Smart Sound Boom Controller 

#include <AccelStepper.h>

// === Stepper setup ===

const int dirPin = 9;

const int stepPin = 8;

const int motorInterfaceType = 1; // Using DRIVER mode (A4988)

AccelStepper stepper(motorInterfaceType, stepPin, dirPin);

const int stepsPerRevolution = 6400;

const float degreesPerStep = 360.0 / stepsPerRevolution;

// === IR sensors (blind area detection) ===

const int sensor1Pin = 11; // 0° sensor

const int sensor2Pin = 12; // 30° sensor

// === Motion parameters ===

const int maxSpeed = 400;     // steps/second

const int accel = 100;        // steps/second^2

const int red_led = 2;

const int green_led = 3;

const int homing_btn = 4;

// === Variables ===

int switchPins[6] = {A0, A1, A2, A3, A4, A5};

int switchValue[6];

int positionAngles[7] = {0, 30, 90, 160, 230, 290, 340};

// 0 = auto-home reference (30° sensor)

// 1-6 = safe positions

long targetPosition = 0; // in steps

bool homed = false;

int currentPosition;

int prevPosition;

int iterate = 0; // this variable is to detect if there is more one reading from switch for long time then it's autohome position

void setup() {

  Serial.begin(9600);

  // define switch pins

  for (int i=0; i<6; i++) {

    pinMode(switchPins[i], INPUT_PULLUP);

  }

  pinMode(sensor1Pin, INPUT);

  pinMode(sensor2Pin, INPUT);

  pinMode(green_led, INPUT);

  pinMode(red_led, INPUT);

  pinMode(homing_btn, INPUT_PULLUP);

  stepper.setMaxSpeed(maxSpeed);

  stepper.setAcceleration(accel);

}

void loop() {

  // === Test switch ===

  for (int i=0; i<6; i++) {

    switchValue[i] = digitalRead(switchPins[i]);

  }

  // check if all pin are HIGH for 200 millis then autohome

  int pinCounter = 0;

  int actualSwitchPos = NULL;

  // set previous position

  if(actualSwitchPos != currentPosition){

    prevPosition = currentPosition;

  }

  for (int i=0; i<6; i++) {

    if(switchValue[i] == LOW){

      pinCounter ++;

      actualSwitchPos = i+1;

    }

  }

  if(pinCounter == 1 && homed && actualSwitchPos != currentPosition){

    moveToPosition(actualSwitchPos);

    iterate = 0;

  }

  else if (pinCounter == 1 && !homed && actualSwitchPos != currentPosition) {

    autoHome();

    moveToPosition(actualSwitchPos);

    iterate = 0;

  }

  else if (pinCounter == 0) {

    iterate ++;

  }

  // if the button pressed then autohome

  if(digitalRead(homing_btn) == LOW){

    autoHome();

  }

  // if a number bigger than 6 is selected in the switch then autohome

  if(iterate >= 10 && !homed){

    iterate = 0;

    autoHome();

  }

  // === Keep running stepper motion if moving as long as no sensor reading ===

  if(checkSensors() == 0)

    stepper.run();

}

// ===============================================

// Move to selected safe position

// ===============================================

void moveToPosition(int posNum) {

  currentPosition = posNum;

  int angle = positionAngles[posNum];

  targetPosition = angleToSteps(angle);

  Serial.print("Moving to position ");

  Serial.print(posNum);

  Serial.print(" (");

  Serial.print(angle);

  Serial.println("°)");

  stepper.setSpeed(500);

  stepper.moveTo(targetPosition);

  while (stepper.distanceToGo() != 0) {

    stepper.run();  // uses acceleration & target position

    // power green LED & turn off red led

    digitalWrite(red_led, LOW);

    digitalWrite(green_led, HIGH);

    int sensors = checkSensors();

    if (sensors == 1 || sensors == 2 && currentPosition-prevPosition < 0) { // any sensor active → stop

      Serial.println("⚠️ Blind zone detected! Stopping...");

      stepper.stop();

      autoHome();

      break;

    }

  }

  // power green LED & turn off red led

  digitalWrite(red_led, HIGH);

  digitalWrite(green_led, LOW);

  homed == false;

  Serial.println("✅ Position reached.");

}

// ===============================================

// Auto-home routine (move until sensor2 triggers)

// ===============================================

void autoHome() {

  Serial.println("🏠 Auto-homing...");

  // power green LED & turn off red led

  digitalWrite(red_led, LOW);

  digitalWrite(green_led, HIGH);

  // if it's already infront of the sensor go away then return back to the sensor

  if (checkSensors() == 2){

    // go away the sensor

    stepper.setSpeed(100);

    while (checkSensors() == 2) {

      stepper.runSpeed();

    }

    // then return back

    autoHome();

  }

  else{

    stepper.setSpeed(-400);

    while (checkSensors() != 2) {

      stepper.runSpeed();

      if(checkSensors() == 2){

        break;

      }

    }

  }

  stepper.stop();

  // delay(100);

  // Set current position = 30° reference (home)

  stepper.setCurrentPosition(angleToSteps(30));

  currentPosition = 1;

  homed = true;

  // power green LED & turn off red led

  digitalWrite(red_led, HIGH);

  digitalWrite(green_led, LOW);

  Serial.println("✅ Homing complete. Home = 30°");

}

// ===============================================

// Convert angle to steps

// ===============================================

int angleToSteps(int angle) {

  return angle / degreesPerStep;

}

int checkSensors(){

  // === Safety check: stop if IR sensors detect the blind zone ===

  if (digitalRead(sensor1Pin) == HIGH && digitalRead(sensor2Pin) == HIGH) {

    return 3;

  }

  if (digitalRead(sensor2Pin) == HIGH) {

    return 2;

  }

  if (digitalRead(sensor1Pin) == HIGH) {

    return 1;

  }

  return 0;

}