E21Q3

// Pin assignments for Wheatstone Bridge output
const int bridgeOutputPin1 = A0; // Point A of the Wheatstone Bridge
const int bridgeOutputPin2 = A1; // Point B of the Wheatstone Bridge

// RTD and bridge configuration constants
const float referenceResistance = 100.0; // 100 ohms at 0°C for Pt100 RTD
const float tempCoefficient = 0.385; // Ohms per °C for Pt100

void setup() {
  Serial.begin(9600); // Start serial communication at 9600 bps
}

void loop() {
  // Read analog values from the Wheatstone Bridge points
  int sensorValueA = analogRead(bridgeOutputPin1);
  int sensorValueB = analogRead(bridgeOutputPin2);

  // Convert the analog readings to voltage
  float voltageA = sensorValueA * (5.0 / 1023.0); // Convert A0 reading to voltage
  float voltageB = sensorValueB * (5.0 / 1023.0); // Convert A1 reading to voltage

  // Calculate the differential voltage output of the bridge
  float voltageDifference = voltageA - voltageB;

  // Calculate the resistance change in RTD based on voltage difference
  float rtdResistance = referenceResistance + (voltageDifference * referenceResistance / 5.0); // Assume bridge is balanced at 0°C

  // Calculate the temperature from the RTD resistance
  float temperature = (rtdResistance - referenceResistance) / tempCoefficient;

  // Output the temperature to the Serial Monitor
  Serial.print("Temperature: ");
  Serial.print(temperature, 2); // Print with 2 decimal places for clarity
  Serial.println(" °C");

  delay(1000); // Delay for 1 second between readings
}