Tonight I’m making a little Arduino mains relay timer. It’s for the box fan in my room. The timer built into the fan broke years ago but even before it did, the ticking noise was distracting when trying to go to sleep! But leaving it on all night means I wake up extra dehydrated. Hence, an electronic 2-hour timer for my fan.
Here's the code. (not yet tested tho!)
It compiles to 1222 entire bytes and uses a whole 10 bytes of RAM! I love embedded processors