raspberry-piPorcupine - Raspberry Pi Quick Start

  • Wake Word Detection
  • Hotword Detection
  • Voice Commands
  • Always Listening
  • Raspberry Pi
  • Python
  • C

Requirements

  • Python 3

Compatibility

  • Raspberry Pi (all variants)

Microphone Setup

Connect the microphone and get the list of available input audio devices:

arecord -L

The output will be similar to below

null
    Discard all samples (playback) or generate zero samples (capture)
default
mic
sysdefault:CARD=Device
    USB PnP Sound Device, USB Audio
    Default Audio Device
hw:CARD=Device,DEV=0
    USB PnP Sound Device, USB Audio
    Direct hardware device without any conversions
plughw:CARD=Device,DEV=0
    USB PnP Sound Device, USB Audio
    Hardware device with all software conversions

In this case, we pick plughw:CARD=Device,DEV=0. Note that this device comes with software conversions which are handy for resampling. In what follows we note this value as ${INPUT_AUDIO_DEVICE}.

create ~/.asoundrc

pcm.!default {
type asym
capture.pcm "mic"
}
pcm.mic {
type plug
slave {
pcm ${INPUT_AUDIO_DEVICE}
}
}

If you have a speaker add a section for that to ~/.asoundrc as well.

Check if the microphone works properly by recording audio into a file:

arecord --format=S16_LE --duration=5 --rate=16000 --file-type=wav ~/test.wav

If the command above executes without any errors, then the microphone is functioning as expected. We recommend inspecting the recorded file for recording side effects such as clipping.

Installation

The core of the wake word engine is shipped as a pre-compiled ANSI C library. Hence, it can be used within a C/C++ application directory or in a high-level language such as Python via its bindings.

Python

Install PyAudio:

sudo apt-get install python3-pyaudio

Then install the PIP package:

sudo pip3 install pvporcupine

Run the following in the terminal

pvporcupine_mic --keywords porcupine

The engine starts processing the audio input from the microphone in realtime and outputs to the terminal when it detects utterances of wake-word "porcupine". You can learn about the capabilities of pvporcupine_mic by running pvporcupine_mic --help from the terminal.

C

Install ALSA development library

sudo apt-get install libasound-dev

Clone the repository

git clone https://github.com/Picovoice/porcupine.git

Compile the C demo application

gcc -O3 -o demo/c/porcupine_demo_mic -I include/ demo/c/porcupine_demo_mic.c -ldl -lasound -std=c99

Replace ${CPU} in the command below based on the trim of Raspberry Pi (cortex-a72 for Raspberry Pi 4, cortex-a53 for Raspberry Pi 3, cortex-a7 for Raspberry Pi 2, and arm11 for the rest) and run the demo

demo/c/porcupine_demo_mic lib/raspberry-pi/${CPU}/libpv_porcupine.so lib/common/porcupine_params.pv \
resources/keyword_files/raspberry-pi/porcupine_raspberry-pi.ppn 0.5 ${INPUT_AUDIO_DEVICE}

The engine starts processing the audio input from the microphone in realtime and outputs to the terminal when it detects utterances of wake-word "porcupine".

Custom Wake Word

You can create custom Porcupine wake word models using Picovoice Console.


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