ESP32-cam SD card problem with saving data

Other Hardware Storage
1

I am using esp32-cam and would like to save sensor data to SD card. Unfortunately, when I send data command by file.println in void loop, the file is empty or the file only contains data after one pass of the loop.

1 Like
2

Probably a problem with your code that you forgot to post.

3 
#include "SD_MMC.h"
#include "SPI.h"

void setup(){ 
  Serial.begin(115200);    
}

void loop(){
   
     if(!SD_MMC.begin()){
        Serial.println("Failed to mount card");
        return;
    }
 
    File file = SD_MMC.open("/test.txt", FILE_WRITE);
     
    if(!file){
        Serial.println("Opening file failed");
        return;
   }
     
    file.println("Test");
    delay(1000);
    }
4

You are doing this every loop. You only need to do it once... put it in setup();

5

I did it. The same problem file is empty.

6

You need to close the file as well...

    file.close();


#include "SD_MMC.h"
#include "SPI.h"

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

  if (!SD_MMC.begin())
  {
    Serial.println("Failed to mount card");
    return;
  }

  File file = SD_MMC.open("/test.txt", FILE_WRITE);

  if (!file)
  {
    Serial.println("Opening file failed");
    return;
  }

  for (uint8_t x = 0; x < 10; x++)
  {
    file.println("Test");
  }

  file.close();
}


void loop()
{}
7

Your code working, but this code isn't working in void loop. I want measure data sensor.

8

Of course that code will work in loop...

Just remember...

You open the file ONCE.
You write your sensor data... as many times as you want.
You close the file ONCE.

9

Ok, understand now. I'II try. Tkanks for helping.

10

Hi, I too am trying to log data to the sd card on an esp32-cam .. could you share your code that works? It would be extremely helpful to me

11

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