Reader [alberto ricci bitti]‘s DVD thermometer is a temperature sensing infrared remote that controls a DVD showing the temperature. Since the box doesn’t get any feedback from the DVD player, it stops and starts the disc to make sure it is at a known state. The brain of the device is a Motorola MC68HC908QT4, an 8-pin microcontroller. Communication with the Maxim DS1621 temperature sensor I2C bus is done in software. Even if you don’t want to build a gaudy thermometer the article features a lot of interesting information. It covers reverse engineering the remote, emulating an I2C bus, and creating a programmable pulse generator instead of bitbanging.