STM32L431V LQFP100 problem with SPI2 - MISO

Why you don't use HAL Library?

No, I can't use them in my project (HAL library).

What is the expected SPI_DR content?

Note, that using debugger to observe register content may be intrusive.

Try changing the SCK pin's drive (speed, OSPEEDR) to higher.

Try a conservative data size, e.g. 8 or 16, rather than 4, just to see if there's any significant difference.

JW

changing the SCK pin's drive to higher (Mediu, High, VeryHigh ) - problem remains

changing the size date (8 or 16 bit) - the other device does not respond to given commands

> changing the size date (8 or 16 bit) - the other device does not respond to given commands

For testing SPI (and UART for that matter), it's always better to disconnect "other devices" and loop back Tx to Rx.

So, what is the expected SPI_DR content and what is the received content?

JW

Make sure there is no other part of the SW which reconfigure the GPIO after SPI init...

Also are the SPI2 and 3 same type (some like STM32F437 have high speed SPI1,4,5,6 (div2) and lower speed SPI2,3 (div4)

Are you using interrupts? When copy paste code, sometime not all is converted manually...

I test Tx connect to Rx, SPI2 worked properly. The mistake was third device on SPI BUS. The third device was still active (CS).

Thank you for your advice