LED Diffusion Panel - Because LED Acrylic Was Expensive to Ship

Initially I wanted to build a project using an LED panel and this LED acrylic, but it was expensive to ship: https://www.tapplastics.com/product/plastics/cut_to_size_plastic/black_led_sheet/. Instead, I used transparent black acrylic and paper to diffuse the LEDs and hide the LED panel, and I added a mask so that each LED looks like a distinct, colored spot.

1. Transparent black acrylic, e.g. https://www.amazon.com/dp/B0DJLMVD6Q
2. LED panel, e.g. https://www.amazon.com/dp/B088BTYJH6
3. Prototyping board or breadboard, e.g. https://www.amazon.com/dp/B072Z7Y19F
4. Microcontroller, e.g. https://www.amazon.com/dp/B0DJ6N55FX
5. Power supply, preferably with a screw terminal plug/tip, e.g. https://www.amazon.com/dp/B07N18XN84
6. 3D printer and knowledge of Fusion or other CAD program
7. Boxcutter to score the acrylic so you can snap it down to size (or a laser cutter)
8. Jumper wires to connect MCU to LED panel
9. Around a 330 ohm resistor
10. Around a 1000 microfarad capacitor
11. White printer paper

1. Design a 3D printed frame with grooves to insert the LED panel, acrylic, and mask
2. You do not need a separate groove for the paper diffuser. It can just slide in with the mask or acrylic
3. Also design a mask with circular (or other shape) holes in front of each LED
4. The ordering of layers should be: LED panel -> Mask with holes -> Paper diffuser -> Acrylic
5. Since the frame has long vertical arms, ensure you add diagonal trusses to maintain stability or else it will warp after printing.
6. It may take repeated attempts to get the sizes and spacings correct so that everything fits and no light leaks between the LEDs.
7. The gap between the grooves should be as small as possible. This reduces how much the LED panel can flex, which would prevent the diffused LEDs from looking uniform. This also prevents light leakage between holes in the mask.
8. A "cap"/horizontal bar closes off the top of the frame after the LED panel etc. have been inserted. I just used double-sized foam tape to hold it in place since it's not bearing any load.
9. The space behind the LED panel should be left open to allow heat to dissipate.
10. Attached example has space behind the LED panel where the MCU and prototyping board sit, and 2 slits for hooks to hold the frame up on a wall.

1. The LED panel and MCU from the Supplies list both take 5V, so they can both be connected to the power supply in parallel. The 3A power supply in the Supplies list was sufficient for my lighting patterns but it's insufficient for lighting all the pixels in white at full brightness.
2. The 1000 microfarad capacitor should be connected across the positive and ground wires to the LED panel to handle sudden increases in demand from the LED panel
3. The 330 ohm resistor should be connected between the Data pin from the MCU and the Data wire going into the LED panel to prevent any startup voltage spikes from damaging the first pixel on the LED panel.

1. Here is the code that I used. It has calming/dreamy lighting patterns: https://gist.github.com/adkeswani/d2b37f52d45ebd3448b8ab400bc5b46c
2. If POWER_WALL is #define'd the LEDs will use full brightness and the max current is set to 2.5A. The FastLED library will automatically scale down the brightness if the current is going to exceed this amount.
3. While testing and tweaking patterns, it's useful to power the MCU and panel using USB, so when POWER_WALL is not #define'd the brightness and max current are restricted so as not to exceed the USB port's capacity.