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Flash Nimbus from the browser

Install the latest Nimbus firmware release on an ESP32-S3-DevKitC-1 board straight from this page - no toolchain, no downloads. The full walkthrough (including the command-line path) is in Quick Start → Flash the firmware.

You need
  • Chrome or Edge on a computer - the flasher uses Web Serial, which other browsers and phones don't support.
  • A data-capable USB cable - many USB cables are charge-only and never show a serial port.
Nimbus board: use the port labeled UART. The DevKitC-1 has two USB-C ports and only one can flash a fresh board. Plug into the port silkscreened UART, not USB - on a factory-fresh board the native USB port has no path into download mode until Nimbus owns it. A board that "won't flash" on that port is not broken; it is on the wrong port.

The image is matched to your board and screen size, so it comes up on the right display and already knows which updates it should get.

This browser can't flash devices - use Chrome or Edge on a computer.Flashing needs a secure (HTTPS) page - reload this page over HTTPS.

Pick the board's serial port when the browser asks. Choosing "Erase device" is fine on a new board; on a board already running Nimbus it wipes its saved settings.

After flashing

  • Ignore the flasher's Wi-Fi prompts. If the dialog offers to connect the device to Wi-Fi after installing, skip/close it - Nimbus provisions itself through its own setup network, not through the flasher.
  • On your phone or computer, join the Wi-Fi network named Nimbus-setup (the password is shown on the device screen, unique to your device - or just scan the on-screen QR to join) and the setup wizard opens in your browser. Step-by-step: Set up the device.
  • The screen is ready right away. The image you picked already tells the board which display it has, so it comes up on the correct panel - there is no blank-screen step and no display question in the wizard.

If no serial port shows up

  • Swap in a known-good data cable (the most common cause).
  • Confirm the cable is in the UART port and try another USB port on the computer.
  • Recovery and port details: Flash the firmware.

Verifying the image (optional)

First-time flashing writes the image as-is - like any firmware installer before secure boot, it is not signed. If you want to confirm the bytes before flashing, the image's SHA-256 is published next to it at raw.githubusercontent.com/ristllin/nimbus-fw-releases/webflash/latest/nimbus-webflash.bin.sha256. Over-the-air updates after setup are ECDSA-signed and verified on the device.