SynDimm: a wall dimmer that stays in sync with the smart home

A classic rotary dimmer on the wall and a smart home app know nothing about each other: turn the knob and the app shows the wrong state, switch from the app and the knob is wrong. SynDimm resolves the conflict with an ESP32-C6 behind the encoder: every turn is reported at once to Shelly, Philips Wiz or Home Assistant, and every change from there is mirrored on the device.

Three modes on the same knob

• Dimmer. 0 to 100 %, smooth transitions, preset start brightness, RGB colour, scenes and groups. State synced instantly in both directions.
• Shutter. Percentage position for blinds, calibration, limits, favourite position.
• Safe. The encoder becomes a lock: five turn sequences as passwords, each triggering its own HTTP call (GET, POST, PUT, DELETE, with bearer or basic auth, custom headers and JSON body). Open a gate, start a scene or notify a server without any app.

Build

Two firmware layers: HW (ESP-IDF, drivers, web server, OTA with rollback protection) and GUI (web interface, multilingual, updated separately over OTA). The board is drawn in KiCad. A build script keeps all artefacts outside the source folder.

Open

Safe profiles, MQTT broker and a device card exist in hardware but not yet in the interface. Roadmap: concept, dual power and multi-mode reached; next stable Shelly and Wiz integration, then the announcement.