This Arduino BASIC interpreter will make a really fun one-day project if you’ve already got the parts on hand. [Usmar A. Padow] put together an Arduino Uno, SD card, four line character LCD, and ...

To build this project, all you need is three main components: an Arduino Uno, a 16x2 LCD, and a push button. You can connect everything to a breadboard to keep it simple.

No multimeter handy (for shame)? Well, as it turns out you can actually measure capacitance using your Arduino Uno, with no external components, and only ~20 lines of code.