Issue with Sharing SPI Pins for MicroSD and LCD/TFT on ESP32 (Wroom ESP32)

WiFi+Bluetooth module ESP32 D1 mini

1.3 TFT IPS ST7789 240X240

Setup:

  • SPI Pins:
    • SCK: GPIO18
    • MOSI: GPIO23
    • MISO: GPIO19 (used by SD card, not the TFT)
  • TFT:
    • CS: GPIO26
    • DC: GPIO17
    • Backlight: GPIO4
    • SDA/MOSI: GPIO23
    • SCL: GPIO18
    • RES: GPIO16
  • MicroSD:
    • CS: GPIO5
    • SCK: GPIO18
    • MOSI: GPIO23
    • MISO: GPIO19

Problem:

Hello,

  • When the TFT is initialized first, even if the SD card initialization is done afterward in the code, the SD card fails to initialize.
  • When the SD card is initialized first, it works fine, and the TFT works afterward as expected.
#include <TFT_eSPI.h>
#include <SD.h>
#include <SPI.h>

// Create TFT object
TFT_eSPI tft = TFT_eSPI();

// Define pins for TFT and SD card
#define TFT_CS 26    // TFT Chip Select
#define SD_CS 5      // SD Card Chip Select

void setup() {
  // Disable brownout detector
  WRITE_PERI_REG(RTC_CNTL_BROWN_OUT_REG, 0);

  // Initialize Serial Monitor
  Serial.begin(115200);
  vTaskDelay(300); // Short delay for stability

  // Set pin modes and initial states
  pinMode(TFT_CS, OUTPUT);
  digitalWrite(TFT_CS, HIGH); // TFT chip select inactive
  pinMode(SD_CS, OUTPUT);
  digitalWrite(SD_CS, HIGH); // SD card chip select inactive

  // Initialize TFT
  digitalWrite(SD_CS, HIGH); // Ensure SD is not active
  digitalWrite(TFT_CS, LOW); // Activate TFT
  tft.init();
  tft.setRotation(1);
  tft.fillScreen(TFT_BLACK);
  tft.setTextColor(TFT_WHITE, TFT_BLACK);
  tft.setTextSize(2);
  tft.println("TFT Initialized");
  digitalWrite(TFT_CS, HIGH); // Deactivate TFT

  // Initialize SD card
  digitalWrite(TFT_CS, HIGH); // Ensure TFT is not active
  digitalWrite(SD_CS, LOW);   // Activate SD
  if (!SD.begin(SD_CS)) {
    Serial.println("SD Card initialization failed!");
    digitalWrite(SD_CS, HIGH); // Deactivate SD
    return;
  }
  Serial.println("SD Card initialized.");
  digitalWrite(SD_CS, HIGH); // Deactivate SD

  // Test message
  digitalWrite(TFT_CS, LOW); // Activate TFT
  tft.println("SD Card OK");
  digitalWrite(TFT_CS, HIGH); // Deactivate TFT
}

void loop() {
  // Nothing here for now
}

I moved your topic to an appropriate forum category @kareem_aly .

In the future, please take some time to pick the forum category that best suits the subject of your topic. There is an "About the _____ category" topic at the top of each category that explains its purpose.

This is an important part of responsible forum usage, as explained in the "How to get the best out of this forum" guide. The guide contains a lot of other useful information. Please read it.

Thanks in advance for your cooperation.

Okey ty

A few things.

First the ESP32 has 2 SPI busses available to the user. If you have enough pins to switch the SD to HSPI, that would be simpler or better as you like.

Second, Are you sure the SD card actually works properly ? Have you done a full SD-test sketch ?

And eh which esp32 core version are you using ?

ESP32 Core Version: v5.1.4-972-g632e0c2a9f-dirty
yes i have done sd full test

/*
 * pin 1 - not used          |  Micro SD card     |
 * pin 2 - CS (SS)           |                   /
 * pin 3 - DI (MOSI)         |                  |__
 * pin 4 - VDD (3.3V)        |                    |
 * pin 5 - SCK (SCLK)        | 8 7 6 5 4 3 2 1   /
 * pin 6 - VSS (GND)         | ▄ ▄ ▄ ▄ ▄ ▄ ▄ ▄  /
 * pin 7 - DO (MISO)         | ▀ ▀ █ ▀ █ ▀ ▀ ▀ |
 * pin 8 - not used          |_________________|
 *                             ║ ║ ║ ║ ║ ║ ║ ║
 *                     ╔═══════╝ ║ ║ ║ ║ ║ ║ ╚═════════╗
 *                     ║         ║ ║ ║ ║ ║ ╚══════╗    ║
 *                     ║   ╔═════╝ ║ ║ ║ ╚═════╗  ║    ║
 * Connections for     ║   ║   ╔═══╩═║═║═══╗   ║  ║    ║
 * full-sized          ║   ║   ║   ╔═╝ ║   ║   ║  ║    ║
 * SD card             ║   ║   ║   ║   ║   ║   ║  ║    ║
 * Pin name         |  -  DO  VSS SCK VDD VSS DI CS    -  |
 * SD pin number    |  8   7   6   5   4   3   2   1   9 /
 *                  |                                  █/
 *                  |__▍___▊___█___█___█___█___█___█___/
 *
 * Note:  The SPI pins can be manually configured by using `SPI.begin(sck, miso, mosi, cs).`
 *        Alternatively, you can change the CS pin and use the other default settings by using `SD.begin(cs)`.
 *
 * +--------------+---------+-------+----------+----------+----------+----------+----------+
 * | SPI Pin Name | ESP8266 | ESP32 | ESP32‑S2 | ESP32‑S3 | ESP32‑C3 | ESP32‑C6 | ESP32‑H2 |
 * +==============+=========+=======+==========+==========+==========+==========+==========+
 * | CS (SS)      | GPIO15  | GPIO5 | GPIO34   | GPIO10   | GPIO7    | GPIO18   | GPIO0    |
 * +--------------+---------+-------+----------+----------+----------+----------+----------+
 * | DI (MOSI)    | GPIO13  | GPIO23| GPIO35   | GPIO11   | GPIO6    | GPIO19   | GPIO25   |
 * +--------------+---------+-------+----------+----------+----------+----------+----------+
 * | DO (MISO)    | GPIO12  | GPIO19| GPIO37   | GPIO13   | GPIO5    | GPIO20   | GPIO11   |
 * +--------------+---------+-------+----------+----------+----------+----------+----------+
 * | SCK (SCLK)   | GPIO14  | GPIO18| GPIO36   | GPIO12   | GPIO4    | GPIO21   | GPIO10   |
 * +--------------+---------+-------+----------+----------+----------+----------+----------+
 *
 * For more info see file README.md in this library or on URL:
 * https://github.com/espressif/arduino-esp32/tree/master/libraries/SD
 */

#include "FS.h"
#include "SD.h"
#include "SPI.h"



#define REASSIGN_PINS
int sck = 18;
int miso = 19;
int mosi = 23;
int cs = 5;


void listDir(fs::FS &fs, const char *dirname, uint8_t levels) {
  Serial.printf("Listing directory: %s\n", dirname);

  File root = fs.open(dirname);
  if (!root) {
    Serial.println("Failed to open directory");
    return;
  }
  if (!root.isDirectory()) {
    Serial.println("Not a directory");
    return;
  }

  File file = root.openNextFile();
  while (file) {
    if (file.isDirectory()) {
      Serial.print("  DIR : ");
      Serial.println(file.name());
      if (levels) {
        listDir(fs, file.path(), levels - 1);
      }
    } else {
      Serial.print("  FILE: ");
      Serial.print(file.name());
      Serial.print("  SIZE: ");
      Serial.println(file.size());
    }
    file = root.openNextFile();
  }
}

void createDir(fs::FS &fs, const char *path) {
  Serial.printf("Creating Dir: %s\n", path);
  if (fs.mkdir(path)) {
    Serial.println("Dir created");
  } else {
    Serial.println("mkdir failed");
  }
}

void removeDir(fs::FS &fs, const char *path) {
  Serial.printf("Removing Dir: %s\n", path);
  if (fs.rmdir(path)) {
    Serial.println("Dir removed");
  } else {
    Serial.println("rmdir failed");
  }
}

void readFile(fs::FS &fs, const char *path) {
  Serial.printf("Reading file: %s\n", path);

  File file = fs.open(path);
  if (!file) {
    Serial.println("Failed to open file for reading");
    return;
  }

  Serial.print("Read from file: ");
  while (file.available()) {
    Serial.write(file.read());
  }
  file.close();
}

void writeFile(fs::FS &fs, const char *path, const char *message) {
  Serial.printf("Writing file: %s\n", path);

  File file = fs.open(path, FILE_WRITE);
  if (!file) {
    Serial.println("Failed to open file for writing");
    return;
  }
  if (file.print(message)) {
    Serial.println("File written");
  } else {
    Serial.println("Write failed");
  }
  file.close();
}

void appendFile(fs::FS &fs, const char *path, const char *message) {
  Serial.printf("Appending to file: %s\n", path);

  File file = fs.open(path, FILE_APPEND);
  if (!file) {
    Serial.println("Failed to open file for appending");
    return;
  }
  if (file.print(message)) {
    Serial.println("Message appended");
  } else {
    Serial.println("Append failed");
  }
  file.close();
}

void renameFile(fs::FS &fs, const char *path1, const char *path2) {
  Serial.printf("Renaming file %s to %s\n", path1, path2);
  if (fs.rename(path1, path2)) {
    Serial.println("File renamed");
  } else {
    Serial.println("Rename failed");
  }
}

void deleteFile(fs::FS &fs, const char *path) {
  Serial.printf("Deleting file: %s\n", path);
  if (fs.remove(path)) {
    Serial.println("File deleted");
  } else {
    Serial.println("Delete failed");
  }
}

void testFileIO(fs::FS &fs, const char *path) {
  File file = fs.open(path);
  static uint8_t buf[512];
  size_t len = 0;
  uint32_t start = millis();
  uint32_t end = start;
  if (file) {
    len = file.size();
    size_t flen = len;
    start = millis();
    while (len) {
      size_t toRead = len;
      if (toRead > 512) {
        toRead = 512;
      }
      file.read(buf, toRead);
      len -= toRead;
    }
    end = millis() - start;
    Serial.printf("%u bytes read for %lu ms\n", flen, end);
    file.close();
  } else {
    Serial.println("Failed to open file for reading");
  }

  file = fs.open(path, FILE_WRITE);
  if (!file) {
    Serial.println("Failed to open file for writing");
    return;
  }

  size_t i;
  start = millis();
  for (i = 0; i < 2048; i++) {
    file.write(buf, 512);
  }
  end = millis() - start;
  Serial.printf("%u bytes written for %lu ms\n", 2048 * 512, end);
  file.close();
}

void setup() {
  Serial.begin(115200);
  while (!Serial) {
    delay(10);
  }

#ifdef REASSIGN_PINS
  SPI.begin(sck, miso, mosi, cs);
  if (!SD.begin(cs)) {
#else
  if (!SD.begin()) {
#endif
    Serial.println("Card Mount Failed");
    return;
  }
  uint8_t cardType = SD.cardType();

  if (cardType == CARD_NONE) {
    Serial.println("No SD card attached");
    return;
  }

  Serial.print("SD 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.cardSize() / (1024 * 1024);
  Serial.printf("SD Card Size: %lluMB\n", cardSize);

  listDir(SD, "/", 0);
  createDir(SD, "/mydir");
  listDir(SD, "/", 0);
  removeDir(SD, "/mydir");
  listDir(SD, "/", 2);
  writeFile(SD, "/hello.txt", "Hello ");
  appendFile(SD, "/hello.txt", "World!\n");
  readFile(SD, "/hello.txt");
  deleteFile(SD, "/foo.txt");
  renameFile(SD, "/hello.txt", "/foo.txt");
  readFile(SD, "/foo.txt");
  testFileIO(SD, "/test.txt");
  Serial.printf("Total space: %lluMB\n", SD.totalBytes() / (1024 * 1024));
  Serial.printf("Used space: %lluMB\n", SD.usedBytes() / (1024 * 1024));
}

void loop() {}

here is the output
Deleting file: /foo.txt

File deleted

Renaming file /hello.txt to /foo.txt

File renamed

Reading file: /foo.txt

Read from file: Hello World!

1048576 bytes read for 2479 ms

1048576 bytes written for 3021 ms

Total space: 7616MB

Used space: 1MB

i am still new at embedded systems so i dont know where hspi
i watched many videos but not the same esp32

Well on an ESP32 you can user define the SPI pins.
i use a pointer method to use it

SPIClass * hspi = NULL;

void setup() {
  if (hspi == NULL) {
    hspi = new SPIClass(HSPI);
  }
  hspi->begin(HSPI_SCK, HSPI_MISO, HSPI_MOSI, SD_CS);
  hspi->setFrequency(SPI_FRQ);
}

You can define any pins though they do have to be Output capable (Looking at the pinout i think they all are) Note the using of the SPI thru it's pointer. (-> instead of . )

ty it works ty again and sry for the delay bcs i am working two jobs ty