SD card is always in 'TRANSFER' state.

[ENo.1]

Hi

I'm using STM32F103VGT6 and now days i have a problem in working with SD cards.

I can't use FatFs library.

"HAL_SD_GetCardState" function, always return 'TRANSFER' state.

I try multiple SD cards, clock divider and any many configs.

please help.

thanks

[TDK]

The TRANSFER state is where the card is most of the time. Do you think it should be in a different state?

https://user-images.githubusercontent.com/77482/29501948-45c1c196-85e1-11e7-9bfc-d4817115d5bb.png

[ENo.1]

thanks @TDK​ 

This function (HAL_SD_GetCardState) has multiple output.

For example:

-HAL_SD_CARD_READY

Card state is ready

-HAL_SD_CARD_IDENTIFICATION

Card is in identification state

-HAL_SD_CARD_STANDBY

Card is in standby state

-HAL_SD_CARD_TRANSFER

Card is in transfer state

-HAL_SD_CARD_SENDING

Card is sending an operation

-HAL_SD_CARD_RECEIVING

Card is receiving operation information

'HAL_SD_CARD_READY' state, means SD card is ready for do an operation.

It seems that in most of the time, SD card must in READY state, not TRANSFER state.

in TRANSFER state, i can't read or write from/to SD card. it means SD card is doing an operation and its busy.

[TDK]

> in TRANSFER state, i can't read or write from/to SD card. it means SD card is doing an operation and its busy.

That's simply not true. Most commands, including read/write commands, are initiated when the card is in the transfer state. See the graph that I linked. If you have a copy of the SD standard, there are more details in there. I linked the figure for eMMC, but SD is similar.

[ENo.1]

My written program code is really simple and it has a 'while' loop which controls SD card's state and its compatible with manual's note :

while(HAL_SD_GetCardState(&hsd) == HAL_SD_CARD_TRANSFER);

...

in debug mode, program stopped on this line and never run next line!!!

it seems that this condition not changed and always in TRANSFER mode!

i saw in other's code, that always check this condition, but for me not answered!

[TDK]

I'm still sticking to my story that TRANSFER is the correct state for the card prior to and read/write data commands, as shown in the picture in the first response. It doesn't sound like you believe me, so not sure I can help here.

> i saw in other's code, that always check this condition, but for me not answered!

I can't comment on other people's code that you're even not linking to. There is a lot of crap out there.

[kgai]

poor ENO. You know that the ST employee are very busy just like the SD Card always in transfer mode, So u are ignored. Change 2 another processor like TI or microchip may be a better choice.