Yes, you can move the motor by hand with actively controlled 0 torque.
In my experience 12N14P (7 pole pairs) is by far the most common for skateboard and drone motors.
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Thanks for the reply.
Your comment make me wonder, that I might have interpreted the specifications on poles of these BLDC motors in data sheets incorrectly.
In “old school” definition of motors, you will say, that such BLDC motors in reality is a synchrone motor with permanent magnets. A 2-pole (one pole-pair) synchrone motor will run 3000 rpm (50 Hz rotation frequency) with a 50 Hz electrical frequency. I think it is correct to assume the same definition for these skateboard motors specifying 14 poles. So my calculation from before is incorrect and the max speed of 6000 rpm should make 700 Hz electrical frequency (not 1400 Hz). Therefore I now doubt, that possible audio noise from the electrical frequency will be a significant issue.
I like to ask a bit about how to get started with programming a STM32 MPU like this. Do you intent to use STlink V3? What kind of programming platform do you use - PlatformIO, Arduino, or something else?
I have seen STlink V3 recommended in this forum. But there seems to more versions of it too.
I have shown this video above, with a DC motor drive using a small brushed DC motor to record speed for a speed controller:
I have just now noticed an issue with using a brushed motor as a speed sensor like that, and it is linked to the behavior of the brushes:
For about a week, I have not been using the motor drive. Then I noticed some errors, when I used the motor and sewing machine at low speed. The software got some error protection code, that can shut off the motor drive. I then made a test to find out the problem. The motor and tacho generator was turning 180 rpm, and I saw a drop out of speed signal for about 4 ms and the behavior of the signal was as the brushes disconnected in the tacho generator (a brushed very small DC motor). 4 ms corresponds to about 4.3 degrees turn of the motor shaft. I have previously noticed short disconnections below 0.5 ms, but not this long.
So it seems that the surfaces of the brushes and commutator might have some oxidation or some dust able to disconnect in short periods. Then I tried to make the motor run at about 6000-10000 rpm for about 15 seconds. After that, I could not provoke this error anymore. It seems like the wear on the surfaces from this treatment made this problem disappear. I have no idea yet how much wear is needed to make the problem disappear.
If you think about using a DC-motor for a tacho generator, then this is a head-up for you. Perhaps you may be able to do some work around of the problem.