Casio F-91W RLCD

Waveshare ESP32-S3 4.2″ reflective LCD · MikeDX / casiof91w-rlcd

Flash firmware

Install the latest build in Chrome or Edge (desktop). Connect the board via USB.

Use Chrome or Edge on a computer (Web Serial required). Open this page via HTTPS (e.g. GitHub Pages).

Firmware version: …

After flashing

  1. Board reboots and shows SET on the LCD.
  2. Join Wi‑Fi F91W-Setup on your phone.
  3. Complete the captive portal (home Wi‑Fi, NTP, timezone).
  4. Watch syncs time and runs normally.

Factory reset: hold BOOT + KEY for 3 seconds after boot. Timezone help: posix.carla.spiers.fr

Hardware