StallGuard to detect motion (from standstill)? No.



  • Toying with the idea of adding a stepper motor to a door lock; and the Trinamic range of StallGuard compatible chips could be a good fit to simplify endstops, blocked travel path and manual override.

    But wondering if the TMC2130 or other chips would be able to detect if the lock was actuated manually (external key or internal doorknob) when stationary but energized at a very low current. Then either just update the state or start moving the motor to "assist". Having seen the Watterot videos and looked at the TMC library I would think this is feasible.

    Curious if anyone has done something similar while waiting for the 2130 stepstick (only had 2100 and 2208 on hand).



  • The stallGuard2 measurement value SG is updated with each full step of the motor.

    Confirmed my suspicion, it cannot detect the load when not moving. Encoder it is


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    @bearer said in StallGuard to detect motion (from standstill)? No.:

    The stallGuard2 measurement value SG is updated with each full step of the motor.

    Confirmed my suspicion, it cannot detect the load when not moving. Encoder it is

    That's correct. StallGuard works by measuring the back emf generated by the stepper motor, so it doesn't work at low speeds.



  • Yeah, I noticed, but I was hoping it would be able to determine the load angle when stationary as well. Might poke the various current registers and see if I can spot what I can clearly hear when applying some force to the stationary motor, but looks like no dice indeed.


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