Pseudonymous creator Pubudeux has published a build log for a project to convert low-cost 20" LCD monitor into an all-in-one PC for a kid with a very clear color scheme in mind, powered by a Raspberry Pi 4 Model B 4GB single-board computer (SBC).
"So it all began with a forceful statement: 'I want a purple unicorn computer,'" Pubudeux explains of the project's origins. "Hearing that request got me really excited about figuring out a way to make it happen and make a kid very happy. I decided to build a low-cost, low-power all-in-one computer powered by a Raspberry Pi that would be easy to use and fulfil the original requirements of my customer."
The project began simply enough with the disassembly of an off-the-shelf low-cost 20" display, which was then spray-painted with a purple gloss. "Just remember that this is in no way returnable after doing this," Pubudeux warns. "You WILL damage the outer casing of the monitor by doing this."
With the paint finished it was time to turn the monitor from a dumb display into a fully-functional all-in-one computer. "I went into it not sure if I'd actually be able to fit the Raspberry Pi inside the empty space in the monitor," Pubudeux admits, "and was pleasantly surprised to find out that it all worked out fairly well."
The Raspberry Pi 4 Model B was paired with a 256GB microSD card for OS and storage, while a DC-DC buck converter provides its power from the display's own power circuit. The project also required cabling to connect the monitor's HDMI input to an HDMI output on the Raspberry Pi, with Pubudeux opting for a flat ribbon cable: "Be aware," they warn, "it must be insulated as this is unshielded. Without insulating this, the Wi-Fi signal severely interferes with the HDMI signal and makes the computer unusable. I addressed this with regular electrical tape and it worked great."