I have a Mega, running GRBL v1.1 for Mega, a Protoneer CNC shield (only X & Y axes), 2 TMC2130 step drivers, using LaserGRBL software for testing. My problem: the test motor works (i.e. jogs) when plugged into the Y step driver, but not the step X driver. What I've done:
- Set Vref on both step drivers correctly for the motor
- replaced the X driver with another TMC2130 to make sure it's not the X step driver
- checked connectivity between TMC2130 motor outputs and the stepper cable
- in GRBL, re-assigned X/Y step/dir to different pins; result Y still works, X still doesn't; inspired by this post: Arduino forum
- checked voltages on the X step driver: they're the same as on the Y driver (VIMOT 12V, VCC 5V, cfg pins open)
- right now, the X/Y limit switches are both unconnected, their pin state is the same (HIGH)
Any other suggestions how to diagnose this?