Codesys on raspberry pi - I2C with interupt

  • pavel-entry

    pavel-entry - 2021-01-13


    I am trying to connect STM32 (slave) and raspberry pi (master) via I2C. I need Codesys running on raspberry pi to be able to read data from I2C using an interrupt.

    Is it possible? Is there any example? I would appreciate any help.

    I currently use the library to read data in Codesys.


    • Morberis

      Morberis - 2021-01-13

      You're talking about pulling one of the GPIO pins high/low to trigger an interrupt and read something over the i2c bus? I don't believe that interrupts triggered from the GPIO are supported.

  • ojz0r

    ojz0r - 2021-01-14

    Do you perform a cyclic I2C already and it is not enough?
    Or do you only want to read I2C only when there is a change (interrupt) in the slave?
    If its the latter then you can use a GPIO as input to trigger a I2C read as Morberis said.

    • Morberis

      Morberis - 2021-01-14

      Sorry yes that could work.

      I was assuming it was a hardware interrupt that was wanted though if that's not required it could definately trigger a read through a variety of methods.

      My reference for hardware interrupts not being supported is this post here.


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