stevstrong

I have the same problem with the bluepill board. Flashed with STLink utility the latest generic pc13 bin file. Then pressed reset, nothing happened. When unplug ->replug the USB cable,...

Thanks for the clarification. If I use `SdioConfig config`, then `HAS_SDIO_CLASS` has to be set to 1 in the configuration file, right?

Thanks for the info, I have already written an [SDIO driver for my (Libmaple) core](https://github.com/stevstrong/Arduino_STM32/tree/master/STM32F4/libraries/SDIO) based on [my forked SdFat V1](https://github.com/stevstrong/SdFat). I have observed in V2 the **block** read/write functions...

Ok, I can compile an example using only `sd.begin(SdioConfig(DMA_SDIO))`, but I think there is still something I do not understand because is seems that also the SPI library is linked...

Thank your for the hint, indeed, the driver was missing, I compiled for STM32F103 chip which did not have any enabled SDIO driver in my core. I changed the config...

I come back to this because I have observed an undesired effect: both SDIO and SPI libraries are linked to the project even if I use only SDIO. Can you...

Sorry to bother regarding this, but the warning message is generated again even for STM32F407 if I set `HAS_SDIO_CLASS` non-zero and use the SPI configuration in begin() instead of SDIO...

For F4x family it is suggested to use a larger buffer, e.g. 8kB.

I suggested 8kB because it was tested with the Libmaple (Roger Clark's) core using DMA.

There is no restriction to use 4 bytes, the DMA works on byte level. And the non-DMA SPI driver is also highly optimized so it does not (always) have gaps...