I created my 2016 Yuletide Ornament as a gift for my family and friends. I designed, developed, sourced, and assembled (by hand) 25 of these Christmas ornaments in November and December 2016 - I have been wanting to do something like this for years, but this is the first time inspiration struck a month ahead of time instead of a week before Christmas. The ornament itself is 3 by 4 inches in the shape of a Christmas tree, and has 4 banks of 5 LEDs each (2 red, 2 green), which are driven by all discrete logic and powered by 2 AAA batteries, which can be switched off and last about 90 hours (continuous usage).
The circuit consists of the batteries (in series, with switch), a reverse voltage protector (diode and MOSFET), a switching boost regulator (to 3.3V), a chase generator (detailed later), and 2 banks of 5 green LEDs and 2 banks of 5 red LEDs. The chase generator consists of a 4541B programmable timer generating a 5Hz square wave, which clocks a 4022B 4-stage Johnson counter, every other output of which is connected to a channel of a 74LVTH125 buffer, which in turn drives the LEDs.