This is the README that was included with the software I got when purchasing this A/D board for my RPi: https://amzn.to/2IQ8BSU
Codes to perform Analog to Digital(ADC, using ADS1256 circuit) and Digital to Analog (DAC, using DAC8552) based on Raspberry PI extended with Waveshare High-Precision AD-DA raspberry pi hat/shield.
The provided codes with the hat/shield was not satisfying (IMHO). These codes are cleaner, faster and meant to be used in other projects (as you have a lib
AD-DA-WS-RPI with proper CMakeLists and Find.cmake to compile it).