I came back to my first attempt with just 4 encoders, no buttons.
This worked with setting MCP23017_ENCODERS_V5TOUCH as I found it in the Wiki.
It was not clear what all these -1 were for, and I was not sure anymore how many there should be.
This brought me to try MCP23017_ENCODERS and omit the -1
And guess what: it worked!
The log showed:
and best of all, there was a reaction to my encoders.
As I am curious and as I suspect the interrupt system of my non working Zynthian to be the problem, I wanted to see the correct interrupt signals on my now working one.
The oscilloscope showed a reaction when turning a knob, and a fast acknowledging with resetting the interrupt pin via I2C I suppose:
