linux-voice-assistant/examples/ReSpeaker 2mic HAT/DOCS.md

ReSpeaker 2-Mic Pi HAT

Peripheral controller for the ReSpeaker 2-Mic Pi HAT by Seeed Studio, running alongside the Linux Voice Assistant (LVA) container.

The controller runs as a separate Docker container on the same Raspberry Pi. It connects to LVA's peripheral WebSocket API, drives the 3 APA102 RGB LEDs, and maps the single onboard button to context-aware LVA commands with multipress support.

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Hardware

Component	Details
Microphone array	2 × MEMS mics — MIC_L (left), MIC_R (right) — WM8960 codec, I2S
LED strip	3 × APA102 RGB LEDs in a row
Speaker output	JST 2.0 connector + 3.5 mm audio jack (WM8960 codec)
Button	1 × onboard tactile button (GPIO 17)
Interface	Raspberry Pi 40-pin HAT connector

Compatible hardware

Board	Notes
Raspberry Pi Zero 2 W	Recommended for compact builds
Raspberry Pi 3 B / B+	Fully supported
Raspberry Pi 4 B	Fully supported
Raspberry Pi 5	Requires seeed-voicecard driver compatible with kernel 6.6+ — see Step 1

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GPIO pin mapping

LED strip (APA102)

Signal	GPIO (BCM)	Notes
MOSI (data)	GPIO 10	SPI0 MOSI
SCLK (clock)	GPIO 11	SPI0 SCLK
CE	GPIO 8 (CE0)	/dev/spidev0.0

Button

Function	GPIO (BCM)	Notes
Context action	GPIO 17	Active low, internal pull-up enabled

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LED positions

  ┌──────────────────────────────────────┐
  │  [LED 0]    [LED 1]    [LED 2]       │
  │  MIC_L      centre     MIC_R         │
  └──────────────────────────────────────┘

LED 0 sits above MIC_L and LED 2 sits above MIC_R. When the microphone is muted, these two LEDs turn red to visually indicate the mic positions are disabled. The centre LED (1) is used for general status animations.

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LED animations

LVA state	Animation	LEDs
Not ready / no HA connection	Dim red pulse	All 3
Idle	Solid user color when the LED light is on, else off	All 3
Wake word detected	Flash (×2) in user color	All 3
Listening	Chase (bouncing left ↔ right) in user color	1 at a time
Thinking	Yellow pulse	All 3
TTS speaking	Green breathe (slow sine)	All 3
Muted	Solid red	LEDs 0 & 2 only (mic positions)
Error	Red flash (×3), then off	All 3
Timer ringing	Blue flash (repeating)	All 3
Timer ticking	Dim cyan, brightness ∝ time left	All 3
Media playing	Dim green steady	All 3
Volume muted	Solid red	LED 1 only (center led)

"User color" comes from the Home Assistant Light entity described below (default: HAVPE-style blue). HA brightness scales every animation in this table. Semantic colors (Thinking yellow, Speaking green, Muted red, Timer cyan/blue) are hardcoded so they remain recognisable across user customisation.

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Home Assistant Light entity

On connect the controller registers a Light entity with LVA, which appears in Home Assistant as light.<satellite>_leds. It defaults off, matching the Voice PE LED Ring; turn it on for a solid idle glow and set its RGB color and brightness from the device page.

Effects

Effect	Behaviour
Voice Assistant (default)	Run the pipeline animations from the table above. Wake word and Listening are tinted with the HA color; brightness scales every animation.

Like the Home Assistant Voice PE, this example exposes a single Voice Assistant effect: the pipeline animations always run and can't be switched off from HA. The peripheral protocol itself accepts any number of effects, so your own integration is free to declare more (a color loop, a static accent, and so on) — see the peripheral API docs.

Brightness, on/off, and color

Matching the HA Voice PE LED Ring, the Light defaults off, so the LEDs stay dark while idle until you turn it on; once on, idle shows the solid color, and turning it off again just removes that idle glow. The voice animations always run either way (on/off only gates the idle glow, it does not disable them), so the effect can't be switched off completely. Brightness scales linearly across every animation, and RGB color is the solid idle color and tints the Wake word / Listening animations.

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Button behaviour

The single onboard button supports both single-press context actions and multi-press gestures:

Single press (< 1000 ms hold time)

Context-aware command based on current state, mirroring the Home Assistant Voice PE centre button priority:

Current state	Command sent
Timer ringing	stop_timer_ringing
Wake word / listening / thinking / TTS speaking	stop_pipeline
Music / media playing	stop_media_player
Any other (idle)	start_listening

Multi-press gestures

Detected via press timing within a detection window (250 ms between releases, matching the HAVPE centre button):

Gesture	Timing	Command sent
Double press	2 presses < 250 ms apart	button_double_press
Triple press	3 presses < 250 ms apart	button_triple_press
Long press	Single press held > 1000 ms	button_long_press

Each gesture plays its own short confirmation sound on the satellite speaker so the user knows it was detected. Sound paths are configurable via --button-double-press-sound, --button-triple-press-sound, and --button-long-press-sound.

Multi-press commands are useful for triggering custom Home Assistant automations. For example:

• Double press → start a specific routine or mode
• Triple press → access a menu or configuration option
• Long press → toggle do-not-disturb or night mode

These commands are exposed as button press events to Home Assistant (via the registered button sensor), allowing you to create custom automations via button_press_event triggers.

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Installation

Step 1 — Install the seeed-voicecard audio driver

This must be done on the host Raspberry Pi, not inside Docker.

git clone https://github.com/respeaker/seeed-voicecard
cd seeed-voicecard
sudo ./install.sh
sudo reboot

After rebooting, verify the microphone and speaker appear:

arecord -l
# Should list: seeded-2mic-voicecard

aplay -l
# Should list: seeded-2mic-voicecard

Note: The seeed-voicecard installer also enables SPI automatically. Check /boot/firmware/config.txt after running install.sh before proceeding to step 2.

Pi 5 note: The standard seeed-voicecard repository may not support the Pi 5 kernel (6.6+). Check the seeed-voicecard GitHub issues for a compatible branch or fork before proceeding.

Step 2 — Enable SPI in config.txt

If dtparam=spi=on is not already present in /boot/firmware/config.txt, add it:

dtparam=spi=on

# Also disable onboard audio if you see conflicts:
# dtparam=audio=on    ← comment this out

Reboot and verify:

ls /dev/spidev*
# Should show: /dev/spidev0.0

Step 3 — Add user to GPIO and SPI groups

sudo usermod -aG gpio,spi $USER

Log out and back in. Check your UID:

id -u $USER

If it is not 1000, update the user: field in compose.yml to match.

Pi 5 note: On Pi 5, GPIO is exposed as /dev/gpiochip4 not /dev/gpiochip0. Update the devices mapping in compose.yml:

devices:
  - /dev/spidev0.0:/dev/spidev0.0
  - /dev/gpiochip4:/dev/gpiochip4

Step 4 — File structure

ReSpeaker 2mic HAT/
├── Dockerfile
├── compose.yml
├── requirements.txt
└── respeaker_2mic_hat.py

Step 5 — Build and start

Option A — Run with Docker Compose (recommended)

docker compose up -d

Check logs:

docker compose logs -f

Option B — Run directly with Python

pip install -r requirements.txt
python respeaker_2mic_hat.py --host localhost --port 6055

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Using the speaker output with LVA

The WM8960 codec on the HAT also drives the speaker. After installing seeed-voicecard, pass the device name to LVA:

--audio-output-device "seeed-2mic-voicecard"

Or set the environment variable in LVA's compose file:

environment:
  - AUDIO_OUTPUT_DEVICE=seeed-2mic-voicecard

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Configuration

All configuration is at the top of respeaker_2mic_hat.py:

# LVA connection
DEFAULT_LVA_HOST = "localhost"
DEFAULT_LVA_PORT = 6055

# APA102 SPI
SPI_BUS        = 0
SPI_DEVICE     = 0          # /dev/spidev0.0
SPI_SPEED_HZ   = 8_000_000
LED_COUNT      = 3
LED_BRIGHTNESS = 0.6        # 0.0–1.0

# GPIO button
BTN_ACTION     = 17
BTN_DEBOUNCE_MS = 150

# Button multipress timing
MULTIPRESS_TIMEOUT_MS = 500    # Time window between presses (ms)
LONG_PRESS_MS         = 1000   # Duration to detect long press (ms)

Command-line arguments

Argument	Default	Description
--host	localhost	LVA container hostname or IP
--port	6055	LVA peripheral API port
--debug	off	Enable verbose debug logging

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Drivers summary

Component	Driver needed	Where to install	How
Microphones + speaker (WM8960)	seeed-voicecard	Host Pi	git clone + sudo ./install.sh, then reboot
LED strip (APA102)	SPI overlay	Host Pi	dtparam=spi=on in config.txt, then reboot
Button	None	—	gpiozero + lgpio installed inside container via pip

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Troubleshooting

Microphone or speaker not detected by LVA

1. Confirm arecord -l and aplay -l show seeed-2mic-voicecard on the host.
2. If not, re-run sudo ./install.sh and reboot.
3. On Raspberry Pi 5 with kernel 6.6+, check the seeed-voicecard GitHub issues for a compatible branch.

LEDs do not light up

1. Confirm dtparam=spi=on is in /boot/firmware/config.txt and the Pi has been rebooted.
2. Check /dev/spidev0.0 exists: ls /dev/spidev*.
3. Confirm the container user is in the spi group: groups $USER.
4. Run with --debug and look for APA102 SPI driver opened in the logs. If spidev not found appears, the Python package failed to install — rebuild the image.

Button does not respond

1. Confirm /dev/gpiochip0 (or /dev/gpiochip4 on Pi 5) is mapped in the compose devices section.
2. Run with --debug — each button press logs Button → <command>.

Pi 5 — button not working

On Pi 5, GPIO is on /dev/gpiochip4 not /dev/gpiochip0. Update compose.yml:

devices:
  - /dev/spidev0.0:/dev/spidev0.0
  - /dev/gpiochip4:/dev/gpiochip4

LVA not reachable

1. Confirm LVA is running and --disable-peripheral-api was not passed.
2. With network_mode: host, localhost resolves to the Pi itself.
3. Check port 6055 is not blocked: nc -zv localhost 6055.