Install Voicecard software
Make sure you've got the BrainCraft HAT or Voice Bonnet installed, and I2C support installed as well!
When you run
sudo i2cdetect -y 1
you should see an entry under 1A, indicating the hardware sees the audio card. The number may also appear as UU if you already installed software
Do not install this on the Desktop Version on the Pi 5, as the desktop will completely stop loading after installation! Bookworm Lite has been tested and works.
At the command line run:
cd ~ sudo apt-get install -y git git clone https://github.com/HinTak/seeed-voicecard cd seeed-voicecard git checkout v6.6 sudo ./install.sh
At the end you should see something like this:
Reboot with
sudo reboot
sudo aplay -l
To list all sound cards, you should see it at the bottom
On a Raspberry Pi 2 or 3, your card number may be Card 2 instead of 3 because it only has a single HDMI port. You'll need to make some changes to some of the commands to reflect this further down.
If your card number differs from the above image, take note of your number.
You can use alsamixer
to adjust the volume, dont forget to select the card with F6
A gain of about 60% is plenty loud!
Headphone/Speaker Test
Make sure the Audio On/Off switch is set to ON!
With either headphones plugged into the headphone jack or a speaker attached to the speaker port, run
speaker-test -c2
you will hear white noise coming out of the speakers/headphones! If you don't hear anything, you may need to change the -c
parameter to match the card number of your device.
Microphone Test
There are two microphones, and now we can test that they work. This test is best done with headphones, not using the speaker port, because it can cause a painful feedback effect if the speakers are next to the mics!
Run:
sudo arecord -f cd -Dhw:3 | aplay -Dhw:3
If your sound card ID is not #2, then replace the number in both of the -Dhw:
parameters with your actual number.
Then either gently rub each microphone, or speak to hear yourself echoed!
Control-C
to quit when done
Your audio subsystem is now completely tested!
Python Libraries
The Microphone and Voice Card are installed as Linux level devices, so using them in is done as you would with any system level audio device. If you would like to make use of audio in Python, you can use the PyAudio library. To install pyaudio and its dependencies, run the following code:
sudo apt-get install libportaudio2 portaudio19-dev sudo pip3 install pyaudio
Python Usage
Here is a basic test script to enumerate the devices and record for 10 seconds. When prompted, choose the device called seeed-2mic-voicecard.
Copy and paste the following code into a file called audiotest.py.
import pyaudio import wave FORMAT = pyaudio.paInt16 CHANNELS = 1 # Number of channels BITRATE = 44100 # Audio Bitrate CHUNK_SIZE = 512 # Chunk size to RECORDING_LENGTH = 10 # Recording Length in seconds WAVE_OUTPUT_FILENAME = "myrecording.wav" audio = pyaudio.PyAudio() info = audio.get_host_api_info_by_index(0) numdevices = info.get('deviceCount') for i in range(0, numdevices): if (audio.get_device_info_by_host_api_device_index(0, i).get('maxInputChannels')) > 0: print("Input Device id ", i, " - ", audio.get_device_info_by_host_api_device_index(0, i).get('name')) print("Which Input Device would you like to use?") device_id = int(input()) # Choose a device print("Recording using Input Device ID "+str(device_id)) stream = audio.open( format=FORMAT, channels=CHANNELS, rate=BITRATE, input=True, input_device_index = device_id, frames_per_buffer=CHUNK_SIZE ) recording_frames = [] for i in range(int(BITRATE / CHUNK_SIZE * RECORDING_LENGTH)): data = stream.read(CHUNK_SIZE) recording_frames.append(data) stream.stop_stream() stream.close() audio.terminate() waveFile = wave.open(WAVE_OUTPUT_FILENAME, 'wb') waveFile.setnchannels(CHANNELS) waveFile.setsampwidth(audio.get_sample_size(FORMAT)) waveFile.setframerate(BITRATE) waveFile.writeframes(b''.join(recording_frames)) waveFile.close()
Run the code with the following command:
sudo python3 audiotest.py
When finished, you can test playing back the file with the following command:
aplay myrecording.wav
Page last edited September 25, 2024
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