HiFiBerry 2×2 Add-on for DAC+ ADC
The HiFiBerry DAC/ADC addon for the DAC+ DSP adds 2 analogue input and 2 analogue output channels to your DAC+ ADC. This document shows how to get started with it.
Unpack the DAC/ADC add-on board
In the box your will find the add-on board, a ribbon cable and long standoffs.
Add the 2×8 pin header to the DAC+ DSP
The DAC+ DSP doesn’t come with the extension header that is needed to connect the extension board. Therefore, you have to solder a 2×8 pin header. If you don’t have one at hand, you can just buy a 2×20 pin header and cut it down to 2×8 pins. Check the solder connections as this is usually the part that causes most trouble.
Mount the DAC+ DSP and connect the ribbon cable
Now put the DAC+ DSP on top of your Raspberry Pi, fix it with the long standoffs and connect the ribbon cable.
Mount the DAC/ADC add-on on top of it
It is usually easiest to first connect the ribbon cable and then mount the add-on board on top of the DAC+ DSP.
You need a phone-jack to RCA cable. Connect this cable to the input and outputs of the add-on board. Basically you create a loop from the output to the input that will allow our test tool to test both input and output.
Connect your amplifier as usual to the stereo output on the DAC+ DSP (not on the add-on board).
Now, download the test image, extract it, write it onto an SD card and boot from it. You should now hear a test tone on your speakers. If you disconnect the loop cable on the add-on board the test tone will stop.
Create new DSP programs to use the additional channels
You can now go on and design the DSP program with the additional input- and output channels. The 4-channel projects on our Github repository are a good choice to start.