You also need to select the transistor by the type of fan that you use. In my case I used the well-known BD139 transistor and a 9V battery to provide power to the fan and transistor. The LM35 ...

Posted in Arduino Hacks, Lifehacks Tagged 9V battery, arduino, arduino nano, IR temperature sensor, leds, lever switch, limit switch Smart Coaster Informs You When Your Drink Is Ready December 4 ...

As you can see from that sketch and the circuit diagram, the LED is connected to the digital pin 13 of the Arduino. Once you verify (compile) the sketch and upload it to the Arduino board, you should ...