ESP32-CAM (AI-Thinker)

01Quick Facts

• Board profile AI-Thinker ESP32-CAM
• Camera OV2640
• Programming FTDI serial adapter
• Boot mode IO0 to GND for upload only
• Power Stable 5 V supply
• Library esp_camera.h

How It Works

02Technical Specifications

Arduino library: Arduino ESP32 core esp_camera.h camera driver

03Pinout

• 5V Power input Stable 5 V supply Use enough current headroom for Wi-Fi and camera capture.
• GND Ground FTDI GND and supply GND All power and serial connections share ground.
• U0R / RX0 UART receive FTDI TX Cross TX from the adapter to RX on the board.
• U0T / TX0 UART transmit FTDI RX Cross RX from the adapter to TX on the board.
• IO0 Boot strap GND only during upload Disconnect from GND after flashing so the sketch runs.
• PWDN Camera power-down GPIO32 AI-Thinker camera control pin.
• RESET Camera reset -1 / not connected The AI-Thinker profile leaves camera reset unconnected.
• XCLK Camera clock GPIO0 Part of the fixed camera map; avoid extra loads.
• SIOD Camera I2C data GPIO26 OV2640 control bus SDA.
• SIOC Camera I2C clock GPIO27 OV2640 control bus SCL.
• VSYNC Camera sync GPIO25 Fixed AI-Thinker sync pin.
• HREF Camera sync GPIO23 Fixed AI-Thinker sync pin.
• PCLK Camera pixel clock GPIO22 Fixed AI-Thinker pixel clock.
• Y9 Camera data GPIO35 Fixed OV2640 data line.
• Y8 Camera data GPIO34 Fixed OV2640 data line.
• Y7 Camera data GPIO39 Fixed OV2640 data line.
• Y6 Camera data GPIO36 Fixed OV2640 data line.
• Y5 Camera data GPIO21 Fixed OV2640 data line.
• Y4 Camera data GPIO19 Fixed OV2640 data line.
• Y3 Camera data GPIO18 Fixed OV2640 data line.
• Y2 Camera data GPIO5 Fixed OV2640 data line.
• Flash LED Illumination/status GPIO4 on common AI-Thinker boards Confirm clone-board wiring before relying on this LED.

04Wiring Diagram

Programming mode and normal run mode use the same 5 V, GND, and crossed TX/RX wiring. The only difference is IO0: connect IO0 to GND while uploading, then disconnect IO0 from GND and reset the board to run the sketch. Use an adapter with 3.3 V UART logic. A 5 V power output label does not establish its TX voltage. Use one board supply and common ground; do not join independent power outputs.

1. 1

   Unplug the 5 V supply and USB-to-serial adapter before rewiring.

2. 2

   Connect adapter GND to ESP32-CAM GND.

3. 3

   Connect a stable 5 V supply to ESP32-CAM 5V.

4. 4

   Connect adapter TX to ESP32-CAM U0R/RX0.

5. 5

   Connect adapter RX to ESP32-CAM U0T/TX0.

6. 6

   For upload only, connect IO0 to GND and reset the board.

7. 7

   After upload, remove the IO0-to-GND jumper and reset the board for normal sketch execution.

05Code Examples

Arduino-ESP32 3.x: select AI Thinker ESP32-CAM with OV2640 and the fixed pin map below. The bundled esp_camera.h driver is used; no separate camera library or server is required. This sketch captures JPEG frames and reports their sizes over Serial, not a video stream.

#include <Arduino.h>
#include "esp_camera.h"

#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 setup() {
  Serial.begin(115200);

  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_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 = psramFound() ? FRAMESIZE_VGA : FRAMESIZE_QVGA;
  config.jpeg_quality = 12;
  config.fb_count = psramFound() ? 2 : 1;
  config.fb_location = psramFound() ? CAMERA_FB_IN_PSRAM : CAMERA_FB_IN_DRAM;
  config.grab_mode = CAMERA_GRAB_WHEN_EMPTY;

  esp_err_t err = esp_camera_init(&config);
  if (err != ESP_OK) {
    Serial.printf("Camera init failed: 0x%x\n", err);
    Serial.println("Check AI-Thinker board profile, 5 V power, ribbon cable, and PSRAM/frame settings.");
    while (true) delay(1000);
  }

  Serial.println("ESP32-CAM initialized with AI-Thinker pin map.");
}

void loop() {
  camera_fb_t *frame = esp_camera_fb_get();
  if (!frame) {
    Serial.println("Capture failed. Check power and camera connection.");
  } else {
    Serial.printf("JPEG frame: %u x %u, %u bytes\n",
                  (unsigned)frame->width, (unsigned)frame->height, (unsigned)frame->len);
    esp_camera_fb_return(frame);
  }
  delay(1000);
}