ESP32-CAM

What is the ESP32-CAM?

The ESP32-CAM is a tiny Wi-Fi camera board. On 27 × 40.5 mm it packs an ESP32 (dual-core, 240 MHz, Wi-Fi + Bluetooth), 4 MB PSRAM for image buffers, an OV2640 2-megapixel camera, a microSD slot and a bright flash LED.

It is the cheapest way to build an IP camera, a doorbell cam, a time-lapse recorder or a motion-triggered photo trap. The catch is that it has no USB port and only a few spare pins, and it needs a solid 5 V supply. This guide covers all three.

Front: camera, ESP32-S module, microSD, flash LED. Back: AMS1117 regulator, PSRAM, RST button, red LED and the 16 header pins.

Full ESP32-CAM Pinout

The complete ESP32-CAM pinout: all 16 header pins, printed on the back of the board, with each pin's GPIO number, microSD signal, ADC2/touch channel and special role.

The 5V row carries the six microSD/GPIO pins; the 3V3 row carries the serial pins (U0R/U0T), IO0 and IO16.

At a glance, here is what those 16 pins are for:

Most of the ESP32's pins are used by the camera and PSRAM, so only a few are left for you.

Every Pin Explained

OV2640 Camera Pin Map

The camera plugs into a 24-pin FPC connector and uses 16 ESP32 signals: a clock, the SCCB control bus, sync lines and an 8-bit parallel data bus. These are the pins behind CAMERA_MODEL_AI_THINKER.

Control & sync on the left, the 8-bit pixel bus (Y2–Y9) on the right. Four data lines use the ESP32's input-only pins 34–39.

How the Board Fits Together

The ESP32 sits in the middle, streaming camera frames into PSRAM, compressing them to JPEG, then sending them over Wi-Fi or writing them to the SD card.

One ESP32 serves the camera, PSRAM, flash, SD card, LEDs and radio; the AMS1117 regulator supplies 3.3 V.

How to Program the ESP32-CAM with an FTDI Adapter

Because the board has no USB port, you upload through a USB-to-serial (FTDI) adapter. That takes four wires plus one jumper to put the chip into flash mode.

TX → U0R and RX → U0T (they cross). The IO0–GND jumper is only for uploading; remove it to run.

The Easy Way: ESP32-CAM-MB

The ESP32-CAM-MB is a small shield with a micro-USB port and a CH340 USB-serial chip. Plug the ESP32-CAM on top and you get one-cable uploads and a Serial Monitor.

No wires and no IO0 jumper: if the upload stalls at “Connecting…”, hold IO0, tap RST, then release IO0.

Upload Steps & Arduino IDE Settings

Board AI Thinker ESP32-CAM, partition Huge APP (3 MB No OTA), then IO0→GND, RST, upload, remove the jumper, RST.

Which ESP32-CAM Pins Are Free?

This is the most-asked ESP32-CAM question. The answer depends on whether you use the SD card:

No SD card: six free pins. SD in 1-bit mode: GPIO 4, 12, 13. The camera pins are never available.

• Need I2C? Call Wire.begin(14, 15) (or 12/13) when you're not using the SD card. The ESP32 can route I2C to almost any pin; add pull-up resistors.
• Need a button or sensor with SD? Use GPIO13 or GPIO12 with SD in 1-bit mode. Don't pull GPIO12 HIGH at boot.
• Need more pins? Add an I2C I/O expander, or choose an ESP32-S3 camera board.

microSD Card: 4-bit vs 1-bit Mode

The slot uses the ESP32's fast SD_MMC host. In 4-bit mode it takes all six header GPIO; 1-bit mode is a little slower but gives three pins back.

SD_MMC.begin() = 4-bit; SD_MMC.begin("/sdcard", true) = 1-bit (frees GPIO 4, 12, 13 and stops the flash LED flickering).

Power Supply & the Brownout Error

The #1 ESP32-CAM problem isn't code, it's power. The camera and Wi-Fi draw short current peaks, and a weak supply resets the board with “Brownout detector was triggered”.

Give it 5 V at 2 A, short wires, and a 470–1000 µF capacitor across 5V–GND.

Live Video Streaming (CameraWebServer)

The built-in CameraWebServer example turns the board into an IP camera you can watch from any browser on your network.

Control page at http://<IP>/, live stream at :81/stream, and a single photo at /capture.

Resolutions & Image Quality

The OV2640 goes up to UXGA (1600 × 1200), but bigger frames stream more slowly. For smooth video, start at SVGA or VGA.

Set frame_size and jpeg_quality (10–63, lower = better) in camera_config_t.

Using an External Antenna

Weak Wi-Fi and a choppy stream? The module has an IPEX (u.FL) socket, but it only works once you move a tiny 0 Ω link.

Move the 0 Ω resistor from the PCB position to the IPEX position, then plug in a 2.4 GHz antenna.

ESP32-CAM vs ESP32 DevKit vs ESP32-S3

The ESP32-CAM wins on price for a Wi-Fi camera; the ESP32-S3 adds native USB, more pins and AI acceleration.

Code Examples

Every camera sketch starts with the same pin configuration. Save Example 1 as camera_init.h and reuse it.

1. Initialise the camera (AI-Thinker pins)

#include "esp_camera.h"
bool initCamera() {
  camera_config_t c = {};
  c.ledc_channel = LEDC_CHANNEL_0;  c.ledc_timer = LEDC_TIMER_0;
  c.pin_d0 = 5;  c.pin_d1 = 18; c.pin_d2 = 19; c.pin_d3 = 21;   // Y2..Y5
  c.pin_d4 = 36; c.pin_d5 = 39; c.pin_d6 = 34; c.pin_d7 = 35;   // Y6..Y9
  c.pin_xclk = 0;  c.pin_pclk = 22; c.pin_vsync = 25; c.pin_href = 23;
  c.pin_sccb_sda = 26; c.pin_sccb_scl = 27;             // older cores: pin_sscb_*
  c.pin_pwdn = 32; c.pin_reset = -1;
  c.xclk_freq_hz = 20000000;
  c.pixel_format = PIXFORMAT_JPEG;
  c.frame_size   = FRAMESIZE_SVGA;                          // 800 x 600
  c.jpeg_quality = 12;                                     // 10-63, lower = better
  c.fb_count     = 1;
  return esp_camera_init(&c) == ESP_OK;
}

2. Blink the red status LED (GPIO33, active LOW)

void setup() { pinMode(33, OUTPUT); }
void loop() {
  digitalWrite(33, LOW);  delay(500);    // LOW = LED on
  digitalWrite(33, HIGH); delay(500);
}

3. Dim the flash LED with PWM (GPIO4)

void setup() { ledcAttach(4, 5000, 8); }    // core 3.x: pin, Hz, bits
void loop()  { ledcWrite(4, 20); }         // ~8 % brightness, very bright LED!

4. Take one photo and save it to the SD card

#include "SD_MMC.h"
// + initCamera() from Example 1
void setup() {
  Serial.begin(115200);
  if (!initCamera() || !SD_MMC.begin("/sdcard", true)) { Serial.println("init failed"); return; }
  camera_fb_t *fb = esp_camera_fb_get();                 // grab a JPEG frame
  File f = SD_MMC.open("/photo.jpg", FILE_WRITE);
  f.write(fb->buf, fb->len); f.close();
  esp_camera_fb_return(fb);
  Serial.println("saved /photo.jpg");
}
void loop() {}

ESP32-CAM Projects

Three popular builds, from a live Wi-Fi camera to a battery-friendly motion trap.

// File > Examples > ESP32 > Camera > CameraWebServer
#define CAMERA_MODEL_AI_THINKER          // uncomment this model, comment the others
const char *ssid     = "my-ssid";
const char *password = "password";
// Upload, open Serial Monitor @115200, browse to the printed IP address

Project 2 wiring: PIR OUT → GPIO13 (free because SD runs in 1-bit mode), VCC → 5V, GND → GND.

#include "SD_MMC.h"
RTC_DATA_ATTR int n = 0;                              // photo counter survives deep sleep
// + initCamera() from Code Example 1
void setup() {
  if (initCamera() && SD_MMC.begin("/sdcard", true)) {    // 1-bit: frees GPIO13
    camera_fb_t *fb = esp_camera_fb_get();
    File f = SD_MMC.open("/pic" + String(++n) + ".jpg", FILE_WRITE);
    f.write(fb->buf, fb->len); f.close();
    esp_camera_fb_return(fb);
  }
  esp_sleep_enable_ext0_wakeup(GPIO_NUM_13, 1);           // wake when PIR goes HIGH
  esp_deep_sleep_start();
}
void loop() {}

// Project 2 code, but replace the wake-up line with:
esp_sleep_enable_timer_wakeup(60 * 1000000ULL);          // 60 seconds
// Tip: the first frames after power-up can be dark/green — grab and
// discard one or two frames before saving the real photo.

ESP32-CAM Specifications

Typical values for the common AI-Thinker style board; clones vary slightly.

Key Terms — Glossary

Related Topics & Common Searches

Keep building with these Power4All guides:

People Also Search For

esp32-cam pinout · ai thinker esp32-cam pinout · esp32-cam pin diagram · how to program esp32-cam · esp32-cam ftdi wiring · esp32-cam io0 gnd · esp32-cam-mb programmer · esp32-cam ch340 driver · esp32-cam arduino ide setup · esp32-cam camerawebserver · esp32-cam video streaming · esp32-cam ip camera · esp32-cam brownout detector was triggered · esp32-cam failed to connect timed out waiting for packet header · esp32-cam free gpio pins · esp32-cam sd card 1-bit mode · esp32-cam flash led gpio4 · esp32-cam gpio33 led · ov2640 camera pins · camera_model_ai_thinker · esp32-cam external antenna · esp32-cam power supply · esp32-cam pir motion · esp32-cam time-lapse · esp32-cam face detection · esp32-cam resolution · esp32-cam specifications · esp32-cam vs esp32-s3 · esp32-cam projects.

Frequently Asked Questions

Quick answers to the questions people ask most about the ESP32-CAM.

Conclusion & Key Takeaways

The ESP32-CAM is the cheapest route to a Wi-Fi camera. Once you know its three quirks (no USB, few free pins, needs good 5 V power), it's easy to use.

Continue Learning