EEVblog has moved its 121GW multimeter firmware experiment from generated code to a bench test. In a 39-minute video published on 3 November 2026, Dave Jones shows a C-language reverse-engineering effort using Claude Code, then programs and tests the resulting firmware on a physical 121GW.
The demonstration is the important step beyond his earlier attempt: a program that looks plausible in a disassembler is not the same as one that runs on the instrument. The video walks through the bootloader and firmware work, the programming process, a live meter test, and a Bluetooth check. EEVblog has also published the reverse-engineering project for inspection.
This is a striking hardware-repair and preservation case study, but one successful bench demonstration is not a full validation of every measurement mode or safety behavior. The value for makers is the visible chain from firmware analysis to an actual device, with code available to examine.
Watch the original: EEVblog 1784 — Claude Code Reverse Engineer 121GW Firmware SUCCESS!
