Thanks for your help so far. We upgraded to a Pi 4 and it works now.
I downloaded the Waveforms SDK and tried some of the test python scripts. Some work, others result in a segmentation fault. One that works is the test_temperature.py, which appears to measure the board temperature of the the Discovery. For some of the others, I stepped through the python code and when the device is opened, the device name is blank. I also see an enumeration in device.py that does not include the "Analog Discovery 3", which is what I have. What is the device name that is supposed to be reported with this device? Have the test scripts been updated for the 3 model or do I need another version of the SDK?
From device.py:
device_names = [("Analog Discovery", constants.devidDiscovery), ("Analog Discovery 2", constants.devidDiscovery2), ("Analog Discovery Studio", constants.devidDiscovery2), ("Digital Discovery", constants.devidDDiscovery), ("Analog Discovery Pro 3X50", constants.devidADP3X50), ("Analog Discovery Pro 5250", constants.devidADP5250)]
Thanks for any help.