Step 1: Parts
- An Adafruit Neopixel Ring - this is a 1.75" ring of 16 digitally controllable RGB LEDs.
- An Arduino Uno, or similar. The nice thing about an Uno is that there is a 5v regulator you can use to power the LEDs, but with one of the smaller Arduino boards, you can use an external 5v power supply to drive the LEDs and the board. Arduinos can be found at many places like Amazon, or lower cost clones can be found on AliExpress. The Adafruit Trinket would probably work well for this project too.
- (3) pieces of solid core wire, each 7" long. 22 gauge is better, but 20 gauge just fits in the sockets too. Different colors for +5v, Gnd, and Data would be nice, but not necessary.
Power can come from a wall adapter for the Arduino (6v dc - 12v dc, where lower is preferred), or the USB port. For a remote location, you can use a 9v battery clip with a 2.1mm ID plug. A battery will not last long, though, depending on how many LEDs you have on over time.
Step 2: The Papercraft Base
It is easier to first fold the paper back (a "mountain" fold) on the two long vertical folds on each side of the mantle. Then fold it back before cutting the paper. That way, all the individual folds are already creased.
Note that there are some very short cuts above and below the fireplace to enable folding on those creases.
Cut out the stockings below the mantle carefully with a sharp knife.
For the horizontal folds, some are inward and some outward - see the pictures to see which is which.
Gluing the large areas first is best. I used white glue, which dries fast if you smooth the glue out with your finger before gluing. The bottom large tabs fit against the fold between the fireplace and the wall. The large tabs on top line up with the outside edge of the wall.
On the wreath, there are three small dots - punch those out with a push pin - those are where the three wires from the LED ring will go.
Step 3: LEDs and Wiring
The Neopixel ring has three wires to solder: +5, Gnd, and Data In - we are using the Arduino 5v regulator to drive the LEDs. You will not need the data out pin for this project. You will need three pieces of 20 gauge solid core wire, 7" each. Strip the insulation off one end for the ring at about 3/8", and the end for the Arduino at about 1/4". The 20 gauge solid core wire fits nicely into the header sockets.
Note: Solder from the bottom of the board - not the LED side! The holes are through-plated, so the solder will flow up. Trying to solder on the LED side may damage the solder to the LEDs. This is a bit unusual, soldering from the back with the wire sticking out there also, but if you put the wire in the hole just enough to go through, there should be some bare wire that you can solder to. The extra wire exposed on the back is not an issue since there are no other wires close to each hole. I found it easy to lay the ring LED side down, then bent the wire so it fit in the hole and rested on the table, allowing it to stay in place while soldering.
Run the wires through the holes in the wreath (use a push pin to start the holes), To hold the wreath in place, either bend the wires behind the wreath, or use a bit of glue or tape as needed.
Connect the +5 and Gnd wires from the LED ring to the corresponding Arduino pins. Connect the LED data in pin to digital pin 6 on the Arduino. You can use a different i/o pin - would just need to change the code to use the right pin.
Each WS2812 LED+driver can draw about 60 mA when all three colors are on full (white), so if all 16 LEDS are on full, the ring will use 960mA. The Arduino Uno regulator is rated for 1 amp, but will likely thermally shut down with that much current being drawn, especially for higher voltages being supplied to the board (since the excess energy is dissipated as heat). Also, when supplied by USB, the usable current will be more like 400 mA. The good news is that the LEDS will almost never all be on full at the same time, and since they are so intense, you will want to dim them down a lot more than fully on.
If you need more power, you can use an external 5 amp power supply and use that to power both the LEDs and the Arduino.
Step 4: Arduino Programming
Enjoy, and if you come up with some nice animations, share them! Happy Holidays!