I created a project in CubeMX for a STM32F429IGtx with SDIO and FatFs. Clock at 180 MHz,
The example works fine in 1 bit mode, but when I switch to 4 bit mode by adding the define "BUS_4BITS"
it does not work and f_write returns an FR_DISK_ERROR. Have switched to DMA, seems to work only with DMA,
but not reliably.
I found an example: STM32Cube_FW_F4_V1.16.0 -> STM324x9I_EVAL that works fine in 4 bit mode.
I have tried to set the pullups in the CubeMX example, but nothing works. I can not see whats really the difference
exept a different initialization order.
Does anyone have an idea? What are the pitfalls with SDIO in 4 bit mode?