This Daylight-Readable Twin-Show PDA Acts as Its Personal Software program Improvement Device

Pseudonymous maker “jefmer” has taken a compact keyboard equipment and turned it into a private digital assistant (PDA) — including standalone smarts and a pair of sunlight-readable reflective shows, proving its capabilities by writing the gadget’s software program on the gadget itself.

“I get pleasure from programming and get pissed off that tablets and laptops will not be actually usable in direct daylight,” jefmer writes of the inspiration behind the challenge, which takes as its inspiration pocket-friendly PDAs from the ’80s and ’90s. “The Pocket Pad prototype is my try to provide a small PDA like gadget that I can use within the nice outside. To this finish, I’ve mixed a PocketType miniature 40% keyboard with two very low energy [Sitronix] ST7302 monochrome shows and a Good!Nano nRF52840 based mostly controller board.”

The keyboard is an off-the-shelf equipment, designed to place an ortholinear format in a particularly small area. Usually, a footprint on the bottom-left of the keyboard performs host to an Arduino Professional Micro-compatible microcontroller board that acts because the keyboard’s controller — however within the Pocket Pad’s case, this has been swapped out for a Good!Nano with a extra highly effective Nordic nRF52840.

Above the keyboard, jefmer has added a pair of compact 2.13″ 250×122 monochrome Sitronix ST7302 shows. “This show is much like a Sharp Reminiscence Show in that has no backlight and it permits a lot quicker updates than ePaper shows,” the maker explains. “In low energy mode with body refresh set to 4Hz, every show makes use of on common 30 microamps. It’s [also] versatile, in that, in excessive energy mode it might probably replace at a 32Hz body price with present consumption nonetheless lower than 1 milliamp.”

The software program for the PDA is written in Gordon Williams’ Espruino, a JavaScript port constructed for embedded microcontrollers. Whereas the show and keyboard drivers had been developed off-device, together with a textual content editor, the remainder of the gadget’s software program was developed on the Pocket Pad itself in a powerful feat of bootstrapping.

“The editor can open and edit all the JavaScript recordsdata saved on the gadget,” jefmer explains. “After all, which means it’s potential to trigger a crash that may solely be repaired utilizing the WebIDE, nonetheless, it additionally means the gadget can be utilized to improve itself and repair issues on the fly. The editor makes use of the arrow keys to navigate and choose textual content, and helps the same old copy, lower and paste operations.”

Along with the editor, jefmer has written a clock utility, Bluetooth help for notifications from related Android or iPhone gadgets, and an app that permits it to behave as a Bluetooth keyboard for different computer systems. “For a future model,” the maker muses, “I can not resolve between a clamshell on the strains of a Psion PDA or a pill format which might be extra sturdy as hinge-less.”

The challenge is documented in full on jefmer’s Hackaday.io web page; the supply code is offered on GitHub beneath an unspecified license, together with the maker’s different Espruino initiatives.