Marlin dev-2.1.x with (lots of) TMC2130 shows 'TMC connection error'

Hello all,

I am having some trouble with my RAMPS 1.4 + RAMPSXB +self designed board.
I am trying to run all 9 drivers with TMCs. Chip select signals for them were provided by 2 PFC8574 and a modified TMCStepper library.
This worked great with one TMC + motor.
But placing all drivers in the board(s) got an 'TMC connection error' on the LCD.

I did not test the single driver setup without a motot, so i think the error message just means that the wiring is faulty.

Or am i wrong?

Please help me.

@_juergen_
I'm afraid I can't help you with your problem ... But i´m very interested in your solution ... Can you please share your modified TMCStepper library?
i also want to use 9 TMC2130 drivers on my new printer that i´m planing at the moment ... But i had the idea to use a 4 to 16 demultiplexer for the CS-Pins of the drivers. Maybe your modified code is a good startingpoint for my solution.
My problem is that i´m not good in coding ... I´m an mechanical engineer.

Is the problem perhaps related to the fact that the CS pins of the TMC drivers require an Activ Low? Just an idea.

Hi.

I think it is a timing problem. The cs is via i2c, which happened partially in background (as i (mis)understood the wire lib).
So Marlin more or less often tries to talk to the TMCs via SPI when wire lib is not finished.
So i may have to add a function to get the size of used (send) buffer. If it is 0, wire tx has finished and Marlin can go on.

Only disadvantage: the board is bbiigggg! Arduino, self designed board, RAMPS, RAMPSXB and thousands if sepsticks with its own 'safety board - same size as stepstick). And a great amount auf jumper wires.

Pictures.
First one is the actual setup for my Tronxy X5S.

The other two are 'FrankenRAMPS'-monster...