topic Re: Quadrature Encoder speed measurement in i.MX RT Crossover MCUs

Quadrature Encoder speed measurement

dh1 — Fri, 30 Jun 2023 13:37:36 GMT

Hello

In the reference manual of the IMXRT1060X, there is a chapter 56.3.5 Speed Measurement Method, which explains how to measure the speed of a quadrature encoder signal.

Is there a code example available, which implements this algorithm?

Thanks and regards,
Daniel

Re: Quadrature Encoder speed measurement

_Leo_ — Fri, 30 Jun 2023 20:17:11 GMT

Hi,

Thank you so much for your interest in our products and for using our community.

For the Quadrature Decoder (QDC) module, only the SDK examples enc_basic and enc_index_interrupt are available, which only compute position. No examples are available for the Speed Measurement Method.

Sorry for the inconvenience.

Have a nice day!

Re: Quadrature Encoder speed measurement

dh1 — Mon, 03 Jul 2023 06:31:41 GMT

Hi,

Thank you for your answer. That is strange, because the description seems so detailed that somebody must have tested this somehow.

Best regards,
Daniel

Re: Quadrature Encoder speed measurement

dh1 — Tue, 04 Jul 2023 12:27:42 GMT

Hi,

Looking at it again, it seems the "Speed Measurement Method" topic is misleading. It refers to the register POSDPER. But this controller (imx RT106x) does not even have this register?

Or am I overseeing something?

Regards,
Daniel

Re: Quadrature Encoder speed measurement

_Leo_ — Wed, 05 Jul 2023 17:20:55 GMT

Apologies. That's correct, the IMXRT1060 does not support this register. It is an typo that I will report to the corresponding department.

In such a case, you will need to create an algorithm using a general purpose timer as the time base connected to the TRIGGER and take a snapshot of the POSD register in order to calculate speed.

On the other hand, you can use IMXRT1160/70 where it is supported.

Wish it helps you.