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

Pros: - 24-bit resolution - Assembled construction feels solid - Easy to use once you know what to do Cons: - Documentation definitely needs some work. - I don't seem to be getting the full range - SETUP documentation certainly needs some work. It roughly describes how to set things up in C, but often says "just go to google to understand that part" (I think that was mostly due to the hassle of translating the technical instructions), or a step said me to try run"make" in a folder that doesn't contain a makefile. What was also missing was how to do things in Python. Basically I looked through the files contained in the High Precision AD DA Board repository/archive and found some Python examples. They weren't running locally, so I just moved the files to another folder and completed them by doing a pip install for all the missing packages. But voila, it worked! No additional special proprietary libraries are required, the ADS1256.py and config.py files must be included in the main program file, and then the GPIO and SPI libraries. And the fact that it's running in Python I was expecting pretty poor performance, but it samples pretty quickly if you set it up properly and scan channels at the same time. I'll have to see if this is fast enough for my averaging applications. As for the signal, expect noise. This is not strictly a product comment, just a comment on 24-bit ADCs. In 24-bit mode, the ADC transmits 256 values if you just look at it from the wrong perspective. My biggest concern is that if I pull one of the pins to ground it's still stuck at an ADC value of around 1,600,000. ten%. And then if you pull up to 5V with VCC on 5V it only shows about 8,000,000 or 50%. That means I'm getting less than half my range and not going below 10%. I can work around this of course since I'm already using the code to calibrate my sensors, but I feel like I'm either missing something or there's something wrong with my board.