How can I save an image from the ESP32-CAM to a separate SD card?

Question

For a project, I need to take a picture with the ESP32-CAM, save it to an SD card, and then have the Arduino UNO access the image. I have the ESP32-CAM with OV2640 connected to the ESP32-CAM-MB, which is connected via USB to my laptop.

Currently, I'm using the following code to capture the image and save it to the microSD on the ESP32-CAM.

// Include Required Libraries
 
// Camera libraries
#include "esp_camera.h"
#include "soc/soc.h"
#include "soc/rtc_cntl_reg.h"
#include "driver/rtc_io.h"
 
// MicroSD Libraries
#include "FS.h"
#include "SD_MMC.h"
 
// EEPROM Library
#include "EEPROM.h"
 
// Use 1 byte of EEPROM space
#define EEPROM_SIZE 1
 
// Counter for picture number
unsigned int pictureCount = 0;
 
// Pin definitions for CAMERA_MODEL_AI_THINKER
#define PWDN_GPIO_NUM 32
#define RESET_GPIO_NUM -1
#define XCLK_GPIO_NUM 0
#define SIOD_GPIO_NUM 26
#define SIOC_GPIO_NUM 27
#define Y9_GPIO_NUM 35
#define Y8_GPIO_NUM 34
#define Y7_GPIO_NUM 39
#define Y6_GPIO_NUM 36
#define Y5_GPIO_NUM 21
#define Y4_GPIO_NUM 19
#define Y3_GPIO_NUM 18
#define Y2_GPIO_NUM 5
#define VSYNC_GPIO_NUM 25
#define HREF_GPIO_NUM 23
#define PCLK_GPIO_NUM 22
 
void configESPCamera() {
 // Configure Camera parameters
 
 // Object to store the camera configuration parameters
 camera_config_t config;
 
 config.ledc_channel = LEDC_CHANNEL_0;
 config.ledc_timer = LEDC_TIMER_0;
 config.pin_d0 = Y2_GPIO_NUM;
 config.pin_d1 = Y3_GPIO_NUM;
 config.pin_d2 = Y4_GPIO_NUM;
 config.pin_d3 = Y5_GPIO_NUM;
 config.pin_d4 = Y6_GPIO_NUM;
 config.pin_d5 = Y7_GPIO_NUM;
 config.pin_d6 = Y8_GPIO_NUM;
 config.pin_d7 = Y9_GPIO_NUM;
 config.pin_xclk = XCLK_GPIO_NUM;
 config.pin_pclk = PCLK_GPIO_NUM;
 config.pin_vsync = VSYNC_GPIO_NUM;
 config.pin_href = HREF_GPIO_NUM;
 config.pin_sscb_sda = SIOD_GPIO_NUM;
 config.pin_sscb_scl = SIOC_GPIO_NUM;
 config.pin_pwdn = PWDN_GPIO_NUM;
 config.pin_reset = RESET_GPIO_NUM;
 config.xclk_freq_hz = 20000000;
 config.pixel_format = PIXFORMAT_JPEG; // Choices are YUV422, GRAYSCALE, RGB565, JPEG
 
 // Select lower framesize if the camera doesn't support PSRAM
 if (psramFound()) {
 config.frame_size = FRAMESIZE_XGA; // FRAMESIZE_ + QVGA|CIF|VGA|SVGA|XGA|SXGA|UXGA
 config.jpeg_quality = 10; //10-63 lower number means higher quality
 config.fb_count = 3;
 } else {
 config.frame_size = FRAMESIZE_SVGA;
 config.jpeg_quality = 12;
 config.fb_count = 1;
 }
 
 // Initialize the Camera
 esp_err_t err = esp_camera_init(&config);
 if (err != ESP_OK) {
 Serial.printf("Camera init failed with error 0x%x", err);
 return;
 }
 
 // Camera quality adjustments
 sensor_t * s = esp_camera_sensor_get();
 
 // BRIGHTNESS (-2 to 2)
 s->set_brightness(s, 1);
 // CONTRAST (-2 to 2)
 s->set_contrast(s, 2);
 // SATURATION (-2 to 2)
 s->set_saturation(s, -2);
 // SPECIAL EFFECTS (0 - No Effect, 1 - Negative, 2 - Grayscale, 3 - Red Tint, 4 - Green Tint, 5 - Blue Tint, 6 - Sepia)
 s->set_special_effect(s, 0);
 // WHITE BALANCE (0 = Disable , 1 = Enable)
 s->set_whitebal(s, 1);
 // AWB GAIN (0 = Disable , 1 = Enable)
 s->set_awb_gain(s, 1);
 // WB MODES (0 - Auto, 1 - Sunny, 2 - Cloudy, 3 - Office, 4 - Home)
 s->set_wb_mode(s, 0);
 // EXPOSURE CONTROLS (0 = Disable , 1 = Enable)
 s->set_exposure_ctrl(s, 0);
 // AEC2 (0 = Disable , 1 = Enable)
 s->set_aec2(s, 0);
 // AE LEVELS (-2 to 2)
 s->set_ae_level(s, 0);
 // AEC VALUES (0 to 1200)
 s->set_aec_value(s, 450);
 // GAIN CONTROLS (0 = Disable , 1 = Enable)
 s->set_gain_ctrl(s, 0);
 // AGC GAIN (0 to 30)
 s->set_agc_gain(s, 30);
 // GAIN CEILING (0 to 6)
 s->set_gainceiling(s, (gainceiling_t)0);
 // BPC (0 = Disable , 1 = Enable)
 s->set_bpc(s, 0);
 // WPC (0 = Disable , 1 = Enable)
 s->set_wpc(s, 1);
 // RAW GMA (0 = Disable , 1 = Enable)
 s->set_raw_gma(s, 1);
 // LENC (0 = Disable , 1 = Enable)
 s->set_lenc(s, 1);
 // HORIZ MIRROR (0 = Disable , 1 = Enable)
 s->set_hmirror(s, 0);
 // VERT FLIP (0 = Disable , 1 = Enable)
 s->set_vflip(s, 0);
 // DCW (0 = Disable , 1 = Enable)
 s->set_dcw(s, 1);
 // COLOR BAR PATTERN (0 = Disable , 1 = Enable)
 s->set_colorbar(s, 0);
 
}
 
void initMicroSDCard() {
 // Start the MicroSD card
 
 Serial.println("Mounting MicroSD Card");
 if (!SD_MMC.begin()) {
 Serial.println("MicroSD Card Mount Failed");
 return;
 }
 uint8_t cardType = SD_MMC.cardType();
 if (cardType == CARD_NONE) {
 Serial.println("No MicroSD Card found");
 return;
 }
 
}
 
void takeNewPhoto(String path) {
 // Take Picture with Camera
 
 // Setup frame buffer
 camera_fb_t * fb = esp_camera_fb_get();
 
 if (!fb) {
 Serial.println("Camera capture failed");
 return;
 }
 
 // Save picture to microSD card
 fs::FS &fs = SD_MMC;
 File file = fs.open(path.c_str(), FILE_WRITE);
 if (!file) {
 Serial.println("Failed to open file in write mode");
 }
 else {
 file.write(fb->buf, fb->len); // payload (image), payload length
 Serial.printf("Saved file to path: %s\n", path.c_str());
 }
 // Close the file
 file.close();
 
 // Return the frame buffer back to the driver for reuse
 esp_camera_fb_return(fb);
}
 
void setup() {
 
 // Disable brownout detector
 WRITE_PERI_REG(RTC_CNTL_BROWN_OUT_REG, 0);
 
 // Start Serial Monitor
 Serial.begin(115200);
 
 // Initialize the camera
 Serial.print("Initializing the camera module...");
 configESPCamera();
 Serial.println("Camera OK!");
 
 // Initialize the MicroSD
 Serial.print("Initializing the MicroSD card module... ");
 initMicroSDCard();
 
 // initialize EEPROM with predefined size
 EEPROM.begin(EEPROM_SIZE);
 pictureCount = EEPROM.read(0) + 1;
 
 // Path where new picture will be saved in SD Card
 String path = "/image" + String(pictureCount) + ".jpg";
 Serial.printf("Picture file name: %s\n", path.c_str());
 
 // Take and Save Photo
 takeNewPhoto(path);
 
 // Update EEPROM picture number counter
 EEPROM.write(0, pictureCount);
 EEPROM.commit();
 
 // Bind Wakeup to GPIO13 going LOW
 esp_sleep_enable_ext0_wakeup(GPIO_NUM_13, 0);
 
 Serial.println("Entering sleep mode");
 delay(1000);
 
 // Enter deep sleep mode
 esp_deep_sleep_start();
 
}
void loop() {
 
}

Is there a way to wire the ESP32-CAM so that the Arduino UNO can access the images on the SD card? Or is it possible to wire it to a separate data logging shield with an SD card, that the Arduino UNO could also access?

• tepalia: I think you can find your answer if you follow this tutorial: randomnerdtutorials.com/esp32-cam-take-photo-save-microsd-card This tutorial shows how to take photos with the ESP32-CAM board and save them to a microSD card using Arduino IDE. When you press the ESP32-CAM RESET button, it wakes up, takes a photo and saves it on the microSD card. You can also send pics from ESP32-CAM to telegram: pcbway.com/blog/25/…
• elvishpotato: That's not really what I'm looking for. How can the Arduino UNO access the data saved on the SD card in the ESP32-CAM?