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SPI not working

Guenter
2019-01-03
2019-02-14
  • Guenter - 2019-01-03

    Hello

    I want to connect a MCP23S17 device with SPI.
    The CSL0 pin is working but the SCLK stays on LOW level
    At the Raspberry Board the SPI is enabled,

    Any idead what I do wrong?

    Regards

    Guenter

     
  • eschwellinger

    eschwellinger - 2019-01-04

    Hi,
    a known issue on RASBIAN is:
    You need to reduce the max SPI Speed see screenshot

    BR
    Edwin

    IMG: SPIMaxSpeed.png

     
  • elconfa - 2019-02-13

    Hi, I have some problems using the MCP23S17 chips.
    I only connected one chip, but the PLC seems to see them all connected ... How can I eliminate this problem?

    Thanks in advance
    Massimo

    IMG: Cattura spi.JPG

     
  • elconfa - 2019-02-14

    I have another question:

    using i2c port, if an expansion is disconnected, it is possible to reconnect the expansion.

    Using SPI, disconnection of an expansion force me to reboot plc to reconnect to MCP23s17.

    Does it is possible to reconnect without reboot the plc?

    Thanks

     

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