Issue with communication in UART mode (more than 4 TMC2209 drivers)

[Coatl1987]

Good evening.

Apologies if the topic has been resolved already but I couldn't find anything regarding my issue.

I'm building a robotic arm based on MOVEO open source project but with 6 axis control (plus extruder) and want to use it as a 3d printer. It's a project for my engineer degree. For my project I'm using TMC2209 drivers with Octopus v1.1 board and marlin version from BTT Octopus GitHub as Kipper didn't work for more than 3 axes.

Managed to add all axes to marlin software so I'm able to move each of them separately but sensor less homing isn't working and I think what's the issue.

As marlin introduced by BTT can setup up to 4 drivers on one port in #define n_SLAVE section and the software requires a port for each driver on LOW I can't communicate with all drivers.

Got some solutions but none of the ones that I found worked for me.

Can anyone let me know either how to solve communication error or how to setup 3 additional drivers for axis I, J and K so they will use the stallguard setting as well.

Much appreciate any advice on this.