// Pin configuration of Ultrasonic Distance sensor
const int triggerPinFoot = 9; // Trigger Pin
const int echoPinFoot = 8; // Echo Pin

const int triggerPinHand = 7; // Trigger pin of hand sensor
const int echoPinHand = 6; // Echo pin of hand sensor

const int speakerPin = 11; // Speaker Pin

// Frequency parameters (reflashable)
const int minFrequency = 220; // Min Frequency
const int maxFrequency = 4400; // Maximum frequency

void setup() {
  // Set pin modes
  pinMode(triggerPinFoot, OUTPUT);
  pinMode(echoPinFoot, INPUT);
  
  pinMode(triggerPinHand, OUTPUT);
  pinMode(echoPinHand, INPUT);
  
  pinMode(speakerPin, OUTPUT);
}

void loop() {
  // Get distance for volume control (Right Foot)
  int distanceFoot = getDistance(triggerPinFoot, echoPinFoot);
  int volume = map(distanceFoot, 1, 100, 0, 255); // Mapping 1-100 cm to PWM 0-255
  
  // Get distance for frequency control (Right Hand)
  int distanceHand = getDistance(triggerPinHand, echoPinHand);
  int frequency = map(distanceHand, 1, 100, minFrequency, maxFrequency); // Mapping 1-100 cm to 220-4400 Hz
  
  // Generate PWM tone
  tone(speakerPin, frequency, 50); // 50 ms duration per cycle
  
  // Control volume
  analogWrite(speakerPin, volume);
  
  delay(100); // wait for 100 milliseconds
}

int getDistance(int triggerPin, int echoPin) {
  // This function will receive trigger and echo pin as input
  // Clear the trigger pin
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  
  // Set the trigger pin HIGH for 10 microseconds
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  
  // Read the echo pin
  long duration = pulseIn(echoPin, HIGH);
  
  // Calculate distance (in cm)
  int distance = duration * 0.0344 / 2;
  
  return distance;
}