#define trig      PB6
#define echo      PB1

#define LED_BUILTIN PB3
#define ORANGE_LED  PB7
#define RED_LED     PB0
#define buzzer      PA8

#define DS    PA0   // Data
#define SH_CP PA1   // Clock
#define ST_CP PA3   // Latch
#define MR    PA4

#define SWITCH_PIN PB4

long duration;
float distance;
unsigned long lastBipTime = 0;

// Table de vérité pour afficheur 7 segments (ajustée selon votre définition)
const byte numbers[] = {
  0x7E, 0x0A, 0xB6, 0x9E, 0xCA, 0xDC, 0xF8, 0x0E, 0xFE, 0xCE
};

void setup() {
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(ORANGE_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(SWITCH_PIN, INPUT_PULLUP);
  
  pinMode(DS, OUTPUT);
  pinMode(SH_CP, OUTPUT);
  pinMode(ST_CP, OUTPUT);
  pinMode(MR, OUTPUT);

  digitalWrite(MR, HIGH); // Désactive le Reset du registre [cite: 212]
  
  Serial.begin(115200);
  Serial.println("Hello, STM32!");
}

void loop() {
  // Le système ne fonctionne que si l'interrupteur est actionné (LOW) [cite: 13, 43]
  if (digitalRead(SWITCH_PIN) == LOW) {
    
    // 1. Mesure de la distance [cite: 24]
    digitalWrite(trig, LOW);
    delayMicroseconds(2);
    digitalWrite(trig, HIGH);
    delayMicroseconds(10);
    digitalWrite(trig, LOW);

    duration = pulseIn(echo, HIGH);
    distance = (duration * 0.0343) / 2;

    Serial.print("Distance: ");
    Serial.print(distance);
    Serial.println(" cm");

    // 2. Gestion de la signalisation visuelle et sonore [cite: 44, 45, 46, 48]
    if (distance > 120) {
      digitalWrite(LED_BUILTIN, HIGH); // Vert [cite: 44]
      digitalWrite(ORANGE_LED, LOW);
      digitalWrite(RED_LED, LOW);
      noTone(buzzer);
    } 
    else if (distance >= 30) {
      digitalWrite(LED_BUILTIN, LOW);
      digitalWrite(ORANGE_LED, HIGH); // Orange [cite: 45]
      digitalWrite(RED_LED, LOW);

      // Calcul de l'intervalle linéaire (1s à 120cm, 0s à 30cm) 
      int interval = map(distance, 30, 120, 0, 1000);
      if (millis() - lastBipTime >= interval) {
        tone(buzzer, 440, 100); // Bip 440Hz [cite: 49]
        lastBipTime = millis();
      }
    } 
    else {
      digitalWrite(LED_BUILTIN, LOW);
      digitalWrite(ORANGE_LED, LOW);
      digitalWrite(RED_LED, HIGH); // Rouge [cite: 46]
      tone(buzzer, 440); // Bip continu 
    }

    // 3. Affichage sur les deux 7 segments [cite: 40, 47]
    float distM = distance / 100.0;
    if (distM > 9.9) distM = 9.9;
    
    int tens = (int)distM;
    int units = (int)(distM * 10) % 10;

    // Préparation des octets (Point décimal sur le premier digit) 
    byte tensData  = numbers[tens] | 0x01; 
    byte unitsData = numbers[units];

    digitalWrite(ST_CP, LOW);
    shiftOut(DS, SH_CP, MSBFIRST, unitsData); // Second registre [cite: 41]
    shiftOut(DS, SH_CP, MSBFIRST, tensData);  // Premier registre [cite: 41]
    digitalWrite(ST_CP, HIGH);

  } 
  else {
    // Mode veille : tout éteindre [cite: 43]
    digitalWrite(LED_BUILTIN, LOW);
    digitalWrite(ORANGE_LED, LOW);
    digitalWrite(RED_LED, LOW);
    noTone(buzzer);
    
    digitalWrite(ST_CP, LOW);
    shiftOut(DS, SH_CP, MSBFIRST, 0x00);
    shiftOut(DS, SH_CP, MSBFIRST, 0x00);
    digitalWrite(ST_CP, HIGH);
  }

  delay(50); // Simulation plus fluide
}