There’s not much time left now. If you’re going to put something together to give the youngsters some night terrors in exchange for all that sweet candy, you better do it quick. This late to the game ...

It is a pretty common first project to use an Arduino (or similar) to blink an LED. Which, of course, brings taunts of: you could have used a 555! You can, of course, also use any sort of oscillator, ...

Before opening the Arduino software, wire up the Arduino according to the circuits page using the 8MHz minimalist breadboard circuit but with a 10k pull-up resistor on the reset pin (physical pin 1).