Kinetis Microcontrollers中的主题 Re: Quadrature encoder Kinetis k64

Quadrature encoder Kinetis k64

Edrianocarlos — Thu, 31 May 2018 19:24:05 GMT

Hello,

I would like to ask to you guys.

if i have to deal with counters higher than the 65535 from the 16 BITS counter.

how do you normally deal with that? use the overflow interrupt?

what other way can i deal with that without loosing counts?

thank you.

Re: Quadrature encoder Kinetis k64

Robin_Shen — Wed, 06 Jun 2018 03:27:52 GMT

The overflow interrupt should be used to deal with it.
TOFDIR indicates the counting was up when the FTM counter overflow occurred.

Best Regards,

Robin

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Re: Quadrature encoder Kinetis k64

Edrianocarlos — Fri, 08 Jun 2018 12:38:42 GMT

Thanks for your answer.

Yes that is one way i thought how to implement.

My only concern is that lets suppose an overflow happen while i am reading the counter and updating the variable.

as i have a bigger variable i would need to increment it somewhere inside or outside the interrupt handle.

my encoder can generate 1MHz frequency 4 edges.

it is really hard to simulate it and trying to realize if this can even happen.

Re: Quadrature encoder Kinetis k64

Robin_Shen — Tue, 19 Jun 2018 09:13:30 GMT

The KV4x and KV5x contain Quadrature Encoder/Decoder (ENC) module which support 32-bit position counter.

You can check if these MCU meet your needs.

Best Regards,

Robin

Re: Quadrature encoder Kinetis k64

Edrianocarlos — Thu, 21 Jun 2018 00:50:43 GMT

Thank you Robin.

I was able to make this one work.

running the core at 100 Mhz reading the counter and inc or dec one variable.