In a previous example we showed you a basic usage of a DS18B20 which outputted the temperature to the Serial output.
A simple addition to the code can show a practical example, in this case if the temperature exceeds a certain value then a message is displayed. In real life this could be an alarm of some direction.
Code
#include <OneWire.h> #include <DallasTemperature.h> //the pin you connect the ds18b20 to #define DS18B20 2 OneWire ourWire(DS18B20); DallasTemperature sensors(&ourWire); void setup() { Serial.begin(9600); delay(1000); //start reading sensors.begin(); } void loop() { //this sets the max temp int maxTemp = 30; //read temperature and output via serial sensors.requestTemperatures(); //if temperature exceeds maxTemp value if(sensors.getTempCByIndex(0)>maxTemp) { Serial.println("DANGER"); } else { Serial.print(sensors.getTempCByIndex(0)); Serial.println(" degrees C"); } }