Need Help - Duet WiFi Additional Drivers

Neonode

Hello,

I have build my own pcb for two additional drivers TMC 2660-PA (same as original). Pinout and the overal PCB design is exactly as Duex2 but with removed unnecessary components alike end-stops and mosfets for extruder and etc. I just need two driver and compact pcb. Unfortunately Duex is really big and can't fit for my purpose.

I have a problem with SPI, Duet do not detect the drivers neither try to select them. What I need to do in order to make Duet to search for those drivers same as it do for Duex2. How Duet identify that Duex card is attached ? As I use TMC 2660-PA I would like to use STallGuard for switch-less homing of my additional axis and to control current and micro-stepping trough the firmware.

Regards,
George

dc42

Two ways:

Modify the firmware, changing it to set variable numSmartDrivers to 7 even when no DueX board is detected; or
Add a SX1509B chip to your add-on board wired with the same address select and fixed input that the DueX2 has. The firmware checks for the presence of the SX1509B and reads from it to determine what expansion board is present.