techo5

README

Your Echo Show 5, rebuilt. Linux inside, Home Assistant in charge, no Amazon cloud.

Why · Screenshots · Stock vs TECHO5 · Install · Under the hood · Credits · TECHO5 Dot

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TECHO5 (Tech Echo 5) is open firmware for the Amazon Echo Show 5, 2nd generation (2021, cronos). It replaces Android and Alexa with a small Alpine Linux image and one Go daemon, turning the Show into a fast, private Home Assistant voice satellite with a touch screen of its own.

Why TECHO5

🐧 Real Linux, no Android	The Show boots straight into a minimal Alpine Linux root filesystem. No Android framework, no Google services, no app store: one daemon drives the microphones, speaker, screen, camera and radios directly.
🚫 No Alexa, no Amazon account, no Amazon cloud	Your voice goes only to your Home Assistant, over its encrypted ESPHome API. The Show reaches the internet just for what you use: update checks against this repo, network time, radio streams with their song and cover lookups, and the rain radar map. Voice and control keep working with the internet down, as long as your Home Assistant pipeline is local.
🎙️ Wake word on the device	microWakeWord runs locally: "Alexa", "Okay Nabu", "Hey Jarvis" or "Hey Mycroft", chosen on the screen or in Home Assistant. Echo cancellation keeps it listening over music.
🔐 Secure by default	SSH is keys-only and off until you turn it on; keys arrive only through Home Assistant. The camera and screen web pages start closed. No password logins, not even in rescue.
🔄 Updates that can't brick it	Releases install over the air from Home Assistant's update card into the spare of two root filesystem slots, boot on trial, and fall back on their own if the new one doesn't settle.
📺 A screen that's actually useful	Clock and weather, the conversation as it happens, now playing with song and cover art, forecasts and a live rain radar, live Home Assistant cameras, timers and alarms, Wi-Fi setup, 13 themes.
📻 Weather and radio with no setup	A new Show uses the forecast every Home Assistant has, and lists the radio stations near home from Home Assistant's Radio Browser. Pick another weather entity (your own station, say) on the screen, and keep your own favorite stations too.
⏰ Alarms that ring on their own	Set on the screen, by Home Assistant, or followed from its helpers; they ring from the Show's own clock even when Home Assistant is down. Snooze included.
🎧 Bluetooth, rebuilt	Earbuds and speakers over A2DP, plus a Home Assistant Bluetooth proxy, on a kernel rebuilt with Bluetooth from the LineageOS source.
📷 A camera you control	The front camera becomes a Home Assistant camera entity, off unless something is watching, and physically off while the mute button is engaged.
🛟 Always recoverable	A rescue environment with a USB serial console, and TWRP left in place: LineageOS is one flash away.

Screenshots

Straight from the device's own screen.

Clock, weather and the next alarm	Alarm ringing, big enough to hit half awake
Settings: volume, brightness, Wi-Fi, wake word	Alarms: set on the device, no app needed
Alarm editor with day chips	Security: every open door has a switch
Themes: presets or your own colours

Stock vs TECHO5

	Stock Echo Show 5 (Alexa)	TECHO5
Operating system	Fire OS (Android)	Alpine Linux, one daemon
Voice assistant	Alexa, in Amazon's cloud	Home Assistant Assist, with any pipeline you run
Where your voice goes	Amazon	Your Home Assistant, encrypted
Wake word	"Alexa", processed for Amazon	On the device: Alexa, Okay Nabu, Hey Jarvis, Hey Mycroft
Screen	Alexa cards and ads	Clock, weather, now playing, cameras, timers, alarms, settings
Music	Amazon Music and skills	Home Assistant radio lists with cover art, Music Assistant (Sendspin), Home Assistant media
Timers and alarms	Alexa	Home Assistant timers on screen; alarms that ring without Home Assistant
Camera	Video calls, Drop In	A Home Assistant camera entity, off unless watched
Bluetooth	Speaker and phone audio	Audio to earbuds and speakers; Home Assistant Bluetooth proxy
Smart home	Alexa routines	Everything Home Assistant does
Updates	Amazon, automatic, whenever	From this repo's releases, when you press Install; A/B slots with automatic fallback
Remote access	None	SSH with keys, off by default
Listening on your network	Amazon's services	Home Assistant's encrypted API and the Sendspin player; SSH and web pages only when switched on
Calling, Drop In, shopping, skills	Yes	No. Those are Alexa cloud services

Install

You need a Show 5 2nd gen unlocked with amonet-cronos and running LineageOS 18.1, a USB cable, a Windows PC, and Home Assistant. Each release carries everything else: the boot image and the root filesystem.

1. Copy the root filesystem to the Show with adb and flash the boot image with fastboot.
2. From the USB serial console of the rescue environment, create the slot store and install.
3. Add the Show in Home Assistant with the key it prints. Done: later updates come from Home Assistant.

The whole walk-through, with every command and the fixes for what can go wrong, is in docs/install.md.

Status: in daily use on two Echo Show 5 units. It's a hobby project, not a product: keep your backups, and expect rough edges.

Under the hood

Layer	What
Boot	Amazon's LK, unlocked with amonet; the LineageOS 4.9 kernel rebuilt with Bluetooth; a rescue initramfs that picks a slot
System	Alpine Linux armv7 in two root filesystem slots, read-only, with a trial-and-commit boot counter
Daemon	echod, one Go binary: audio, wake word, echo cancellation, screen renderer, touch, camera ISP, Bluetooth, updates
Home Assistant	The native ESPHome API: voice satellite, media player, camera, update entity, dozens of settings

• docs/overview.md: the one-page description of how it all fits.
• docs/porting-plan.md: how it was built, step by step, dead ends included.
• docs/hardware.md: the cronos hardware and the unlock path.
• docs/camera-research.md: driving the camera's ISP from userspace.
• tools/linux/README.md: building the kernel, boot image and root filesystem.

Sister project

TECHO5 Dot does the same for the Echo Dot 2nd generation: Linux in place of Fire OS, all seven microphones, Bluetooth speaker mode, signed updates. Both run the same daemon source, built per device.

Standing on shoulders

TECHO5 exists because of these projects and the people behind them.

The path here

• EchoLocal (MIT, Yuri Gelfand): the Echo Dot daemon TECHO5's echod grew from, and go-esphome-device, the ESPHome device API it speaks.
• amonet-cronos and kaeru (k4y0z, R0rt1z2): the bootloader unlock and recovery that make any of this possible.
• LineageOS 18.1 for cronos (unofficial, R0rt1z2), built on Amazon's GPL kernel source: the kernel TECHO5 rebuilds and the vendor drivers it keeps. TWRP stays as the way back.
• ShowAssist and the View Assist Companion App (Mark Parker): what ran the Show before TECHO5, and the first proof it could be a Home Assistant satellite.
• jxlarrea/lineageos-echo-show-camera: the OV02B10 camera driver and sensor fixes, the privacy latch, and echo cancellation work on the Echo Show family.
• bengris32/linux-mtk: the mainline MT8163 effort, a map of the hardware.
• The BQ Aquaris E10 GPL source release: MediaTek's ISP register map for this chip generation, which let the camera run from userspace.

What runs on the device

• microWakeWord (Kevin Ahrendt), the ESPHome wake word models, and zserge/microwakeword for Go.
• Home Assistant and ESPHome: Assist, the native API, and the reason to build any of this.
• Music Assistant and Sendspin.
• Radio Browser, through Home Assistant's integration, for stations near home; RainViewer for the radar and OpenStreetMap contributors for the map under it.
• Alpine Linux, BusyBox, Dropbear, wpa_supplicant, BlueZ, bluez-alsa (arkq), and webrtc-audio-processing.
• Go libraries: go-mp3 (Hajime Hoshi), godbus, gorilla/websocket, zeroconf, mewkiz/flac, pion/opus, cobra, viper, protobuf and the Go fonts.

See NOTICE for licenses of code carried in this repository.

The older route: the daemon beside LineageOS

Before the Linux image, the daemon ran as an init service on LineageOS 18.1. That still works, on a unit with USB debugging and rooted debugging enabled:

cd echod
$env:GOOS='linux'; $env:GOARCH='arm'; $env:GOARM='7'; $env:CGO_ENABLED='0'
go build -trimpath -ldflags '-s -w' -o ../bin/echod-arm ./cmd/echod
cd ..
.\tools\install-cronos.ps1 -Serial <adb serial> -Name "Kitchen" -KeyFile .\kitchen.psk

The installer puts the daemon in place as an init service, switches Android to its null audio HAL (the daemon owns the microphone and speaker), provisions the name, API key and wake word models, and reboots. Home Assistant then discovers the device as an ESPHome node; paste the key when asked. Android and any app on the screen keep running, silently.

License

MIT. See LICENSE and NOTICE.

TECHO5 isn't affiliated with Amazon. Echo and Alexa are trademarks of Amazon.com, Inc.