// Example sketch to control a stepper motor with A4988 stepper motor driver 
// and Arduino without a library. 
// More info: https://www.makerguides.com

// Define a default wait time
int WaitTime = 2000; //Set a default wait time of 2000ms / 2 seconds between presenting and retracting targets

//Define the pin to enable the motors
int EnPin = 8;

//Set Direction Pins for Motors 1-4 (Using an array so they are counted as 0-3 rather than 1-4)
int DirPins[] {5,6,7,13};

//Set Step Pints for Motors 1-4 (Using an array so they are counted as 0-3 rather than 1-4)
int StepPins[] {2,3,4,12};

#define StepsPerRevolution 200 //Assumes that all motors are the same and have 200 steps per revolution / 1.8 degree steps

void setup() {
// Set the inbuilt LED
pinMode(LED_BUILTIN, OUTPUT);

  // Declare motor pins as output:
for (int i = 0; i <= 3 ; i++) {
  pinMode (DirPins[i], OUTPUT);
  pinMode (StepPins[i], OUTPUT);
         }
//Enable the motors
  digitalWrite(EnPin, LOW);

// The built in LED will flash twice quickly during initial setup
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(500);                       // wait for half a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(500);                       // wait for half a second
 digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(500);                       // wait for half a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(500);                       // wait for half a second

}

void loop() { //The code will repeat indefinitely

// The built in LED will flash each time the sequence restarts
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);                       // wait for a second


// Present 10 targets by randomly choosing one of the four possible targets each time

 for (int i = 1; i <=10; i++) {
        int TargetNumber = random(4);
        PresentTarget(TargetNumber) ;
        delay (WaitTime);
        RetractTarget (TargetNumber) ;
        delay (WaitTime);
        }
}

void PresentTarget (int TargetNumber){

//Present the selected target by spinning the relevant motor clockwise

        // Set the spinning direction for the selected motor to clockwise:
        digitalWrite(DirPins[TargetNumber], HIGH); //Look up the direction pin for the current motor in the direction pins array (DirPins) and set it HIGH for clockwise motion

        // Spin the stepper motor 90 degrees:
        for (int i = 0; i < StepsPerRevolution/4; i++) {
          // These four lines result in 1 step as the stepper motor steps on the rising edge of a digital wave - Transition from Low to High:
          digitalWrite(StepPins[TargetNumber], HIGH); //Look up the step pin for the current motor in the step pins array (StepPins) and set it HIGH to create a rising edge on a square wave. 
            delayMicroseconds(2000); //Wait 2000 microseconds
          digitalWrite(StepPins[TargetNumber], LOW); //Look up the step pin for the current motor in the step pins array (StepPins) and set it LOW to create a falling edge on a square wave.
          delayMicroseconds(2000); //Wait 2000 microseconds
        }
}

void RetractTarget (int TargetNumber){

//Retract the selected target by spinning the relevant motor clockwise

        // Set the spinning direction for the selected motor to clockwise:
        digitalWrite(DirPins[TargetNumber], LOW);  //Look up the direction pin for the current motor in the direction pins array (DirPins) and set it LOW for anti-clockwise motion

        // Spin the stepper motor 90 degrees:
        for (int i = 0; i < StepsPerRevolution/4; i++) {
          // These four lines result in 1 step as the stepper motor steps on the rising edge of a digital wave - Transition from Low to High:
          digitalWrite(StepPins[TargetNumber], HIGH); //Look up the step pin for the current motor in the step pins array (StepPins) and set it HIGH to create a rising edge on a square wave.
            delayMicroseconds(2000); //Wait 2000 microseconds
          digitalWrite(StepPins[TargetNumber], LOW); //Look up the step pin for the current motor in the step pins array (StepPins) and set it LOW to create a falling edge on a square wave.
          delayMicroseconds(2000); //Wait 2000 microseconds
        }
}