This build is about using the temperature sensor in your clock. The ATMega328p, the chip at the heart of all your Arduino Uno clones, has within it a watchdog timer that clicks over at a rate of ...

Hardware Using Arduino UNO and a NANO with ENC28J60 ethernet shield. Pins 13, 12, 11, and 10 are reserved for the ethernet shield and are connected to the Arduino UNO at the same pins.