This is my second attempt at a tree shaped PCB for my learn to solder classes. This one uses regular through-hole LEDs instead of the surface mount Neopixels I used in the first design. I again used an ATtiny85 MCU on this board. To get 12 LEDs flashing independently with so few pins I had to use the "Charlieplex" technique. I again found my inspiration over on the Technoblogy website for the LEDs and the buzzer music. I had to do a little work on the timers to get the combined code to work together but it turned out well.
This will be a nice board for my "Learn to Solder" classes. I went with USB power (the cord costs less than batteries) and 3D printed stands to display the finished board.
I did a few videos on the design. Here is the playlist.