GPIO pin assignment on 50 pin header

  • On the help page here:

    There is a convenient table of logical pin numbers to expansion connector pin numbers for logical pins 60-63. Is there a table anywhere for the remaining expansion header pins?

    It's kind of hard to hunt down. For example, it says "Fans 3-7 are on the DueX5 and DueX2 expansion boards", but it's not clear to me at all which expansion header pins drive those. My guess is that maybe an SPI bus carries more than one of those signals and they are not visible on the expansion header directly.

    I see pins 0-7 map to heaters 0-7. I see names for Heater3-7 on the expansion headers. Does that mean I can use those as input pins using just M307 to disable the corresponding heater?

    As a feature request, it would be nice to add the logical pin numbers to the pins able to be accessed directly here:

    Thank you for your time,


  • administrators

    The fans on a DueX are controlled over the I2C bus.

    If you don't have a DueX board then you can use the heater 3 thru 7 pins on the expansion connector as outputs.

  • Thanks! Can I use them as inputs as well?

    Something like in the gcode documentation:
    M583 P5 S0 ; Wait for Pin 5 to become 0

    Do commands switch pins' input/output state automatically when using G42/M583?
    Also is there a timeout option for M583 to prevent an infinite loop?

    Thanks again for taking the time!

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