As with video signals, the Pi has several options for outputting audio.
The most widely used is the 3.5mm audio/composite jack. As described above, this jack is capable of outputting both composite video and a stereo output. This is the most common and easiest solution for connecting your Pi to your stereo or audio device.
Another option is outputting audio via the HDMI interface. This however requires a device capable of audio pass-thru and not something commonly found in an automotive setting so I won’t go much into it.
A third option only available if you are using the Pi 3 is Bluetooth streaming. The Pi 3 was the first model to offer built in Bluetooth connectivity. This allows the Pi to connect wirelessly to other devices such as portable speakers, mobile devices, laptops and some car stereos with built in Bluetooth.
The way I recommend people interface their Pi audio wise with their head unit is using the 3.5mm cable to their car stereos aux input.
Changing the audio output
Open up raspi-config by entering the following into the command line:
This will open the configuration screen:
Select Option 8
Advanced Options and press
Enter, then select Option A6:
Audio and press
Now you are presented with the two modes explained above as an alternative to the default
Auto option. Select a mode, press
Enter and press the right arrow key to exit the options list, then select
Finish to exit the configuration tool.