The PiFi DAC+ is a cheap Chinese clone of the HiFi Berry DAC+ Standard made by ukonline2000. It's based on the I2S digital audio converter (DAC) chip PCM5122.
The drivers are already included in the kernel, to activate them check:

• for the 3.12 kernel https://www.hifiberry.com/build/documentation/hifiberry-software-configuration/
• for the 4.x kernel https://www.hifiberry.com/build/documentation/configuring-linux-3-18-x/.
  

It's recommended not to use earphones directly - no headphone amp is build in.

The following GPIOs are used for the Sound Card:
For configuration over I2C:
GPIO2 (SDA 1) and GPIO3 (SCL1

And as the sound interface over I2S:
GPIO18 (PCM CLK), GPIO19 (PCM FS), GPIO20 (PCM D-IN), GPIO21 (D-OUT).
PCM stands for Pulse-Code Modulation.

graphic from: https://indibit.de/category/raspberrypi/

https://www.electrodragon.com/w/images/6/6a/Pcm5102.png

This manual is made by Wolfgang Spahn 2020.
It is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.