Still in development, so specs and features presented here are not final!
USB-C Amp-Meter V3
After scrapping V2, I took a step back and started fresh. Here's what's different:
V3 PCB, back rendering
V3 PCB, front rendering
- proven RF design: back to using a premade ESP development module — no more hand-rolled antenna lines on a two-layer PCB. This gives reliable Wi-Fi out of the box, making OSD communication over Wi-Fi and over-the-air firmware updates possible, all while keeping the BOM cheaper than the ESP32-C3 + discrete antenna approach.
- direction-agnostic USB-C: instead of blindly routing USB data and CC lines 1:1, the new design determines plug direction and switches the lines in hardware on both ports. Plug direction finally doesn't matter anymore — just plug in and go.
- colour display via SPI: a slightly bigger colour display, now connected through SPI. This frees up I²C entirely for voltage and current measurements, enabling even higher measurement rates.
- remote power switching (planned for 3.1): a MOSFET switch to turn the device under test on or off remotely, so you don't have to physically unplug and replug to diagnose startup behaviour. The OSD software will then be enhanced to automatically diagnose faults based on the current-draw signature.
PCBs are ordered and should arrive in July 2026. Testing can start as soon as they land.
As always, this is a research project first and a product second. I'll update this page once I have hardware in hand and real numbers to share.