ESP32-S3 SPI SD Card Won't Initialize (All Pins & Wiring Verified)

Other Hardware General Electronics
1

Hi everyone,

I'm using an ESP32-S3 dev board and trying to connect a standard microSD card via SPI. I'm not using SDMMC, only SPI mode.

Hardware setup:

  • CS: GPIO13
  • MOSI: GPIO20
  • MISO: GPIO19
  • SCK: GPIO18
  • All lines have 4.7k pull-up resistors to 3.3V
  • SD card is formatted with SD Card Formatter (tested with 2GB FAT and 16GB FAT32)
  • Supply voltage is steady 3.34V
  • No TFT or other devices sharing these pins

What happens:

  • I consistently get SD Card Mount Failed or Card initialization failed
  • The SPI test returns 0xFF responses (at least showing MISO is reading)
  • Tried both the Arduino SD library and SdFat with custom SPI instances
  • I tested with multiple SD cards, verified wiring multiple times, tried with different CS and SCK pins
  • ESP32 works fine otherwise, just SD via SPI won’t initialize

Has anyone had success with ESP32-S3 and SD over SPI mode?

Any help, working pin configurations or example code is highly appreciated. Thanks!

"Problema con SD via SPI su ESP32-S3 – Inizializzazione fallita nonostante connessioni corrette"
SD Library Issue
2

Please read the pinned post re 'How to get the most from the forum'

1 Like
3

Try without them.

4

Which SD card module. There are 3.3volt and 5volt variants.
I2C needs pull up resistors, SPI not.
Leo..

5

Why not post the code you are using ?

6

Tank for your answer, the resistors are integrated in a board ILI9448 tft 4"

7

Sorry, you said in the first post;

"No TFT or other devices sharing these pins"

?

8

The 4" tft module have only four SPI indipendent pins. Two SD cards, one is a micro sd 16GB with adapter and the secon is a 2GB Thoshiba.

9 
#include <SPI.h>
#include <SD.h>

#define CS_SD   13
#define MOSI_SD 20
#define MISO_SD 19
#define SCK_SD  18  // also tried 14

SPIClass SPI_SD(VSPI);

void setup() {
  Serial.begin(115200);
  delay(1000);

  Serial.println("========== DEBUG SPI SD ==========");
  Serial.printf("CS: %d\nMOSI: %d\nMISO: %d\nSCK: %d\n", CS_SD, MOSI_SD, MISO_SD, SCK_SD);

  Serial.println(">> Initializing SPI with custom pins...");
  SPI_SD.begin(SCK_SD, MISO_SD, MOSI_SD, CS_SD);

  Serial.println(">> Checking pin states:");
  Serial.printf("MOSI: %d\n", digitalRead(MOSI_SD));
  Serial.printf("MISO: %d\n", digitalRead(MISO_SD));
  Serial.printf("SCK: %d\n",  digitalRead(SCK_SD));
  Serial.printf("CS: %d\n",   digitalRead(CS_SD));

  Serial.println(">> Testing SPI: sending dummy 0xFF commands...");
  for (int i = 0; i < 10; i++) {
    uint8_t response = SPI_SD.transfer(0xFF);
    Serial.printf("SPI response: 0x%02X\n", response);
  }

  Serial.println(">> Attempting SD.begin()...");
  if (!SD.begin(CS_SD, SPI_SD)) {
    Serial.println("!!! SD initialization failed (check wiring and card)");
  } else {
    Serial.println("SD card successfully initialized!");
  }
}

void loop() {
  delay(5000);
}
10

Now is all ok using this code `#include <SPI.h>
#include <SD.h>

#define SD_CS 13
#define SD_SCK 18
#define SD_MOSI 19
#define SD_MISO 20

SPIClass sdSPI(FSPI); // Usa FSPI per SD (corrisponde alla SPI principale su molti S3)

void setup() {
Serial.begin(115200);
delay(1000);

// Inizializza SPI con i tuoi pin
sdSPI.begin(SD_SCK, SD_MISO, SD_MOSI, SD_CS);

// Inizializza la SD con SPI personalizzata
if (!SD.begin(SD_CS, sdSPI)) {
Serial.println("SD card initialization failed!");
return;
}

Serial.println("SD card initialized successfully!");
File file = SD.open("/test.txt", FILE_WRITE);
if (file) {
file.println("Ciao dal futuro!");
file.close();
Serial.println("Scrittura completata.");
} else {
Serial.println("Impossibile scrivere sul file.");
}
}

void loop() {}
`

11

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