STM32L4R9 Discovery Kit---SPI Communication from FAN-OUT Expansion Board to STM32L4 board not happening

[AGumm]

Am Working with STM32L4R9 Discovery Kit

• Trying to connect our module to STM module with FAN-OUT Expansion Board (using SPI interface)
• Generated the code from STMCUBE with following specs
  • SPI Pin connections
    • MOSI----PIN_15/GPIOB
    • MISO----PIN_14/GPIOB
    • CS--------PIN_6/GPIOB
    • SCK------PIN_13/GPIOB
  • Without DMA
  • NSS signal software
• SPI data exchange not happening (DR is always zero)
• Can you pls share the default SPI code
• Suggest me about CS how to configure

[S.Ma]

Open the user manual https://www.st.com/content/ccc/resource/technical/document/user_manual/group0/ae/a3/af/94/27/d8/46/3f/DM00421316/files/DM00421316.pdf/jcr:content/translations/en.DM00421316.pdf

Page 53:

By default in this board, the USART is by default connected to STMod+

To have the SPI connected, the solder bridge 21 17 and 19 must be short.

Otherwise, a mux device is present according to the note in case soldering is to be avoided.

The solder bridges (SB) are available on PCB to select chosen Port, but they are not used by default: Instead of SB, an embedded SPDT quad switch is used to select Port. It is controlled by 2 GPIOs from the MFX_V3 Expander (STMOD+_SEL_0 and _1), please see Table 32 description below (Bold text is default configuration to support MikroBUS modules using MB1280 fan-out board)