The [Libelium] team wanted to help people in Japan measure radiation in their surroundings following the nuclear accident in Fukushima. Because of the affordability and seeming ubiquity of the Ardu… ...

Both the Arduino Nano and Uno can be powered via their integrated USB connectors. This automatically supplies regulated 5V power to the board, allowing you to use any USB-supported power source ...

The build relies on an Arduino Uno as the brains. ... [Maker 101] gave the Arduino an infrared sensor which can pick up signals from a simple IR remote control.

The Arduino UNO R4 boasts a 3x performance increase over the UNO R3 and , in addition, SRAM has been upgraded from 2kB to 32kB, and flash memory from 32kB to 256kB to support more complex projects.