eQEP's maximum input frequency

Hello,

I recently come across eQEP Module. And I’m curious to know it’s maximum input frequency of encoder channel.

Basically, I’m using Pololu’s 50:1 Geared Motor (200 RPM) with Encoder (64 CPR), and I’m not sure if eQEP will support it.

The calculation says that, on one revolution of the motor (the geared shaft) will cause 64x50 = 3200 ticks.
At 200 RPM, it will cause 640k ticks/minute, that makes approx 10.6k ticks/second.

Since the number is too large, I doubt eQEP will be able to keep track of the position. I cannot find a proper document where the maximum speed is stated.

Help will be appreciated.

You could easily count 10 KHz in software using the PRU. The eQEP
modules are typically clocked by 100 MHz clock signal, so I wouldn't
start worrying about the hardware keeping up until you get over 10 MHz
or so on your count frequency.

QEP measurement depends a lot on the quality of the sensor signals. As long as both signals have nearly 50 % duty cycle and the phase shift is near to 25 %, you can measure 10 MHz (as Charles mentioned) and even more. In contrast a bad sensor system can be inaccurate at 10 kHz and below. Ie. bearing slackness can cause significant problems, or vibrations in the range of the sensor disk resonant frequency. (Shouldn’t happen at 200 rpm, but may be an issue when vibrations come from other systems.)