Remora - Rpi Software Stepping Using External Microcontroller via SPI

I made some progress, SPI wasnt likely working properly before, as I had chosen PB9 for the pru-reset. Turns out PB9's timer is already occupied so no PWM. I change to PB15 which is usable for PWM and now i'm getting a 

When trying to unlock the e-Stop.

I just realised I still had SPI_clk_div set to 16, after setting it back to 32 or 64, the errors are gone, but i'm at square one again, no error on e-stop deactivate.

the fact that you get a bad spi payload is good, keep it at 32 probably

This may sound forward of me, but how long is your cable?

About 8cm-ish. pretty standard dupont wires for breadboards

those wires look too long and too loose. you will need to shorten them for sure and tighten them up a big
shorter is better, keep it as short as possible
edit do you mean 8inches and not 8cm? 8cm is the length of the rpi board

They were actually 10cm, now they are closer to 4. Unfortunately wasnt the (root) cause of my issues.