SD.begin() fails after a couple of minutes (only hard reset button let it wroks again)

[matthieuweber]

Hello,

I have a strange issue with SD access :

Each time I want to read / write on SD card (I use SD library) I run this code :

(Since there are concurrent SD access in the web server and main()
I use WebServer class)

HARDWARE:

• ESP32 Wroom (From AZ delivery)
• SD card (different types, about 250 MB)
• TFT_eSPI library running a TJCTM24024 (ILI9341 2.8" SPI TFT touchscreen display)

TFT_MISO 19 // Hardware MISO same as SD
TFT_MOSI 23 // Hardware MOSI same as SD
TFT_SCLK 18 // Hardware CLK same as SD
TFT_CS 32 // TFT CS
TFT_DC 21 // TFT DC
TFT_RST -1 // TFT reset not used
TOUCH_CS 27 // touchpad CS

SD CS is on PIN 5

SOFTWARE :

• Espressif 32 6.4.0

bool SD_busy     // global variable

...

bool init_carte_sd(void)
{
uint8_t test = 0;
uint8_t delais = random(1, 75);
int32_t timeout = millis();

delay(delais);

while (SD_busy == true)  // Wait for  SD card resource to be freed
  {
  yield(); 
  delay(delais);
  if ((millis() - timeout) > 1000) {Serial.print(" TIMEOUT CARTE SD ! "); return false;}
  }  


SD_busy = true;               // Takes SD card resource

delay(100);
while ((!SD.begin(PIN_SD_CS)) && (test++ < 5))  delay(100);
if (test >= 5) return false;  // Fails after  n attempts ?
else           return true;   // OK, SD card initialized !
}

When access is finished I call

SD.end(); 
SD_busy = false;

Things works great but sometimes SD.begin() in my function init_carte_sd() always fails (every call, everywhere).

The only options to get the card working again is :

• Do a power cycle or
• Push reset button or
• Flash a new code or
• Do a software reset

Note that if I remove and reinsert the SD card after, lets say, 10 seconds ...or 1 hour, the card is being detected and working great ONLY if init_carte_sd() never failed since boot. (Doing this remove/insert operation after the first fail occurred wont work).

For me It's not an hardware issue (bug can be reproduced on 3 systems).

But since removing / inserting card works, and a simple reset (keeping power) solve the issue, I believe that there is a initialization issue in SD.begin() when called in multiple threads

SD.end() doesn't "reinitialize totally" the SD card in this case

Any ideas ? Is it a library bug ?

Thanks !

Best,

Matthieu