My two twin boys are pretty into Fireman Sam these days, so the red walking car they got when they were babies got an upgrade. Four blue self-flashing LEDs, a toggle switch and a 2xAA battery holder; everything bought cheap on eBay. And voila! A fire truck with blue emergency lights.

33 high intensity LEDs are controlled with a AVR ATtiny2313 microcontroller. Four flashing patterns that can be set manually or cycle through. Uses an AVR ATtiny2313 microcontroller.