Different pins for SPI1 in NUCLEO-STM32F401 and the STM32F401RE MCU

[Dimitris Paraskevopoulos]

Posted on December 12, 2014 at 15:27

Hi all,

I am new to this STM32 chip and I was checking out the datasheets and the CubeMX tool and I noticed something weird.

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00102166.pdf

 page 42

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/user_manual/DM00105823.pdf

 page 40In the MCU datasheet CS for SPI1 is PA4 while in the Nucleo CS or NSS for SPI1 is PB6. What is the reason for this change? What is the pin that I should use when trying out the SPI1?Also when trying the CubeMX it also displayed the NSS chip select as PA4 instead of PB6. #nucleo-stm32f4-spi1-cubemx

[waclawek.jan]

Posted on December 12, 2014 at 17:03

Well I believe what in NUCLEO documentation is described as SPI1_CS is *NOT* SPI1_NSS, but simply a GPIO used in the software to frame the SPI transfers (btw. SPI in 'F4 set as master can't manage NSS (as output)).

To confirm, look its function up in the accompanying software (i.e. ''Cube library'') - I'm not going to go through that mess just because of this. JW