/*
 - Raspberry Pi Pico W + two DS18B20 sensors + status LED
  • Built-in error check on readTemp() → GUI only sees valid data
  • When overrideActive==true → tempThreshold logic is bypassed
  • Outputs every 1 s: mean;t1;t2\n
  • Accepts single-byte commands: '1'→LED ON, '0'→LED OFF
 */
            
#include <microDS18B20.h>       // DS18B20  MicroMicro library

// Pins Definition
MicroDS18B20<26> sensor1;       // DS18B20 on GPIO 26
MicroDS18B20<27> sensor2;       // DS18B20 on GPIO 27
#define LED_PIN 22              // status LED 

// Temperature Threshold
const float tempThreshold = 23.0;   // auto-LED ON above this mean °C

// Set-up 
void setup() {
  Serial.begin(9600);           // baudrate should match the Processing sketch
  pinMode(LED_PIN, OUTPUT);
}
// Global variables
bool overrideActive = false; //initially OFF
bool overrideState  = false;

void loop() {
  // Process any incoming 1s/0s commands immediately 
  while (Serial.available()) {
    char c = Serial.read();
    if (c == '1') {
      overrideActive = true;
      overrideState  = true;
    }
    else if (c == '0') {
      overrideActive = true;
      overrideState  = false;
    }
    // ignore anything else
  }

  // Kick off conversions 
  sensor1.requestTemp();
  sensor2.requestTemp();
  delay(1000);                // wait for the DS18B20 sensor

  // Read temperature values and compute mean 
  bool ok1 = sensor1.readTemp();
  bool ok2 = sensor2.readTemp();
  if (ok1 && ok2) {
    float t1 = sensor1.getTemp();
    float t2 = sensor2.getTemp();
    float meanT = 0.5 * (t1 + t2);

    // apply LED logic with override 
    if (overrideActive) {
      digitalWrite(LED_PIN, overrideState ? HIGH : LOW);
    } else {
      digitalWrite(LED_PIN, meanT >= tempThreshold ? HIGH : LOW);
    }

    // send CSV line 
    Serial.print(meanT, 2); Serial.print(';');
    Serial.print(t1,     2); Serial.print(';');
    Serial.println(t2,   2);
  }

  // loop back and wait for next command!
}