AnsweredAssumed Answered

STM32F4 HAL SPI NSS won't work with baudrates below 1 MBaud

Question asked by Fusswinkel.Nils on Feb 11, 2017
Latest reply on Feb 13, 2017 by Fusswinkel.Nils

Hi,

 

I'm trying to set up a SPI connection for an AS5311 sensor on my STM32F405. I want to use the hardware controlled NSS signal, which is working pretty well - but only for high baudrates.

 

I am using CubeMX to configure my clocks and peripherals. If I set the baudrate above 1 MBaud and read the sensor data with the HAL_SPI_Receive_IT(...) function the NSS signal is used properly. But if I change it to a baudrate below 1 MBaud, NSS is not working anymore. I do not change anything on my source code. I olny use the prescaler setting for SPI in CubeMX.

 

Does anyone know the reason for this? Unfortunatly the sensor does not support baudrates above 1 MBaud. See the pictures below to comprehend my problem

Outcomes