16-channel isolated ±10 V ADC HAT

This HAT is intended as an open Raspberry Pi measurement platform rather than a closed data logger. It combines the TI ADS8686S ADC with multiple industrial-voltage inputs, local storage, networking, triggering and custom software on the Raspberry Pi.

What is being reviewed

This review covers the first hardware revision of the ADC HAT, in particular:

• ADC input protection, filtering and ±10 V signal handling
• reference, regulator and supply decoupling
• isolation boundary and grounding concept
• Raspberry Pi SPI, CONVST and BUSY interface
• connector pinout and practical use in industrial measurement setups

Software, drivers and enclosure design are not part of this review.

Review scope

Please report functional issues, violations of ADS8686S data-sheet requirements and recommendations, and clearly useful improvements.

The first person to identify a confirmed functional hardware bug in this HAT receives one free of charge. A qualifying bug must prevent the intended function from working or violate a data-sheet specification or recommendation.

Specific questions

I would especially appreciate feedback on:

• Is the input protection appropriate for real-world ±10 V signals?
• Are there any ADS8686S data-sheet requirements I have missed?
• Is the isolated-ground and reference-ground routing sound?
• Would you need a different trigger, synchronization or connector arrangement?