Non-engineer builds a modern HP Jornada palmtop with GPT-6 Astra doing the engineering reasoning
Wuliyasi · reddit · 2026-09-08
A Reddit user with no electrical or mechanical engineering background shares how GPT-6 Astra + Codex carried a real hardware project: a modern reinterpretation of the late-90s HP Jornada palmtop.
The build: an original Jornada 688 keyboard, a removable BOOX P6 E-Ink device, a custom nRF52840-based controller, BLE HID, USB-C for charging/firmware/debugging, plus a completely new enclosure, hinge and internal mechanical architecture.
The workflow: the author defines goals, disassembles, measures, solders and prints prototypes, while Astra does most of the engineering reasoning — reverse-engineering the keyboard matrix, FFC analysis, HID design, MCU selection, PCB planning, battery/charging architecture, hinge load paths and packaging. The loop: describe goal → Astra identifies unknowns → designs an experiment → author performs the physical test → Astra interprets results → Codex updates the design → repeat.
Concrete example: after removing the 25-year-old Jornada 688 keyboard, the author used Astra to reason through the FFC, build a safe probing methodology, and gradually map the unknown matrix for use with a modern wireless controller.
The project leans heavily on open source, including Un Kyu Lee's Micro Journal / phone-enclosure and several Thingiverse Jornada palmtop projects (5590156, 6938611, 6966529).
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