SD card pins



  • Hello, I have a WiPy 3.0 on an expansion 3 board. I have used pretty much all the GPIO on my external opti-isolator and v-divider circuits, along with a CAN module. Attached photo may help my explanation.Schematic comp.png

    I would also like to have datalogging capability using the SD-card slot on the expansion board.

    My questions:

    1. When reading similar threads I have read about using a 10k pullup on P8. However at https://docs.pycom.io/firmwareapi/pycom/machine/sd/ it states: "P8: DAT0, P23: SCLK and P4: CMD (no external pull-up resistors are needed)". Is this only required if only using the battery charging capability (which I do not need)?

    2. The pinout (https://docs.pycom.io/datasheets/development/wipy3/) shows 2 additonal SD data pins Data 2 and 3. Can I use DO on these 2 pins or do I need to keep them free?

    3. Can anyone explain whether its possible to use any of the 3 pins (P8: DAT0, P23: SCLK and P4: CMD) as DO or ADC while also using SD card functionality? Even if this means changing pin modes intermittently, providing this doesnt take too long.

    Many thanks for any input given.


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