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.

A lot of people have used ESP8266 to add inexpensive WiFi connectivity to their projects, but [Oscar] decided to take it one step further and program an Arduino over WiFi with the ESP8266.