Web Serial API proof-of-concept. Chromium / Chrome / Edge only — not Firefox.
Must be served from https:// or http://localhost
(open via file:// won't work).
For a quick local test: run python3 -m http.server 8000 in this
folder, then open http://localhost:8000/gedge_serial.html.
F#####I##D######: F=Hz (00000–99999),
I=intensity (00–20), D=duration ms (000000–999999).