eMMC driver

[marchingband]

Board

ESP32-s3

Device Description

DevKitC-1

Hardware Configuration

I have a custom PCB with eMMC attached as follows

#define EMMC_CLK     GPIO_NUM_16
#define EMMC_CMD    GPIO_NUM_15
#define EMMC_DATA0 GPIO_NUM_4
#define EMMC_DATA1 GPIO_NUM_5
#define EMMC_DATA2 GPIO_NUM_6
#define EMMC_DATA3 GPIO_NUM_7

Version

v2.0.5

IDE Name

Arduino IDE

Operating System

macOS 10.15

Flash frequency

80Mhz

PSRAM enabled

no

Upload speed

115200

Description

In this issue: espressif/esp-idf#8257
It seems there was a patch to esp-idf 4.4 which fixes some issues with the eMMC driver timing.
Has this patch been applied to ESP32-Arduino ?
Thanks!

Sketch

#include "Arduino.h"
#include "FS.h"
#include "driver/sdmmc_types.h"
#include "sd_defines.h"
#include "vfs_api.h"

#include <dirent.h>
#include "esp_vfs_fat.h"
#include "driver/sdmmc_host.h"
#include "driver/sdmmc_defs.h"
#include "sdmmc_cmd.h"
#include "soc/sdmmc_pins.h"
#include "ff.h"
#include "USB.h"

#define EMMC_CLK GPIO_NUM_16
#define EMMC_CMD GPIO_NUM_15
#define EMMC_DATA0 GPIO_NUM_4
#define EMMC_DATA1 GPIO_NUM_5
#define EMMC_DATA2 GPIO_NUM_6
#define EMMC_DATA3 GPIO_NUM_7

sdmmc_card_t *card;
sdmmc_host_t host = SDMMC_HOST_DEFAULT();
  
void init_emmc(){
//    Serial.begin(115200);
   // host.max_freq_khz = SDMMC_FREQ_HIGHSPEED;
   host.max_freq_khz = SDMMC_FREQ_DEFAULT;
//   host.flags = SDMMC_HOST_FLAG_4BIT;
   host.flags = SDMMC_HOST_FLAG_1BIT;
   host.flags &= ~SDMMC_HOST_FLAG_DDR;

   sdmmc_slot_config_t slot_config = SDMMC_SLOT_CONFIG_DEFAULT();
   slot_config.width = 1;
   slot_config.clk = EMMC_CLK;
   slot_config.cmd = EMMC_CMD;
   slot_config.d0 = EMMC_DATA0;
//   slot_config.d1 = EMMC_DATA1;
//   slot_config.d2 = EMMC_DATA2;
//   slot_config.d3 = EMMC_DATA3;

   sdmmc_host_init_slot(SDMMC_HOST_SLOT_1, &slot_config);
   gpio_reset_pin(EMMC_CLK);
   gpio_reset_pin(EMMC_CMD);
   gpio_reset_pin(EMMC_DATA0);
   gpio_reset_pin(EMMC_DATA1);
   gpio_reset_pin(EMMC_DATA2);
   gpio_reset_pin(EMMC_DATA3);
   gpio_pullup_en(EMMC_CLK);
   gpio_pulldown_dis(EMMC_CLK);
   gpio_pullup_en(EMMC_CMD);
   gpio_pulldown_dis(EMMC_CMD);
   gpio_pullup_en(EMMC_DATA0);
   gpio_pulldown_dis(EMMC_DATA0);
   gpio_pullup_en(EMMC_DATA1);
   gpio_pulldown_dis(EMMC_DATA1);
   gpio_pullup_en(EMMC_DATA2);
   gpio_pulldown_dis(EMMC_DATA2);
   gpio_pullup_en(EMMC_DATA3);
   gpio_pulldown_dis(EMMC_DATA3);

//    puts("Initialize HOST and SLOT");

   esp_vfs_fat_sdmmc_mount_config_t mount_config = {
       .format_if_mount_failed = true,
       .max_files = 5,
   };
   
   esp_err_t ret = esp_vfs_fat_sdmmc_mount("/root", &host, &slot_config, &mount_config, &card);
   ESP_ERROR_CHECK(ret);
}

void setup(){
  Serial.begin();
  Serial.setDebugOutput(true);
  USB.begin();
}

int inited = 0;

void loop(){
    Serial.println("run");
    log_i("debug");
    vTaskDelay(1000);
    if(Serial.available()){
        if(inited == 0){
            log_i("init emmc");
            inited = 1;
            init_emmc();
        }
    }
}

Debug Message

ESP_ERROR_CHECK failed: esp_err_t 0x109 (ESP_ERR_INVALID_CRC) at 0x4037a43c

Other Steps to Reproduce

No response

I have checked existing issues, online documentation and the Troubleshooting Guide

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[lbernstone]

That patch was merged before v2.0.5. However, your issue has a different error, which seems more like it is either noise on the line or truly an invalid crc.
Here's where it is thrown in the source code: https://github.com/espressif/esp-idf/blob/master/components/driver/sdmmc_transaction.c#L341

[marchingband]

Ok thank you @lbernstone
What would an invalid CRC indicate other then noise? Perhaps a faulty eMMC chip?

[me-no-dev]

@marchingband why not use the Arduino API for SDMMC?

BTW you are calling sdmmc_host_init_slot(SDMMC_HOST_SLOT_1, &slot_config); and after that you are changing the GPIOs, which would most probably put them in a state that is not what the driver expects.

[igrr]

The patch attached in espressif/esp-idf#8257 hasn't been merged in IDF yet, so very likely SDMMC driver (neither IDF sdmmc_* nor Arduino SDMMC) will work for eMMC on ESP32-S3 yet. Sorry about that, we will try to prioritize that task and merge it into the next v4.4.x release.

[marchingband]

@me-no-dev thanks, I have switched the order, but the error persists.
@igrr @lbernstone
let me summarize because this is a little confusing, can you confirm this is correct?

ESP32-Arduino 2.0.5 using SDMMC class API -> eMMC works
ESP32-Arduino 2.0.5 using idf API -> eMMC works
ESP-IDF 4.x with patch -> eMMC works
ESP-IDF 4.x without patch -> eMMC does not work

Can it be confirmed that it works with Arduino on hardware? I have not seen an example, and there are no example sketches, blog posts, or any mention online of anything, other then the GitHub issue i linked. Has anyone actually succeeded with Arduino using an eMMC chip? I have the eMMC chip KLM4G1FETE-B041

[igrr]

ESP-IDF 4.x with patch -> eMMC works
ESP-IDF 4.x without patch -> eMMC does not work

This sounds correct.

ESP32-Arduino 2.0.5 using SDMMC class API -> eMMC works
ESP32-Arduino 2.0.5 using idf API -> eMMC works

Neither of the APIs works for me in Arduino core 2.0.5 and an eMMC chip.

(I wouldn't expect it to work, given that the above mentioned patch has not been merged into the esp-idf.)

[marchingband]

Ok thank you so so much @igrr that saves me a lot of tinkering. I will work with a patched version of 4.x for now.

@me-no-dev @lbernstone so am I correct that we will have to wait for ESP-Arduino v2.0.6 for eMMC support?

[marchingband]

I can confirm that with esp-idf 4.4 and the patch applied, the above code works as intended on my PCB.
Both 1 and 4 line work, both SDMMC_FREQ_DEFAULT and SDMMC_FREQ_HIGHSPEED work.
Thanks again @igrr :)

here is the adapted code for esp-idf for clarity:

#include <string.h>
#include <sys/unistd.h>
#include <sys/stat.h>
#include "esp_vfs_fat.h"
#include "sdmmc_cmd.h"
#include "driver/sdmmc_host.h"

static const char *TAG = "sdmmc";

#define EMMC_CLK GPIO_NUM_18
#define EMMC_CMD GPIO_NUM_17
#define EMMC_DATA0 GPIO_NUM_4
#define EMMC_DATA1 GPIO_NUM_5
#define EMMC_DATA2 GPIO_NUM_6
#define EMMC_DATA3 GPIO_NUM_7

sdmmc_card_t *card;

void app_main(void)
{
    sdmmc_host_t host = SDMMC_HOST_DEFAULT();

    // host.max_freq_khz = SDMMC_FREQ_DEFAULT;
    host.max_freq_khz = SDMMC_FREQ_HIGHSPEED;
    // host.flags = SDMMC_HOST_FLAG_1BIT;
    host.flags = SDMMC_HOST_FLAG_4BIT;
    host.flags &= ~SDMMC_HOST_FLAG_DDR;

    sdmmc_slot_config_t slot_config = SDMMC_SLOT_CONFIG_DEFAULT();
    slot_config.width = 4;
    slot_config.clk = EMMC_CLK;
    slot_config.cmd = EMMC_CMD;
    slot_config.d0 = EMMC_DATA0;
    slot_config.d1 = EMMC_DATA1;
    slot_config.d2 = EMMC_DATA2;
    slot_config.d3 = EMMC_DATA3;

    gpio_pullup_en(EMMC_CLK);
    gpio_pulldown_dis(EMMC_CLK);
    gpio_pullup_en(EMMC_CMD);
    gpio_pulldown_dis(EMMC_CMD);
    gpio_pullup_en(EMMC_DATA0);
    gpio_pulldown_dis(EMMC_DATA0);
    gpio_pullup_en(EMMC_DATA1);
    gpio_pulldown_dis(EMMC_DATA1);
    gpio_pullup_en(EMMC_DATA2);
    gpio_pulldown_dis(EMMC_DATA2);
    gpio_pullup_en(EMMC_DATA3);
    gpio_pulldown_dis(EMMC_DATA3);

    sdmmc_host_init_slot(SDMMC_HOST_SLOT_1, &slot_config);

    esp_vfs_fat_sdmmc_mount_config_t mount_config = {
        .format_if_mount_failed = true,
        .max_files = 5,
    };
   
    esp_err_t ret = esp_vfs_fat_sdmmc_mount("/root", &host, &slot_config, &mount_config, &card);
    ESP_ERROR_CHECK(ret);

    while(1)
    {
        ESP_LOGI(TAG, "run");
        vTaskDelay(1000);
    }
    vTaskDelete(NULL);
}

[me-no-dev]

am I correct that we will have to wait for ESP-Arduino v2.0.6 for eMMC support?

That depends on when the patch will be released in the v4.4 branch of ESP-IDF. 2.0.6 will be on IDF 4.4.3

[marchingband]

@me-no-dev ok cool thanks. Can we leave this issue open for now then? Just thinking it might help others in my position, and it would be great to get a ping when it is merged into Arduino.