GridDown Secure Messenger

Unsupported Browser

This flasher requires the Web Serial API, which is only available in Google Chrome or Microsoft Edge on desktop. Safari, Firefox, and mobile browsers are not supported.

Connect Device

Disconnected

Plug your T-Deck CYPHER M8K into your computer via USB-C. The device uses the ESP32-S3's built-in USB — no external driver needed.

If the device is not detected:

Hold the BOOT button on the T-Deck
While holding BOOT, briefly press and release RESET
Release BOOT — the device is now in download mode
Click "Connect Device" below

The device appears as "USB JTAG/serial debug unit" or similar Espressif device in the browser dialog.

Select Firmware

Choose the firmware version to install. Stable releases are recommended.

Full erase before flashing (recommended for clean installs)

Full erase removes all data: saved configuration, LittleFS filesystem, and NVS settings. Uncheck to preserve device settings during a firmware update.

Merged binary includes bootloader (0x0), partition table (0x8000), OTA selector (0xE000), and application (0x10000). Flash mode: DIO (bootloader switches to QIO at runtime). Flash size: 16MB.

Flash Firmware

Do not disconnect the USB cable or close this tab during flashing.

Console Output

GridDown Secure Messenger Flasher v1.1

Target: T-Deck CYPHER M8K (ESP32-S3FN16R8, 16MB flash, QIO/OPI)

Flash config: mode=dio, freq=80m, size=16MB, offset=0x0

Waiting for device connection...