Flashing the firmware

firmware
getting-started

This guide documents how to transform an assembled board to a running Critter Scanner. There are two ways to flash the firmware.

Things needed

An assembled Critter Scanner board (ESP32-S3)
A USB-C data cable — a charge-only cable is the single most common cause of “it won’t connect”
Either a Chromium browser (for web flashing) or PlatformIO (for the command line)

Option A — Flash in your browser (easiest)

Head to the flasher, plug the board in, and follow the prompts. It works in Chrome, Edge, and Opera on desktop. Nothing to install.

If the button says the installed browser isn’t supported, use Option B — Safari and Firefox don’t support Web Serial yet.

Option B — Flash from the command line

Clone the firmware and flash via PlatformIO:

git clone https://git.gaycats.fyi/amxy/TranymonFirmware
cd TranymonFirmware
pio run -e esp32dev -t upload   # build + flash over USB
pio device monitor              # serial console @ 115200

Entering download mode

Most boards reset into the bootloader automatically. If the upload doesn’t start:

Press and hold the button on the back labeled BOOT.
Connect the USB cable.
Firmly press Reset once, while still holding BOOT.
After flashing is done, release BOOT and firmly press Reset.

In case of “Unable to verify flash chip connection / serial noise or corruption”, the board did enter download mode, but the serial link is noisy — swap to a known-good data cable and a direct USB port (skip hubs), then retry.

Verifying a downloaded image

Verify images before flashing:

sha256sum -c critterscan-v{VERSION}.bin.sha256

In case of critterscan-v{VERSION}.bin: OK everything is correct. On Windows PowerShell, compare Get-FileHash critterscan-v{VERSION}.bin -Algorithm SHA256 against the hash on the firmware page.

Confirm it worked

Reconnect and open the serial monitor at 115200 baud; the firmware prints its version on boot. If it matches what you flashed, you’re done.

Signed releases are coming: once GPG signing is in place, each image will also carry a detached .asc signature to verify against the project key.