SixBack

SixBack — Web Flasher

Local SoundTouch cloud replacement on an ESP32 stick.
Bose shut their cloud down — this brings the preset buttons back.

Source code & bug reports: github.com/tostmann/SixBack

Install SixBack on your ESP32

Plug your ESP32 board into USB, click below, and pick the serial port that appears.
The browser detects the chip and flashes the matching image.


Fresh install — erases all settings
Update existing — keeps WiFi + presets + Spotify auth

Version … — pick Fresh install for a new stick, Update existing for a stick that already runs SixBack.

ESP32-S3-DevKitC-1 has two USB sockets — since v0.8.35 you can use either one. The socket labelled UART appears as a CH340/CH343 serial port and also carries the console log. The board's native USB socket now works for the complete run as well — factory flash and the “Connect device to Wi-Fi” step have been verified end-to-end over it, because this image answers the provisioning handshake on both ports. Releases before v0.8.35 answered on the UART port only.

Two harmless things you may notice in the browser's developer console: an “Error fetching current state: TIMEOUT” appears at roughly 88 % of the flash — that is the tool's provisioning check timing out while the chip is still in download mode, the flash continues and completes normally. And on the native USB socket the console log shares the port with the handshake, so in rare cases the browser may report “Improv Wi-Fi Serial not detected”; if that happens, or if a run stops at Hard resetting via RTS pin, just retry, use the UART socket, or set up Wi-Fi through the SixBack-… hotspot the stick opens. Single-socket boards (XIAO S3, ESP32-C3 / C6 / C5) have only one port and are flashed and provisioned over it as usual.

ESP32-S3 with 8 MB flash (Seeed XIAO ESP32S3 & similar)

The buttons above flash the 16 MB S3 layout. Boards with only 8 MB flash + PSRAM (e.g. Seeed XIAO ESP32S3) need this dedicated image instead — the standard one does not fit and the flash would fail partway through.


Fresh install (S3 8 MB) — erases all settings
Update existing (S3 8 MB) — keeps settings

Not sure which one you have? The Nxx in the module name tells the flash size: N8… = 8 MB, N16… = 16 MB. XIAO ESP32S3 / Sense = 8 MB; XIAO ESP32S3 Plus = 16 MB (use the standard buttons above). PSRAM is required either way.
Use the update button only for the variant the device was originally flashed with — a device running the 16 MB layout must use the standard update button, and vice versa. Already-flashed devices show their layout in the Web UI status line ("ESP32-S3 8MB" / "16MB").
Manual flashing (esptool): factory @0x0 · firmware @0x10000 · littlefs @0x610000

⚠ Auto-migration runs by default. Right after WiFi provisioning, SixBack will automatically discover every SoundTouch speaker on your LAN (model whitelist SoundTouch 10/20/30, firmware 27.0.6.x / 27.0.3.x) and rewrite its cloud URLs to point at the stick — each speaker reboots once in the process (~60 s). Existing presets are preserved automatically. After the initial boot pass the auto-mode stays armed as a periodic cron (default every 30 minutes) and picks up newcomers automatically.

If you want to drive migrations by hand, open http://sixback.local/ right after provisioning and flip the Auto-Migrate at Boot switch at the top before the device finishes discovering your speakers.
Recommended hardware: ESP32-S3-DevKitC-1-N16R8 — 16 MB flash, 8 MB PSRAM, mature WiFi 5 stack. In extended end-to-end testing this was the most robust target. ESP32 / C3 / C6 / C5 work too (factory image auto-selected), but the C6's WiFi 6 stack occasionally needed a second boot to discover all speakers, and the 4-MB targets are tight on flash for future features.

Only the ESP32-C5 speaks dual-band 2.4 / 5 GHz WiFi 6 — pick it if your network runs on 5 GHz. Every other target is 2.4 GHz only (the C6 is WiFi 6 but 2.4 GHz only). The C5 image is auto-selected by chip family just like the rest.
Browser requirement: Web Serial is only implemented in Chromium-based desktop browsers — Chrome, Edge, Opera, Brave on macOS / Windows / Linux. Safari, Firefox and all mobile browsers are not supported.

What you get

After flashing, point your browser at http://sixback.local/: discover the speakers on your LAN, migrate them off the dead Bose cloud, and manage all six preset buttons by drag & drop — search TuneIn / add custom streams in the sidebar, drag tiles onto preset slots, push to the speaker.

SixBack Web UI — TuneIn search sidebar + per-speaker preset slots
SixBack Web UI — TuneIn search on the left, per-speaker preset slots on the right, drag & drop to assign.

Supported targets

…

How it works

  1. Click CONNECT above and pick the serial port of your ESP32.
  2. esp-web-tools reads the chip family from the bootloader and selects the matching factory image from manifest.json.
  3. The factory image — bootloader + partition table + firmware + Web UI — is written to 0x0 in one shot. Old contents are erased.
  4. After reboot, SixBack starts in Improv-Wi-Fi mode and waits for credentials. esp-web-tools offers the Improv flow right after flashing, so you can hand over Wi-Fi SSID and password from the same page.
  5. The device then advertises itself as sixback.local on mDNS; open http://sixback.local/ to manage your Bose speakers.
OTA updates later: once SixBack runs on the device, future updates can be uploaded via the Web UI's System panel without USB — that's what the *-firmware.bin and *-littlefs.bin files next to the factory images are for.

Manual install (if Web Serial doesn't work)

Each target ships three artefacts you can download and flash manually with esptool.py:

Example:

esptool.py --chip esp32s3 -p /dev/ttyACM0 write_flash 0x0 sixback-s3-factory.bin
License — Noncommercial Use Only. By clicking INSTALL above you agree that you will use this firmware for personal, hobby, research, or other noncommercial purposes only. Selling devices with this firmware pre-flashed, offering it as a paid service, or any other commercial use requires a separate written license from the copyright holder. Full terms: PolyForm Noncommercial 1.0.0 · commercial inquiries: tostmann@gmail.com.