This articles describes how you can use I2C (TWI) communication, Arduino and temperature sensors to measure 3 different temperatures. It can be very helpful when you want to measure the outside, ...

In this quick Arduino tutorial I will explain how you can control a relay using the Arduino Board, one 1K and one 10K resistors, 1 BC547 transistor, one 6V or 12V relay, one 1N4007 diode and a 12V fan ...