Bitlash

Learning to code an Arduino can be pretty confusing as most calculations will occur ‘behind the scenes’ of a sketch. Bitlash could help provide some quick answers for testing/learning –

Bitlash is a command line shell for the serial port. It runs on Arduino and interprets
commands that you type.

It is intended for those occasions when you need to bang some bits but writing a
full Arduino sketch is overkill.

[…]

Bitlash interprets a tiny language that lets you call the familiar Arduino C functions (though some names have been abbreviated a bit). For example, to analogRead pin 3 and print the result divided by four, you could say to bitlash:
> print(a3/4, "degrees")
102 degrees

Very cool – this should prove quite useful. – Bitlash