Alexandre Pereira

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8 years, 11 months ago.

Where is pin declarations to associate SDFileSystem library to SDCard interface present on F746NG?

Where is pin declarations to associate SDFileSystem library to SDCard interface present on DISCO-F746NG?

Any example?

Question relating to:

Last updated: 20 Apr 2021
The STM32F746G-DISCO discovery board (32F746GDISCOVERY) is a complete demonstration and development platform for STMicroelectronics ARM® Cortex®-M7 core-based STM32F746NGH6 microcontroller.

4 Answers

Thomas Mikhail
8 years, 11 months ago.

Hi, if someone get a answer I will be greatful. Thanks

Sanjiv Bhatia
8 years, 11 months ago.

https://developer.mbed.org/users/mimi3/code/SDFileSystem-neil/file/246743d68d90/main.cpp

SDFileSystem sd( MOSI, MISO, SCLK, CS, "sd",NC,CD_TYPE,12*1000000);  
//SDFileSystem sd(p5, p6, p7, p8, "sd"); // the pinout on the mbed Cool Components workshop board

The SDCARD interface is SPI so standard SPI definitions should apply: MOSI, MISO, SCLK, CS :

https://learn.adafruit.com/adafruit-micro-sd-breakout-board-card-tutorial

https://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus

NSS = Negative (active low) slave select

/media/uploads/juthi/spi_mbed.png

Thanks for your answer Sanjiv ... but your response refer to use external SDCard adapter on arduino interface on card ...

To clarify my question, i am not able to access the internal SDCard interface present in the board and has no easily documentation on this topic.

I am triyng to use maping present on ST documentation ... described bellow:

// From Example ...
// SDFileSystem sd(p5, p6, p7, p12, "sd");  // MOSI, MISO, SCLK, SSEL 
//
// From STM32F746NG DISCO Board (look at http://www.st.com/st-web-ui/static/active/en/resource/technical/document/user_manual/DM00190424.pdf page 24)

// DI = MOSI = PD_2
// DO = MISO = PC_8
// SCLK = CLK = PC_12
// D3 = CS = PC_11
SDFileSystem sd( PD_2, PC_8, PC_12 ,PC_11 , "sd");

But the simple execution of this constructor freeze the board and turn of the screen ...

The problem persists ... :-(

posted by Alexandre Pereira 20 Jan 2016
sabme ua
8 years, 11 months ago.

Maybe, Disco-F746NG does not have a SDIO and its SPI mode, but there is a SD/MMC interface. So , It needs to implement a bridge interface of SD/MMC driver in the SDFileSystem class if you want to use it.

Bill Bellis
8 years, 11 months ago.

I agree with takuya m, it appears that the on-board SD card interface only is wired through the SD/MMC interface. You can see that from the schematics link here: http://www.st.com/web/catalog/tools/FM116/SC959/SS1532/LN1848/PF261641?s_searchtype=partnumber

From the datasheet for the part here: http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00166116.pdf

The pins used do not have a SPI alternate function. The basic operation is similar for SPI vs SD but you need to set up the registers for SD/MMC. There might be some example code out there for this... take a look at some other vendors who have implemented this function on their boards (hint: Embedded Artists for LPC4088).