ESP32-CAM AI-Thinker Board Overview: Pinout, OV2640, PSRAM and Limits

#include "esp_camera.h"

// AI-Thinker ESP32-CAM camera pins
#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

#define RED_LED 33   // on-board red LED, active LOW

bool initCamera() {
  camera_config_t config = {};          // zero all fields first
  config.ledc_channel = LEDC_CHANNEL_0;   // LEDC makes the 20 MHz XCLK
  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_sccb_sda = SIOD_GPIO_NUM;
  config.pin_sccb_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;
  config.frame_size   = FRAMESIZE_VGA;     // 640 x 480 for the test
  config.jpeg_quality = 12;
  config.fb_count     = 1;
  config.fb_location  = psramFound() ? CAMERA_FB_IN_PSRAM : CAMERA_FB_IN_DRAM;
  config.grab_mode    = CAMERA_GRAB_LATEST;
  return esp_camera_init(&config) == ESP_OK;
}

void setup() {
  Serial.begin(115200);
  delay(500);
  pinMode(RED_LED, OUTPUT);
  digitalWrite(RED_LED, HIGH);            // LED off (active LOW)

  Serial.printf("Chip: %s rev %d, %d cores\n", ESP.getChipModel(), ESP.getChipRevision(), ESP.getChipCores());
  Serial.printf("Flash size: %u bytes\n", ESP.getFlashChipSize());
  Serial.printf("PSRAM found: %s, size %u bytes\n", psramFound() ? "yes" : "no", ESP.getPsramSize());

  if (!initCamera()) {
    Serial.println("Camera init FAILED - check ribbon cable and board selection");
    return;
  }

  sensor_t *s = esp_camera_sensor_get();
  Serial.printf("Sensor PID: 0x%02X (OV2640 is 0x%02X)\n", s->id.PID, OV2640_PID);

  camera_fb_t *fb = esp_camera_fb_get();  // grab one frame
  if (!fb) {
    Serial.println("Frame capture FAILED");
    return;
  }
  Serial.printf("Test frame: %ux%u, %u bytes JPEG\n", fb->width, fb->height, fb->len);
  esp_camera_fb_return(fb);              // always give the buffer back

  Serial.println("All tests passed");
  for (int i = 0; i < 5; i++) {          // blink red LED as a pass signal
    digitalWrite(RED_LED, LOW);
    delay(200);
    digitalWrite(RED_LED, HIGH);
    delay(200);
  }
}

void loop() {
}