const float BETA = 3950; // Beta Coefficient of the thermistor
void setup() {
Serial.begin(9600);
pinMode(3, OUTPUT);
pinMode(5, OUTPUT);
}
void loop() {
int analogValue = analogRead(A0);
// Avoid division by zero
if (analogValue > 0) {
float celsius = 1 / (log(1 / (1023.0 / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;
// Print temperature to Serial Monitor
Serial.print("Temperature (°C): ");
Serial.println(celsius);
// Check if temperature is in the range 20 to 25
if (celsius > 20 && celsius < 25) {
digitalWrite(3, HIGH); // Turn green LED on
digitalWrite(5, LOW); // Turn red LED off
} else {
digitalWrite(5, HIGH); // Turn red LED on
digitalWrite(3, LOW); // Turn green LED off
}
} else {
Serial.println("Invalid analog value.");
}
delay(1000); // Wait 1 second before repeating
}