He decided to take an in-depth look at the DHT11 sensor; which you can get your hands on for under $3 if you know where to look. The four-pin device uses a 1-wire protocol. [Rajendra] discusses ...

A quick search suggests the utterly ubiquitous DHT11, which speaks a well documented protocol and has libraries for every conceivable microcontroller and platform. Plug that into your Arduino and ...