/*
	Stepper Motor Controller
	by Kevin Filteau 2010-05-29
	Playwithmyled.com
*/

// Motor controller pins.
#define pinMotorCtrlA 4
#define pinMotorCtrlB 7
#define pinMotorEnA 5
#define pinMotorEnB 6

// Direction constants.
#define GOLEFT 0
#define GORIGHT 1

// Motor states and position.
boolean motorRunning = false;
int motorMax = 700;
int motorPos = 0;

/**********************************************
	MOTOR
**********************************************/

// Setup the motor.
void motorSetup() {
  pinMode(pinMotorCtrlA, OUTPUT);
  pinMode(pinMotorCtrlB, OUTPUT);
  pinMode(pinMotorEnA, OUTPUT);
  pinMode(pinMotorEnB, OUTPUT);
  // Everybody to LOW.
  digitalWrite(pinMotorCtrlA, LOW);
  digitalWrite(pinMotorCtrlB, LOW);
  digitalWrite(pinMotorEnA, LOW);
  digitalWrite(pinMotorEnB, LOW);
}

// Free the motor.
void motorFree() {
  digitalWrite(pinMotorEnA, LOW);
  digitalWrite(pinMotorEnB, LOW);
}

// Make the motor spin one step in the direction specified.
void motorSpin(boolean dir) {

	static int pos = 0; // Starting step pos.

	int stepsSeq[] = {0xC0,0x30,0x40,0x20}; // Registry value.
	int st;

  // Timing
  static unsigned long previousMillis;
  long interval = 3;

	if(millis() - previousMillis > interval) {
		previousMillis = millis();

		st = stepsSeq[pos];
		if( dir == GOLEFT ) {
			pos++; if(pos>3) pos=0;
			motorPos++;
		} else {
			pos--; if(pos<0) pos=3;
			motorPos--;
		}
		PORTD &= 0xF;
		PORTD |= st;
	}

}

/**********************************************
	MAIN FUNCTIONS.
**********************************************/
void setup() {
	motorSetup();
	motorReset();
}

void loop() {
	motorSpin(GOLEFT);
	// motorSpin(GORIGHT);
}