It has only taken me much of the day to get it working. Hours spent reading documentation, searching for postings on the same issue, ripping up the code and trying completely different approaches. Hours of frustration mixed with some solid learning.
Victory was seen in three bytes.
Three bytes shown on the logic analyzer display and in the Python console window. The same three bytes… The hardware and software agreed. The serial timing also looked great, chip select going low when it was supposed to, a 500kHz clock, all of the edges just as the data sheet specified.
Victory is connecting an eight channel A/D converter IC to a Raspberry Pi computer with the hardware SPI module. Four channels for voltages, four channels for temperatures. The project is coming along nicely. Will talk about what in a later posting. Meantime my thanks to Connor Wolf, Louis Thiery, and Brian Hensley. It was their method and SPI code that worked!
A small victory, another step forward, this is what hackers and makers do…