The Pixel Panel is a 25x25 custom NeoPixel matrix that utilizes an ESP32 as the brains of the operation running WLED software. The matrix can be remotely changed using the WLED app with preset patterns and colors or, the user can create custom designs of their own. The case covering the PCB is created from ABS sheets that were created using makercase.com and fabricated using a laser -cutter.

Below are some final shots of the BK2 Camping Knife from different angles to highlight individual design aspects.

The process began by designing the ABS case using makercase.com before saving the .dxf files and sending the to the laser cutter. After each piece was cut out, a little post processing was needed to remove the plastic film off the ABS and slight burns marks on the plastic were removed using isopropyl alcohol and a rag.

After this, the PCBs were assembled by first using a screen to apply solder paste to the contact pads for the NeoPixels. Each board was then individually loaded into a pick-and-place machine to apply the NeoPixels. The boards were then placed two at a time into a reflow oven to melt the solder paste and secure the components. 

One board was then selected to have the ESP32 and other components surface mount soldered to the backside. This was accomplished by again using a screen to apply solder paste and then hand placing the various components before placing the PCB NeoPixel side down on a silicon mat before leaving it in the reflow oven for around 5 minutes. This ensured the NeoPixels would remain in place and undamaged by heat from the oven rack. The finished boards were then connected together to form a singular matrix. Certain contacts had to be bridged with solder while others were covered with kapton tape.

Once the board was fully assembled, the Arduino IDE was used to upload a test sketch in order to make sure the ESP32 could work with a boot-loader. The WLED software was then uploaded to the ESP32 over the usb connection from the WLED website. The app was used to configure the NeoPixel matrix layout and to upload patterns.

After this, the frame was assembled using the laser-cut ABS however, the pieces warped badly as they were left sitting and the frame became unusable to achieve the desired effect. The white ABS cover was still usable though so it was incorporated into the following design.

Fusion 360 was used to recreate the grid as a singular piece with offsets for the threaded inserts that would be used to anchor the PCB to the plastic frame. The dimensions were 200 mm x 200 mm, with individual cutouts measuring 18.35mm x 18.35 mm, and a wall thickness of 1.5 mm alongside a height of 20 mm. A lip was also added to help secure the ABS screen to the PLA base. An Ender S1 was used to print both pieces.

Once each piece was printed, they were assembled using CA glue. Acrylic inserts were laser cut to hold heat set inserts that are used to mount the PCB to the grid. Once the grid was finished, the diffuser was layer overtop and the lip was slid over the entire assembly.