#include <OneWire.h>

// Define the pin where the DS18B20 data line is connected
#define ONE_WIRE_BUS 4 // GPIO 4 on Raspberry Pi Pico

// Create a OneWire instance
OneWire oneWire(ONE_WIRE_BUS);

void setup() {
  // Start serial communication
  Serial1.begin(115200);
  Serial1.println("DS18B20 Temperature Sensor Initialization");
}

void loop() {
  byte data[9];
  byte addr[8];

  // Search for a device on the OneWire bus
  if (!oneWire.search(addr)) {
    Serial1.println("No DS18B20 sensor detected!");
    oneWire.reset_search();
    delay(1000); // Wait for a moment before retrying
    return;
  }

  // Check if the found device is a DS18B20
  if (OneWire::crc8(addr, 7) != addr[7]) {
    Serial1.println("CRC is not valid!");
    return;
  }

  if (addr[0] != 0x28) {
    Serial1.println("Device is not a DS18B20!");
    return;
  }

  Serial1.print("Found DS18B20 with address: ");
  for (int i = 0; i < 8; i++) {
    Serial1.print(addr[i], HEX);
    if (i < 7) Serial1.print(":");
  }
  Serial1.println();

  // Start a temperature conversion
  oneWire.reset();
  oneWire.select(addr);
  oneWire.write(0x44); // Start temperature conversion

  delay(750); // Wait for the conversion to complete

  // Read the temperature data
  oneWire.reset();
  oneWire.select(addr);
  oneWire.write(0xBE); // Read Scratchpad

  // Read 9 bytes from the sensor
  for (int i = 0; i < 9; i++) {
    data[i] = oneWire.read();
  }

  // Convert the raw temperature data to Celsius
  int16_t rawTemp = (data[1] << 8) | data[0];
  float celsius = rawTemp / 16.0;

  Serial1.print("Temperature: ");
  Serial1.print(celsius);
  Serial1.println(" °C");

  // Delay before the next reading
  delay(1000);
}