Duex5 Fan / LED connections. Vcc or "gnd" switched?

  • Googled a bit, didn't find an answer or schematic. Thought it best to just ask.

    Are the 5 Fan / LED connections on the duex5 Vcc or GND switched? My RGB LED strips are common annode, so hoping they are GND switched like most everything else. 🙂

    On a side note, has anyone looked into adding WS2812 or APA102 / SPI support? I assume either of these would need to be in the firmware itself as I'm unfamiliar if there's hardware support for SPI?

    WS2812 obviously would be a firmware only thing.

    Thanks all!


  • administrators

    The ground connections of the fan outputs on both the Duet and DueX5 are switched. The schematic for the DueX5 is at https://github.com/T3P3/Duet/blob/master/Duet_Expansion/Duex5v0.7/Duex5_Schematic_V0.7.pdf.

    There is a shared SPI bus available, used for communicating with thermocouple and RTD interface boards, and a driver for it in the CoreNG project. It has 3.3V signal levels, so you would need to level shift them to 5V to drive the APA102.

  • Thanks Dave!

    Where can I find the docs on the SPI? Easier to read those than ask my questions here. Specifically looking for pins, slave select info, gcode -> SPI signals, etc…

  • administrators

    There are no gcodes to send SPI signals. I'm not sure that it would be practical to define any, because SPI peripherals vary so much in what data they expect and what they return. Maybe it would be practical for simple output-only devices.

    If you are not using thermocouple or pt100 interface boards then the easiest place to pick up the SPI signals is probably the header that the daughter boards plug into.

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