Flash, update, and recover

Supported target: official M5Stack StackChan K151, ESP32-S3, 16 MB flash, 8 MB Quad PSRAM. Other CoreS3 boards and DIY Stack-chan builds need a different hardware port.

Browser installer

Open Dash-Chan Web Flasher in desktop Chrome or Edge on HTTPS. Firefox/Safari and phone flashing are not supported by this interface.

1. Connect a USB data cable. Close PlatformIO monitors, other browser serial sessions, and desktop serial tools. Stop any wardrive.
2. Confirm the official K151 checkbox and click Connect StackChan. Choose its Espressif USB serial port. The flasher validates ESP32-S3 and 16 MB; these checks cannot distinguish a K151 from another board with the same chip.
3. If this is your first installation, use Download factory backup. It reads all 16 MB and downloads a SHA-256 companion file. Keep both private. Backups may contain original settings and credentials.
4. Click Install Dash-Chan. Downloads are checked against SHA-256 before any flash write. Four split images are written without whole-chip erase. Each written image is verified with the chip's MD5 operation.
5. The installer reads the NVS/calibration range before and after writing and checks that it is unchanged, then explicitly pulses reset. Look for the BWM/VTS boot screen and your pet. Disconnect closes the browser's serial handle.

The site self-hosts a pinned esptool-js bundle and all firmware files. There is no runtime CDN, analytics, external font, or server-side serial connection. Firmware downloads need internet; the robot runs offline afterward. The microSD is never formatted by the installer.

If port selection is canceled, reconnect normally. During writing, keep USB connected and the tab open. If a write/check/reset fails, the page reports the failure; it never labels an unchecked image successful. Re-enter boot mode and retry the same release. A post-flash automatic browser-side application handshake is not performed; the displayed success means flash checks and calibration preservation passed, not that GPS or every peripheral is working.

Boot mode and connection trouble

• On K151, hold the bottom RST button beside the microSD slot for about three seconds, then release when its indicator turns green. Select the newly appearing Espressif port. This is the official M5Stack download-mode procedure.
• Try another data cable or direct computer USB port. A power-only cable will not work.
• Close all other users of the serial port, including the avatar uploader. Installer and avatar upload cannot own it simultaneously.
• If the installer completed but the face has not appeared, briefly press RESET.
• Do not use “erase flash” as a connection fix. It destroys NVS and can remove factory servo calibration.
• GPS WAIT does not mean installation failed. Confirm blue Port C, the selected baud, and a clear sky view.

Manual flashing

Download the release ZIP from Releases, extract it, and verify SHA256SUMS.txt before writing.

python -m pip install esptool==5.4.0
python -m esptool --chip esp32s3 --port YOUR_PORT read-flash 0x0 0x1000000 stackchan-factory.bin
python -m esptool --chip esp32s3 --port YOUR_PORT --baud 460800 write-flash --flash-mode dio --flash-freq 80m --flash-size 16MB 0x0 bootloader.bin 0x8000 partitions.bin 0xe000 boot_app0.bin 0x10000 firmware.bin

Replace YOUR_PORT with the confirmed robot port (for example COM60 on the development machine; do not assume that number on yours). DIO in the boot header is required on the tested K151 configuration. The Arduino qio_qspi memory profile is a separate PSRAM/build setting and should remain as pinned.

The package and browser both validate sector-rounded image bounds. An app-only update at 0x10000 is appropriate only after this Dash-Chan partition layout is already installed. A first installation needs all four split images.

Restore the original firmware

Use your own complete 16 MB backup for this specific robot. Check its saved SHA-256 first. Restoring overwrites the firmware and settings with the backed-up state; it does not change SD files.

python -m esptool --chip esp32s3 --port YOUR_PORT --baud 460800 write-flash 0x0 stackchan-factory.bin

Do not substitute another robot's backup or calibration. If your original backup is missing, consult M5Stack's official recovery/calibration documentation for the exact model.

Build the same release

git clone https://github.com/valleytechsolutions/Dash-Chan.git
cd Dash-Chan
git checkout v0.5.0-beta
python -m pip install platformio==6.2.0
pio run -e stackchan
python tools/package.py

The ZIP contains split images, install instructions, corresponding-source links, checksums, and runtime license notices. The package script also prepares site/firmware/ for the static web flasher.