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Gpio read speed (Fez Spider)


#1

What is the highest signal frequency that could be read via Socket Y gpio? Which class should be used for reading, DigitalInput class?


#2

hi,

nobody will answer that question because it is totally irrelevant. Netmf is not a real time system, so it is not guaranteed that you will always read an IO when you want/expect.

Start the other way. What are you trying to achieve, then let people suggest whether they think you can achieve that on a Spider.


#3

I have connected:

  • 4 gpios to FEZ socket 12
  • 7 gpios to FEZ socket 14

Signals on socket 12 changes in the following way: 0001, 0010, 0100, 1000, 0001, … with frequency of 8 kHz. When signal changes at socket 12 I need to read 7 gpios on socket 14.


#4

You probably still need to give a higher level of description of what you want, and whether you think 8khz is your “maximum” rate, and what the impact would be if you didn’t read exactly in this cycle, and what you’re going to do with the data you read every change.

you’re only reasonably new here, so I wanted to make sure you knew that my points here are about Netmf alone; the GHI RLP additions allow you to be more deterministic in this regard.

Out of interest, it seems like your inputs are quadrature encoders?