Measuring motor speed

[Ether]

Originally Posted by iambujo

FYI - I just tested our Hall Latch sensor with a ring magnet on a Fisher Price 00801-0673 motor shaft. I got the motor up to max free speed (12V from a bench supply), and the sensor read 20220 RPMs

How were you decoding the sensor signal?
e.g. did you have the FPGA setup to measure rising edges only, or both rising and falling?

The duty cycle was about 45% regardless of the motor speed so I figure that's based on the ring magnet's pole alignment.

Most likely. Were you able to measure any jitter using the logic analyzer?

I feel the US1881 is an excellent device for measuring wheel/shooter/shaft speeds at pretty much any speed we could ever want.

Indeed