////////////

void setup() {

//declare the motor pins as outputs

pinMode(motorPin1, OUTPUT);

pinMode(motorPin2, OUTPUT);

pinMode(motorPin3, OUTPUT);

pinMode(motorPin4, OUTPUT);

Serial.begin(9600);

}

//////////////////////////////////////////////////////////////////////////////

void loop(){

if(count < countsperrev )

clockwise();

else if (count == countsperrev * 2)

count = 0;

else

anticlockwise();

count++;

}

//////////////////////////////////////////////////////////////////////////////

//set pins to ULN2003 high in sequence from 1 to 4

//delay "motorSpeed" between each pin setting (to determine speed)

void anticlockwise()

{

for(int i = 0; i < 8; i++)

{

setOutput(i);

delayMicroseconds(motorSpeed);

}

}

void clockwise()

{

for(int i = 7; i >= 0; i--)

{

setOutput(i);

delayMicroseconds(motorSpeed);

}

}

void setOutput(int out)

{

digitalWrite(motorPin1, bitRead(lookup[out], 0));

digitalWrite(motorPin2, bitRead(lookup[out], 1));

digitalWrite(motorPin3, bitRead(lookup[out], 2));

digitalWrite(motorPin4, bitRead(lookup[out], 3));

}