Uwe Haertel

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5 years, 6 months ago.

FRDM-K64F using SD card and RF/WIFI expansion board, spi conflict?

Hi,

I am trying to use both SD card and RF/WIFI module but this doesn't seem to be possible because of both use the same SPI. Is there a workaround?

1 Answer

Zoltan Hudak
5 years, 6 months ago.

Hello Uwe,

You can have mutliple SPI devices (slaves) connected to the same SPI bus. The master (FRMD-K64F in this case) selects the actual device (slave) by bringing the CS (chip select) line low:

  • PTE4 when communicating with the SD card
  • PTD4 when communicating with the RF/WIFI

(Make sure that only one CS line is low at a time.)