SD mount not working reliable

[atsteich]

Hardware:

Board: Adafruit HUZZAH32 Feather + SD/RTC Shield
Core Installation/update date: 05/Nov/2018
IDE name: Platform.io
Computer OS: Windows 10 and Ubuntu

Description:

There are problems mounting micro SD cards after rebooting.

The first time after inserting a micro SD card (e.g. Sundisk Ultra) and rebooting the chip, everything works fine. Leaving the card in the holder and rebooting again i get in ~50% of all attempts the error:
[E][sd_diskio.cpp:739] sdcard_mount(): f_mount failed 0x(3)

After reinserting the card (or removing power supply of the sd card holder) everything works fine again, but only for the first reboot.

I found some kind of 'workaround'. If you call SD.begin(CS) in a loop until it returns true, u will be able to mount the card, sometimes after 2-3 attempts, sometimes after 10.

I have tried with at least 3 different chips, multiple different SD card holder (some feather shields, an other micro SD holder, and an SD holder) and multiple different SD cards. -> same result for all of them.

Sketch:

#include <Arduino.h>
#include <SD.h>

void setup(){
  Serial.begin(115200);
    delay(200);
    while(! SD.begin(33)){
    }
    Serial.println("SD OK");
}

void loop(){
    File file = SD.open("/testfile.txt", FILE_APPEND);
    file.println("printAnythingHerer");
    file.close();
}

Debug Messages:

rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2

load:0x3fff0018,len:4
load:0x3fff001c,len:952
load:0x40078000,len:6084
load:0x40080000,len:7944
entry 0x40080310
[E][sd_diskio.cpp:739] sdcard_mount(): f_mount failed 0x(3)
[E][sd_diskio.cpp:739] sdcard_mount(): f_mount failed 0x(3)
[E][sd_diskio.cpp:739] sdcard_mount(): f_mount failed 0x(3)
[E][sd_diskio.cpp:739] sdcard_mount(): f_mount failed 0x(3)
[E][sd_diskio.cpp:739] sdcard_mount(): f_mount failed 0x(3)
[E][sd_diskio.cpp:739] sdcard_mount(): f_mount failed 0x(3)
[E][sd_diskio.cpp:739] sdcard_mount(): f_mount failed 0x(3)
[E][sd_diskio.cpp:739] sdcard_mount(): f_mount failed 0x(3)
[E][sd_diskio.cpp:739] sdcard_mount(): f_mount failed 0x(3)
SD OK

[imcort]

I have the same problem.

[imcort]

I've tried to put the SD.begin(CS) into a loop and added some delays, but it doesn't have any effect.

[atsteich]

@imcord Is it working after reinserting the card?

[imcort]

@atsteich yes, I reinserted the card and reconnect the cable.
My SPI bus also connect a lcd screen and the screen works fine, but the sd card doesn't work even if I remove all of the wires and lcd, only plug the sd card.

[imcort]

@atsteich Are you using a tf-to-sd adapter? I found that when I pinch the two sides of the adapter, then the program runs correctly.

[atsteich]

I have been trying with both, tf-to-sd adapter, and with the sd/rtc feather wing from adafruit (https://www.adafruit.com/product/2922) same result... I'll try pinching the adapter later, but I do not think that this will solve the problem, since it always works after calling SD.begin(CS) multiple times.
I think this could be some kind of buffer problem that happens when the esp is rebooting while SPI transmission is active... But to be honest, I have no idea about SPI protocoll, I will dig into as soon I find some time... I also will try adding a capacitor to the power supply of the sd card holder, maybe there are some power problems in my hardware... Although I don't think it is a hardware problem, since i have tried multiple different chips, and it works fine as soon as I reinsert the card.

[atsteich]

Update: So far I can say that this is ONLY happening if the esp is rebooting while SPI transmission is active. The "workaround (calling SD.begin(cs) until it returns true) has never failed until now, but sometimes it takes up to ~20 times. I have tried pulling cs HIGH manually before calling SD.begin(), didn't change anything. The only way to get it work every time (at least until now) is disconnecting power line to the sd card holder, or removing and reinserting the micro SD card.

[me-no-dev]

The cause of this is that the SD card is not just some dummy SPI device but it has memory, cpu and whatnot inside. When you break the connection in the middle of a transfer, you are leaving the card in weird state (waiting for more data or specific command). That is why pulling the card works. It's in effect a power cycle for it.

[luandro]

I'm having exactly this same problem.

Removing and inserting the card works somt times and pinching two sides of the adapter also helps some times. But it's getting harder and harder for it to work.

Has there been any updates on this? Is it really a hardware problem with the card adapter?

[hicham-vv]

i have the same issue here