Unable to detect stall condition of stepper motor using powerSTEP01 Voltage Mode

[shrikant_swami]

Currently we are evaluating voltage mode feature of powerstep01

Motor Parameters:

Motor Phase Resistance: 8.4 ohm

Motor Phase Inductance: 5.2 mH

Ke: 0.07392

We have tested voltage mode by changing current from 0.5 to 1.1 A. Test report are attached

Also In application we are operating motor from 2 to 14 RPM

Kindly share your feedback on test result and test procedure.Please go through it. Let me know anything is required.

[Cristiana SCARAMEL]

Hello @shrikant_swami​,

The embedded stall detection is not able to discriminate between running and stall motor when there is a small current difference between the two cases.

Moreover, in your solution the target current is very low compared to the capability of the IC and it could be difficult to set a reliable threshold.

You can overcome this issue adding a shunt resistor on the SENSEx pins, even if operating in voltage mode, increasing the drop measured by the stall detection circuitry.

[Cristiana SCARAMEL]

Hello @shrikant_swami​,

have you had a chance to test the suggested changes?

[Gostervall]

@Cristiana SCARAMEL :

> The embedded stall detection is not able to discriminate between running and stall motor when there is a small current difference between the two cases.

I was hoping to be able to use stall detection to (relatively slowly) drive a motor to its end position, smoothly. Like a 3D printer does.

My first approach was to test different STALL_TH values, and find the sweet spot with trial and error.

However, at value `n` for STALL_TH the motor does not move at all (stalling directly), and at value `n+1` it smashes into the end position too hard and for too long. I'm using the X-NUCLEO-IHM03A1 devkit, but I have shorted the SENSE resistors.

Does the quote from your reply above implies that I am attempting something that the PowerSTEP01 cannot achieve? If not, what should I do to smoothly detect end positions? I've tried to reduce the KVAL_* values and see if reduced current would help, but now I'm down to 1 or 2 in STALL_TH.