Karliss' Sinclair-Like Vinyl-Cut Steam Deck Keyboard Serves As an Experiment in Flexi-PCB Prototypes

Pseudonymous gamer and keyboard enthusiast "Karliss" has designed an unusual accessory for Valve's portable Steam Deck console: a "paper-thin" keyboard, designed to squeeze into the official case and powered by a Raspberry Pi Pico microcontroller.

"[It's a] paper-thin keyboard that fits in the original case for [the] Steam Deck," Karliss explains of the project. "When closed the part with microcontroller board should fold and fit into the recessed part of case without applying pressure to screen. [It's] not practical in any way, mostly an experiment for making flexible PCBs using [a] vinyl cutter."

Valve's Steam Deck launched in February last year, taking what the company had learned from its Steam Controller hardware and Linux-based Steam Machines PCs-cum-consoles and mashing them together to create a handheld machine which can play mainstream PC games from the company's Steam platform on-the-go. While it boasts clever touchpads, joysticks, and a touchscreen display, though, it lacks a keyboard for text entry — which is where Karliss' design comes in.

While functional, though, the keyboard really serves as a test bed platform for the rapid prototyping of flexible PCB designs using a vinyl cutter and low-cost materials: transparency film, designed for overhead projectors, and copper tape, arranged in a film-tape-film-tape-film sandwich finished with labels for each key.

"In theory the glue of copper tape was supposed to be somewhat conductive. With bigger overlapping patches it somewhat worked," Karliss writes, "but with thinner traces it was somewhat unreliable. [I] had to add small dots of soldering to connect the strips of copper tape together more reliably. Making PCBs using copper tape and vinyl cutter […] almost works but [is] not very practical. [The] final result was more robust than I expected ([but] still fragile)."

And the keyboard itself? "[The] typing experience was awful (which was somewhat expected from [a] flat sheet with no tactile feedback)," Karliss admits — a feeling which would be familiar to readers of a certain age who "enjoyed" the membrane keyboards fitted to the Sinclair ZX80 and ZX81 microcomputers in the 1980s. "[I] was able to get ~10 WPM [Words Per Minute] on [the] Monkeytype page."

The full project write-up, along with the design files and instructions for trying it yourself, is available on Karliss' Hackaday.io page.