Uploaded December 2011 | Updated September 2026, 18 minutes ago
I couldn't resist a set of $.99 battery-powered LED Christmas lights at CVS, so I bought some, and then decided to create a new controller for them. There are 15 lights wired in two parallel strands, each of which drawing about 60ma at 5V. So, I used a small Atmel ATtiny13 microcontroller to control them. It reads a push button switch to decide among 4 modes, and each of its two PWM outputs drives one of the strands. I use two 2N3904s to switch the strands, and a small 7805 regulator, all mounted on a perfboard inside an Altoids case.
I couldn't resist a set of $.99 battery-powered LED Christmas lights at CVS, so I bought some, and then decided to create a new controller for them. There are 15 lights wired in two parallel strands, each of which drawing about 60ma at 5V. So, I used a small Atmel ATtiny13 microcontroller to control them. It reads a push button switch to decide among 4 modes, and each of its two PWM outputs drives one of the strands. I use two 2N3904s to switch the strands, and a small 7805 regulator, all mounted on a perfboard inside an Altoids case.
