LED Christmas tree - Learning Electronics
Posted by dapj20 on Jan 04, 2016 in Christmas-Crafts
Letter from Chris of PyroElectro.com in 2013 - Happy Holidays! Here's a project I know your readers will love! It's an all-digital-hardware LED Christmas tree we're calling the Christmas Tree O'Digital Logic.
The tree itself is composed of 64 LEDs built into a spiral sitting on a piece of protoboard. Underneath, the controller uses shift registers and a 555 timer to create two modes of display: a predictable pattern and a random pattern. This should light up any desk or shelf and bring merriment to your readers!
To build the tree, we'll use 63 green LEDs and 1 red LED. Lots of wire will be needed to make the spiral + cone shape of LEDs from top to bottom. To build a random pulse generator, we'll use some digital logic trickery with a 7404 hex inverter. A 555 timer will be used to drive 8 shift registers, which will control all 64 of the LEDs. Finally, a 4 bit timer should be thrown into the circuit in case we want to slow things down with a divider.