Here’s a no-PCB Arduino that doesn’t obscure the DIP footprint of the AVR chip. It’s built on an ATmega88 chip, and includes a programming header, reset button, a couple of filtering caps, and an LED.

Did you know that you can use Arduino to turn on an LED when you press a button? Well, it is true, you can do this! Leaving the joke aside, let me show how you can achieve this. You will need the ...