Review on Enhance Raspberry Pi with High-Precision AD/DA Functions: Raspberry Pi AD/DA Expansion Shield Board featuring ADS1256 DAC8552 Sensor by Douglas Irwin

This is a disaster. Neither ADC nor DAC correspond to the declared properties. The DAC is equivalent to a very noisy 6-bit DAC (not 16-bit); The ADC is better, but still often fails at a fixed input voltage. I have 3 of these and all are bad. They're just not good enough to work in my application. The manufacturer clearly got a bunch of bad silicon and didn't test it very well (or whatever). The manufacturer did not respond to my complaint.