The Ugly Electric Christmas Sweater
David Christianson
Tree Components
1 - Control Board (See Schematic and Parts List)
1 - Tacky Christmas Tree Sweater
1 - 9x14 inch Green Sparkly Self Adhesive Craft Foam Sheet
1 - 8.5x11 inch Black Craft Foam
1 - 8.5x11 inch Printer paper
2 - Martha Stewart 36-Light LED Warm Battery Operated Christmas Light String
8 - Neodynium Iron Boron Magnets (3/8 Dia x 1/16 thick)
1 - Red Tinsel Garland
1 - Red Bead Garland
2 - Low temperature Hot Glue Sticks
Solder as needed
Heat Shrink Tubing as needed
Tools
Low temperature hot glue gun
Soldering Iron
Hot air gun to shrink tubing
Control Board
Using your favorite handbuilding technique construct the control board to the schematic and Electronics parts list on a development board (for example: PICKIT 2 LOW PIN COUNT DEMO BOARD, Mfr. Part#: DM164120-1, Allied Stock#: 70046062).
Firmware for the control board has been included for download on the project webpage.
Create the Racing Light String
The racing light effect is achieved by sequencing from four LED co-located strings to make it appear that the light is traveling along the string.
1.) Carefully unwind the 36 light strings and cut them free from the battery pack. Assure that you leave plenty of extra wire to work with.
2.) Divide each string into two equal lengths with 18 LEDs per string and cut them.
3.) Using the battery pack and a resistor, determine the polarity of each string. Mark the negative wire with a black permanent marker for later.
4.) Carefully twist the four LED strings together making sure that the LEDs of each string are evenly spaced. You should have slightly less than 4.5 ft of string when you are finished. The string is solid wire so be gentle with it, avoiding excess bending of the wire.
5.) Using heat shrink tubing and stranded hookup wire, connect the LED string to the control board, using the black marks to control polarity. Heat shrink should be applied to all wire-to-wire connections to avoid shorts.
6.) Connect wires to the momentary push button and connect it to the control board.
7.) Cut the positive battery holder wires and wire in the master power switch as shown. This connection insures a hard reset when the device is powered off an on. This switch is not required but will eliminate current drain in the off position. Connect the battery holder to the control board.
8.) Insert batteries into the holder and check function of the string.
9.) Apply hot glue to all wire to PCB connections at the PCB after soldering to strain relieve.
Build the Tree
1.) Trace a pattern of a Christmas tree on the green craft foam and cut it out. Leave at least four LEDs at the top in a cluster for the star on the apex of the tree, then hot glue the light string in a serpentine pattern over the tree.
2.) Cut a star shape from the printer paper and glue it on top of the four LEDs at the top of the tree.
3.) Decorate the tree with the beads cut from the bead garland and the red tinsel garland, this is a great chance to be creative.
4.) Cut a double-sided tree trunk from the black craft foam. Fold it over the pushbutton and hot glue it closed. Attach the trunk to the bottom of the tree with hot glue. Squeezing this will activate the tree and change the flash sequence.
5.) Hot glue the control board, battery pack, and master on/off switch to the back of the tree as shown.
6.) Glue the magnets at the top, middle, and bottom flanks of the back of the tree shape. To apply the effect to the sweater simply hold the tree against the sweater and apply a magnet to these glue magnets from inside the sweater. The magnetic clamping force will hold the effect in place for a night of tacky Christmas sweater parties.
7.)To operate the sweater, operate the master switch to the on position and press the momentary button in the tree stump until the flash sequence is to your liking.