Software program engineer and maker Bob Sheldon III has taken the outdated problem of “can it run Doom” to an uncommon place: operating it not on a keyboard’s controller itself, however totally contained inside a keycap on mentioned keyboard — due to a hidden Raspberry Pi RP2040 microcontroller.
“Primarily based on an RP2040 [microcontroller], my customized PCB runs a modified model of the Raspberry Pi Basis’s Doom port,” Sheldon explains of the mission, which shrinks Id Software program’s seminal 1993 first-person shooter all the way down to the footprint of the backspace key on a keyboard. “What’s extra, the code is open supply!”
Sheldon’s self-contained computing keycap makes use of a customized PCB which performs host to the Raspberry Pi RP2040, a dual-core Arm Cortex-M0+ microcontroller which runs at 133MHz — however which has solely 264kB of RAM, which proved probably the most difficult a part of porting Doom to the machine when Graham Sanderson first managed it again in March final yr.
This tradition PCB is paired with a small-form-factor OLED show panel, handily barely smaller than the footprint of a keyboard’s backspace key — and which is then encased in a 3D-printed keycap shell to guard it and permit it to nonetheless stay practical as a keyboard key.
The mission is notably much like the work of James Brown, who additionally took Sanderson’s Doom port and encased a Raspberry Pi RP2040 in a protecting enclosure — however relatively than constructing a keycap, Brown constructed a fully-functional LEGO laptop brick, full with motion-based and capacitive controls to permit the sport to run totally independently.
A 3D-printed keycap shell holds the show plus a customized RP2040-based PCB, with a USB OTG port for an exterior keyboard. (📷: Bob Sheldon III)
Sheldon has indicated plans to commercialize the Doom-running keycap design, which requires a keyboard and mouse to be related through a USB To Go (OTG) adapter if you wish to do extra than simply watch the demo, although says there’s “slightly R&D to do” on the mission but earlier than it is able to launch — and, up to now, no pricing has been disclosed.
Sheldon’s modified supply code is offered on GitHub underneath the reciprocal GNU Normal Public License 2, with added compatibility for chosen SPI and I2C shows; he has not launched design recordsdata or schematics for the customized keycap-sized PCB.
