Maker Jay Doscher has built a ruggedized miniature all-in-one computer from a Raspberry Pi — complete with integrated battery pack, network switch, and electromagnetic shielding in case of nuclear attack: the Raspberry Pi Recovery Kit, an "off-grid cyberdeck."
Doscher's experiments with a portable, low-cost, ruggedised all-in-one started in 2014 with the development of a Raspberry Pi Field Unit. The build brought up some criticism, however: it had no keyboard, holes in the plastic chassis meant it wasn't waterproof, maintenance was a challenge, and the material choices meant an increased likelihood of breakage. The 2019 variant, in contrast, fixes all these issues — and in doing so creates something even more impressive.
"In 2014 I wasn’t aware of any reduced footprint keyboards, and I did look. Even looking today there wasn’t any that fit common search terms, but as a lurker in /r/mechanicalkeyboards I did find out and had already bought a Plaid keyboard kit," Doscher says of the new unit's keyboard. "As luck turns out, it was a perfect fit.
"To state it up front, I did not intend to make something fully submersible for long periods. This is a hobby project and in order to do that, you end up using high-end adhesives. No thanks. Instead, I chose to move all the components and connectors inside the Pelican case. While not all Pelican cases seem to be rated to be waterproof, I’m at least not drilling any holes into this one.
"My wiring abilities from several years ago were pretty poor — notably I just randomly selected lengths of wire and shoved in what didn’t fit. Two simple rules seem to have helped me wire this project better. First, use only the length of wire needed, but make sure there’s slack to do connecting and soldering, and make sure wires are equal length when connecting to the same part. All of those more or less go together, but help reduce the amount of clutter. Second, I try to zip tie cables that route together. Zip ties can be the enemy, but in small confined spaces they’re very important. By grouping cables logically, it’s easier to trace cables when troubleshooting."
The finished build integrates a Raspberry Pi 3 Model B+ with LCD screen, five-port Ethernet switch, and a battery pack, along with rugged connectors for the GPIO port's pins. In a nod to the "preppers," the redesign also includes electromagnetic shielding — but in the cardboard box used for storage and transportation rather than the Pelican case itself, in order to avoid blocking the Raspberry Pi's Bluetooth and Wi-Fi radio.
"There are some cool plans I have for the Raspberry Pi Recovery Kit," Doscher explains. "Automate mirroring of Raspberry Pi images; create a repository for apt packages for Raspbian in case of an extended internet outage; script the periodic downloads of Linux install images. This was a fun project to work on, and I hope someone remixes it and comes up with their own."
Doscher's website has a more detailed write-up with bill of materials, along with links to the 3D print files published under a Creative Commons Non-Commercial licence.