Leaving the PIR sensor and the ESP8266 microcontroller (an Adafruit Huzzah) on all the time drained the batteries pretty quickly, so [rgrokett] decided to try putting the Huzzah to sleep.

Present consists of just a PIR sensor and Arduino in a 3D printed enclosure to snap onto your monitor.

The PIR module actually consists of a pyroelectric sensor (looks like an old metal transistor with a black window on the top), which generates energy when exposed to heat, and it’s tied in closely ...