Undermount AC

ESP32-S3 controller beta installer

Controller firmware · latest beta

Flash the beta controller firmware.

Use this page to install the current Undermount AC controller beta onto an ESP32-S3 controller board. This is for the controller firmware only, not the remote display firmware.

Install firmware Connect the controller board by USB, then click Install. Use Chrome or Edge on desktop.
Before flashing: disconnect vehicle loads where practical, keep the controller powered from a stable USB source, and do not unplug during flashing. Flashing will replace the current firmware on the ESP32-S3 controller.

1. Prepare

  1. Use a data-capable USB cable.
  2. Open this page over HTTPS or localhost.
  3. Close Arduino IDE serial monitor or any other program using the port.

2. Flash

  1. Click Install.
  2. Select the ESP32-S3 serial port.
  3. Wait until the installer reports success.

3. Verify

After reboot, the controller should broadcast its local setup network and expose the controller web UI/API once running.

Firmware target

ESP32-S3
Undermount AC controller
latest beta

Included controls

Web UI, AP/STA networking, MQTT/Home Assistant support, °F/°C selection, and controller API endpoints.

Support note

For beta testers, record the board serial/port, firmware version, and what happened before reporting an issue.

Maintainer note: place the newest merged controller binary at firmware/latest.bin. The manifest always points to that fixed file name, so the installer page does not need to be edited for each firmware version.