HiveMind Microphone Satellite

hivemind-mic-satellite is the smallest HiveMind satellite. It runs only a microphone plugin and a VAD (voice activity detection) plugin on the device.

Audio streams from this device to a HiveMind server that runs hivemind-audio-binary-protocol. The server handles wakeword detection, speech-to-text, intent processing, and text-to-speech synthesis. The satellite receives the synthesized speech audio and plays it back locally. No local STT or TTS models are needed, so the satellite can run on cheap, low-power hardware such as a Raspberry Pi Zero.

---

Satellite spectrum: where does processing happen?

Satellite	Mic	VAD	Wakeword	STT	TTS	Best for
HiveMind-cli	n/a	n/a	n/a	n/a	n/a	Text-only (keyboard/script)
hivemind-mic-satellite (this repo)	local	local	server	server	server	Cheapest hardware / homelab; no local models
HiveMind-voice-relay	local	local	local	server	server	Local wakeword; scales as a service
HiveMind-voice-sat	local	local	local	local	local	Full local stack, sends text

---

Server requirements

The default hivemind-core does not include audio processing. Install hivemind-audio-binary-protocol on the server to enable server-side wakeword, STT, and TTS.

---

Why mic-satellite, and when not to use it

mic-satellite exists for one reason: device resources. With only a microphone and VAD on-device, it runs on cheap hardware, such as a Raspberry Pi Zero or a recycled phone, with no local models. The hive owns everything else: wakeword, STT, intent, and TTS. It gates them behind the same access-key authentication as the rest of the mesh. The hive operator chooses the engines, models, and voice for every connected satellite. A satellite cannot override them. This is the same ownership model as voice-relay. See its docs for the "HiveMind as a service" framing.

There is a trade-off. Because there is no local wakeword, the satellite streams every detected voice segment upstream (gated by VAD, not by a wakeword). This continuous audio stream uses more bandwidth and puts the full STT load on the server for all speech, not just commands. This works well for a homelab with a handful of personal devices, where on-device resources are the binding constraint. It does not scale for HiveMind-as-a-service across many tenants, because streaming raw audio per client costs too much. For a service-style deployment, prefer voice-relay: a local wakeword means audio leaves the device only after activation.

---

Install

pip install hivemind-mic-satellite

Requires Python 3.10 or later.

---

Quickstart

1. On the hive (server): create an access key for this device:

hivemind-core add-client --name my-mic-sat
# note the access_key and password printed

2. On the satellite device: set the identity:

hivemind-client set-identity \
  --key <access_key> \
  --password <password> \
  --host <hive-host-or-ip>

3. Run:

hivemind-mic-sat

Or pass credentials directly without storing them:

hivemind-mic-sat --key <key> --password <password> --host <host> --port 5678

---

Minimal configuration

The satellite shares the standard OpenVoiceOS config file ~/.config/mycroft/mycroft.conf. At minimum you need a microphone plugin and a VAD plugin:

{
  "microphone": {
    "module": "ovos-microphone-plugin-alsa"
  },
  "VAD": {
    "module": "ovos-vad-plugin-silero"
  }
}

See docs/configuration.md for all options, plugin selection, and audio device tuning.

---

Supported plugins

Plugin type	Required	Purpose
Microphone	Yes	Captures audio from hardware
VAD	Yes	Detects voice activity, decides when to stream
PHAL	No	Platform/hardware abstraction (for example LEDs, buttons)
TTS Transformers	No	Mutate TTS audio before playback
G2P	No	Visemes for mouth movement (for example Mycroft Mk1)
Media Playback	No	Media commands such as "play Metallica"
OCP Plugins	No	URL playback (YouTube and similar)

---

Features handled server-side, not on this device

• STT (speech-to-text)
• TTS (text-to-speech) synthesis
• Wakeword detection
• Continuous listening, hybrid listening, sleep mode, recording mode
• Multiple wakewords
• Audio and dialog transformer plugins

---

Documentation

Full documentation is in docs/:

• Overview and satellite spectrum
• Getting started
• Configuration reference
• Architecture (advanced)
• Deployment (systemd, Raspberry Pi)
• Testing (e2e suite, mocked hardware)
• Troubleshooting

---

Related

Project	Role
HiveMind-core	The hive, manages connected satellites
hivemind-audio-binary-protocol	Server-side audio processing (required)
HiveMind-voice-relay	Satellite with local wakeword
HiveMind-voice-sat	Full local stack satellite
HiveMind-cli	Text-only satellite
ovos-plugin-manager	Plugin framework (microphone, VAD, PHAL, and more)

---

License

Apache-2.0: see LICENSE.