Utilize Expansion module SD card with Arduino code

[peter_]

Re: Utilize Expansion module SD card with Arduino code

Apologies, I had originally posted in LoPy, but now I think this is really belongs here in Expansion Board. Unfortunately, I think I won't be able to be helped unless someone is willing to fire up Arduino. Please understand I can get the SD card working in MicroPython, that's just not what I'm doing here.

I am working under the assumption that the pins the Expansion Board uses for the SD card are SD: P8: DAT0, P23: SCLK and P4: CMD.

The thread in LoPy4 details how far I've gotten. Spoiler alert: not very.

tl;dr the SD_MMC sketch complains about missing pullups, and that message goes away when I start using internal pullups in my code. Yet I still cannot mount the SD card. I've tried different cards (all Sandisk Ultra - the same used successfully under MicroPython)

More detailed error logs available in the other thread using different methods - native SD, native SD_MMC and SPI

I would be incredibly grateful if someone else was willing to try to mount an SD card using Arduino.

Thanks in advance!

[peter_]

Answering my own question in case anyone else is interested in this.

Accessing the SD card on the Expansion module seems to be exclusively done with the SD_MMC library in arduino. Specifically in 1-bit mode. Internal pullups are required.

This works for me:

 /*
 * Connect the SD card to the following pins:
 *
 * SD Card | ESP32
 *    D2       12
 *    D3       13
 *    CMD      15
 *    VSS      GND
 *    VDD      3.3V
 *    CLK      14
 *    VSS      GND
 *    D0       2  (add 1K pull up after flashing)
 *    D1       4
 */

#include "FS.h"
#include "SD_MMC.h"


void setup(){
    Serial.begin(115200);
    
    pinMode(2, INPUT_PULLUP);
    pinMode(4, INPUT_PULLUP);
    pinMode(15, INPUT_PULLUP);
    
     

    if(!SD_MMC.begin("/sdcard",true)){    // First arg = mount point, Second arg is 1-bit-mode
        Serial.println("Card Mount Failed");
        return;
        
    }
    uint8_t cardType = SD_MMC.cardType();

    if(cardType == CARD_NONE){
        Serial.println("No SD_MMC card attached");
        return;
    }
     Serial.print("SD_MMC Card Type: ");
    if(cardType == CARD_MMC){
        Serial.println("MMC");
    } else if(cardType == CARD_SD){
        Serial.println("SDSC");
    } else if(cardType == CARD_SDHC){
        Serial.println("SDHC");
    } else {
        Serial.println("UNKNOWN");
    }

    uint64_t cardSize = SD_MMC.cardSize() / (1024 * 1024);
    Serial.printf("SD_MMC Card Size: %lluMB\n", cardSize);
    
}
void loop(){

}