FAQ & troubleshooting

Which Raspberry Pi do I need?

A Pi 5 (8 GB) is ideal; a Pi 4 (4 GB+) works but the LLM is slower. Use an active cooler and the official power supply — undervoltage throttles inference. See hardware.

No audio in or out

List devices with arecord -l / aplay -l, set device (e.g. plughw:1,0) in your config, and test: arecord -d 3 -f S16_LE -r 16000 -c 1 t.wav && aplay t.wav.

It never stops recording (sox VAD)

The VAD stops after ~1.5 s of silence by default. Raise the threshold or reduce background noise; or switch to the fixed-length arecord recorder.

Replies are too slow

Use a smaller LLM (llama3.2:1b) and a smaller whisper model (tiny.en/base.en). Latency is dominated by the LLM on a Pi.

Does it really run offline?

Yes — once whisper.cpp, an Ollama model and a Piper voice are installed, no network is needed. The demo-worthy moment is unplugging the network and asking again.

How do I run it at boot / see logs?

Install the systemd unit (systemd/whispa-pi.service), sudo systemctl enable --now whispa-pi, and watch journalctl -u whispa-pi -f.

Can I add a wake word or a button?

Yes — drive appliance.runOnce() from openWakeWord or a GPIO button. See upgrades.