Raspberry Pi and Karaoke Machine (Wolfson Pi Use and its Limitation)

Hello everyone,

This week I’ll post to how to use Wolfson Pi and some limitation that I found in the Wolfson Pi while in use.

As previously said I used the technique explained by Ragnar Jensen. So I have attached the “use_case_script” folder it contains the script which helps in selecting your favourite choice of input and output device.

I have attached the use_case_script folder as archive in the post. Download and extract it in your /home/pi/ .

Now the next step is to select your choice of audio input and output device among the available input and output device.

In my case I have selected the Headset as output device and DMIC as Input for that I open the terminal and enter the following commands

cd ~/use_case_script
./Playback_to_Headset.sh
./Record_from_DMIC.sh

This will select your Headset device as output device and DMIC as your Input device you can also use Headset as input device as well. Or you can experiment with other input and output devices.

To record sound from the DMIC enter the following in terminal

arecord -t wav -d 20 -r 44100 -f dat test.wav

This will record audio with sample rate of 44100 Hz. I don’t know why wolfson pi don’t record 8000Hz or 16000Hz sample rate audio format. And also it doesn’t support 8- bit sample format.

To test the recorded sound file test.wav enter the following in terminal.

aplay test.wav

Other than this I install audacity to experiment with the audio features in the raspberry pi and wolfson pi.

To install audacity enter the following in terminal

sudo apt-get install audacity

Here is screenshot of audacity application which I have installed in my Raspberry Pi. Also you can see the stereo recoreded audio in the screenshot.

But If talking about the limitation according to me when using Wolfson Pi or which I have faced

1. Unable to record 8000Hz/16000Hz sample rate format audio.
2. Unable to record 8-Bit audio format.
3. Unable to run 2 or more sound application using wolfson pi at the same time. (So definitely when I use it in karaoke either I hear music or I can loop back my voice).
   Getting error resource or device busy when using 2 sound instances at same time.
4. And lastly it occupies your GPIO port so that you can unable to connect other devices with it.

If you have any problem and query regarding this don’t hesitate to ask I’ll try my best to answer it. If you have any suggestion’ please comment below.

Regards,

Sumit Rai