Penkesu Computer - A Homebrew Retro-style Handheld PC

View the Project on GitHub penk/penkesu

Penkesu Computer - A Homebrew Retro-style Handheld PC

Penkēsu (Japanese: ペンケース) is a retro-style handheld device powered by a Raspberry Pi Zero 2 W, a 7.9 inch widescreen display (1280 x 400 resolution), and a 48-key ortholinear mechanical keyboard.

The Design

The enclosure of Penkesu Computer is designed around the display and keyboard to achieve a (relatively) compact physical dimensions.

Repurposed Gameboy Advance SP hinges and ribbon cable for HDMI are used to keep the hinge design thin, yet they hold the weight of the display so it won’t tip over.

Electronics are kept to be minimal (3 internal components) and most of the parts are either 3D printable or off-the-shelf product.

See also: the keyboard sound test video.

Open Source Hardware

Ever since the CutiePi tablet has been successfully funded and started shipping, I feel the need to work on a new project, something I don’t need to worry too much about commercial viability, and to remind myself why I started tinkering. A “rebound” project, so to speak.

And since there are no immediate plans on selling kits or making Penkesu Computer mass producible, I’d like to publish all the designs and plans so there’s enough information for anyone interested in making one.

Bill of Materials

Links are not affiliate links, and only provided as references.

Notes on the Keyboard

About the keyboard:

For the keycaps:

The Assembly

  1. Glue two hinges to the chassis (my 3D printer is not accurate enough to print a fully functional hinge lock, so I simply glued them with 5 minute epoxy)

  1. Add heat-set threaded inserts (M2x6) to the 4 corners of screen bezel, and 2 to the hinge cover

  2. Wrap the ribbon cable twice and pull it out through the hinge cover

  1. Wiring:

    Component Pin
    battery positive PowerBoost Bat pin
    battery negative PowerBoost GND pin
    switch 1 pin PowerBoost GND pin
    switch 2 pin PowerBoost EN pin
    PowerBoost 5V OUT display and Pi Zero’s VCC
    PowerBoost GND display and Pi Zero’s GND

  2. Connect keyboard’s micro USB and display’s mini HDMI port to Pi Zero 2 W; inset micro SD card into Pi Zero 2 W
  3. Fasten all components with M2x6 screws

If you made it this far, welcome to check out my other project, the CutiePi tablet, which is also a 100% open source hardware! :-)

Copyright (c) 2022 Penk Chen. All rights reserved.

All files are licensed under MIT license, see the LICENSE for more information.