ESP8266

The ESP8266 can be likened to an mini Arduino with Wifi capabilities.

• It has just enough memory and processing power to handle a few tasks while communicating back and forth with other devices over WiFi.
• It has a limited number of IO pins
• It runs both 3.3v and 5v
• It can connect via USB or simply draw it power from a USB port.
• It can be used to take sensor readings or switch a relay - all remotely.
• Best thing is, they run about $8 each!

Example Data Flow Diagram