I am using a Arduino zero clone that uses the nano footprint.
If you only use the SPI interface you only need one input level shifter
At the top of tinyAS.ino are three defines you can comment out to remove display and local UI controlled by the rotary.
I will move the code to GitHub
I should not have removed the parallel pe4302 code. Will repair
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HBTE Files section:?
/g/HBTE/filesErik, PD0EK