If you’ve messed with Arduino, the inexpensive micro controller ... but it’s a great idea for folks who might want to add a little high voltage to their DIY products. It has 250V / 5A Relays ...

It uses an Android device to switch an LED driven by the Arduino. Connectivity is provided ... Instead he’s showing off the power of App Inventor to get your Android controls up and running ...

The code (Arduino sketch) allows push button increment of the counter from 0 to 9. The whole circuit can be powered from a standard 9V PP3/6F22 battery, or from any suitable Arduino power adaptor ...