Introduction: Reusing Old LED Christmas Decorations by Remixing Them
I bought a rather hideous Christmas decoration in a Pound shop (i.e. dollar store) during the after season sales three years ago. It was an underwhelming "NOEL" sign that was illuminated by an insufficient number of battery powered LEDs. There were lots of these signs left over going for half price (50p) -- they didn't sell that well at all. I had also bought a set of indoor meteor shower effect LED lights at the sales in another store. This year I had an idea of how I might combine these two decorations to create a fresh new look and feel of that very unpopular light-up sign.
Although these instructions are specific to the LED sign and decorations that I'm remixing, they should be fairly straightforward to adapt for similar decorations that you might already have acquired in seasons past.
There is no programming involved because we will be reusing the microcontrollers in the meteor shower lights which come pre-programmed.
- A hideous LED Christmas sign from Poundland
- Meteor shower LED decoration
- Spare Christmas LED string - preferably the same colour as the sign
- White cardstock
- Silver reflective wrapping paper, or aluminium foil
- Lithium polymer battery or 3 AA batteries with battery holder
- JST battery connector (optional)
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Step 1: Disassemble the LED Sign
This NOEL sign has 8 warm white LEDs. It definitely needs a few more than that. Also they don't blink, and are positioned very poorly to illuminate the word properly or evenly.
- Remove the screws that hold the back plate and battery compartment
- Cut the wires to the battery holder - we will not be using the holder
- Remove any hot melt glue holding the LEDs to the sign. There is no need to use a heat gun. Just pull sharply with pliers. Don't worry about damaging the warm white LED string as we won't be using them
Step 2: Drill New Holes
Examine the placement of the holes and mark where the sign needs more of them.
- Drill new holes in the sign with a rotary tool or hand drill
- Check whether the string of red LEDs will fit in the holes
- Widen the holes using the drill as needed
Step 3: Prepare the Meteor Shower Light PCB
If you jumped on the meteor shower light craze a few years ago, you probably have a set of these decorations in storage that are broken or damaged. Although the LEDs may not all be lighting up, the microcontroller (that 8 pin chip on each meteor) is likely still in working order. By reusing this microcontroller instead of an Arduino, we save ourselves the effort of doing any embedded programming.
- Find one of the meteor shower elements that seems to be mostly working. Make note of the polarity of the wires that power that meteor element.
- Detach it from the rest of the string. Examine the PCB to check whether the polarity of each LED is clearly marked. You will either see a "+" or a diode symbol.
- If you find no such markings you will need to use a multimeter to check the polarity of each LED, or examine the LED internal structure (the anvil shape is the cathode). Make a note of the polarity of each LED.
- Desolder all the LEDs. You actually only need to do as many as there are holes that were in the sign, and then saw through the PCB to cut off the remainder. Fortunately I'm using a 10 LED meteor light and my sign has 10 drilled/widened holes.
- Cut 10 red LEDs from the spare LED string, making sure each LED has sufficient length of wire attached. Strip and tin the ends of each wire with solder.
- Solder the red LEDs into the vacant positions of the meteor shower PCB. Pay close attention to the polarity. Make sure it matches that of each LED that you desoldered.
- Test the newly wired up PCB using 3-5V DC supply - 3 AA batteries should work. Again pay close attention to the polarity when hooking up to power.
Step 4: Install the Red LEDs in the Sign
- Insert each red LED in one of the holes in the sign. The order does matter. I arranged the LEDs in roughly left to right order - the same direction as you'd be reading the word "NOEL"
- You might need to add some glue around each LED to prevent them falling out of the holes when you turn the sign over
Step 5: Create Sign Mask With Reflective Backing
- On a white piece of card stock, trace the outline of the sign
- Within this outline, draw the boundaries of the letters of the sign, but offset by about 4mm inward from the previously traced outline. These letters should now form a slimmer version of those on the sign
- Cut out these slimmed letters
- Cut a rectangle of reflective wrapping paper or foil that is roughly the same size as the cardboard letters
- Using double sticky back tape or glue, attach the foil to the back of the slimmed cardboard letters
- Trim the reflective foil to match the shape of the slimmed letters
- Use double sticky back tape to attach the letters to the front of the sign. Note that the reflective side faces down to help redirect the LED light towards the edges of the sign. The intention is to illuminate the word NOEL as a silhouette.
Step 6: Powering the LEDs
The sign came with its own battery holder but it only used 2 AAAs which is insufficient to drive the meteor shower microcontroller and 10 LEDs. Instead we shall replace this with a lithium polymer battery.
- Solder a JST battery connector to the V+ and Ground of the PCB. Pay attention to the polarity of the connector when doing this.
- Saw the sign's back plate into 3 parts and discard the AAA battery holder. Screw the remaining pieces to the back of the sign.
- Use double sticky back tape and a strip of cardboard to create a rudimentary pocket for a lithium polymer battery
- Install and connect up the lithium polymer battery.
Alternatively you might instead solder the battery or a 3xAA battery holder directly to the PCB using wires.
I'm using one of those "disposable" PowerHits that were selling in the convenience stores a while ago. I've modified this one so that it can be recharged and reused. The instructions on how to do this go beyond the scope of this guide. See the details in the related video. So 4 separate items are being reused in this project!
Step 7: Completed Remixed Christmas Decoration
A fresh unique Christmas decoration has now been created by reusing components from 3 old ones!
Place this in the window or on a shelf. It looks best when viewed in dim or subdued lighting.
Participated in the