This project refers to an Arduino sketch that implements a simple fire alarm using a temperature sensor, a piezo speaker and one LED as indicator for deaf-mute cases. The alarm checks every second if there is enough room temperature (via the temperature sensor). If there is enough temperature to consider it a fire burning in that place, then the alarm produces a musical tune with the piezo speaker and lights the LED indicator. Otherwise, both the speaker and the LED indicator remain in state OFF.

For more information, you can get the project itself: