Basic Electronics for Beginners: ESP32-CAM Motion Detection Security System

1. Introduction

In security systems, capturing images is useful—but storing them is even more important. In this project, we enhance the ESP32-CAM motion detection system by saving captured images directly to a microSD card.

Whenever motion is detected, the ESP32-CAM captures an image and stores it permanently in the SD card with a unique filename.

This project is ideal for:

Home security systems
Surveillance applications
IoT-based monitoring

2. Components

ESP32-CAM Module
PIR Motion Sensor (HC-SR501)
MicroSD Card (4GB–32GB, FAT32)
FTDI Programmer
Jumper Wires
Breadboard
5V Power Supply (2A recommended)

3. Circuit and Connections

ESP32 CAM Pinout Diagram

Pinout Diagram FTDI Programmer (USB to Serial)

Pinout Diagram of PIR Motion Sensor

🔌 Connections:

💾 SD Card

Insert into ESP32-CAM slot (no wiring needed)

PIR Sensor → ESP32-CAM

VCC → 5V
GND → GND
OUT → GPIO 13

FTDI Programmer → ESP32-CAM (Uploading)

VCC → 5V
GND → GND
TX → U0R
RX → U0T
GPIO0 → GND (for programming mode)

4. Detailed Step-by-Step Circuit Working

PIR sensor detects motion.
Output goes HIGH when motion is present.
ESP32-CAM reads this signal.
Camera captures image using internal camera module.
Image is stored in temporary memory (frame buffer).
Image is then saved to SD card as a .jpg file.
Each image is saved with a unique filename.

5. Code


#include "esp_camera.h"
#include "FS.h"
#include "SD_MMC.h"

#define PIR_PIN 13

void setup() {
  Serial.begin(115200);
  pinMode(PIR_PIN, INPUT);

  if (!SD_MMC.begin()) {
    Serial.println("SD Card Mount Failed");
    return;
  }

  Serial.println("SD Card Initialized");

  camera_config_t config;
  config.ledc_channel = LEDC_CHANNEL_0;
  config.ledc_timer = LEDC_TIMER_0;
  config.pin_d0 = 5;
  config.pin_d1 = 18;
  config.pin_d2 = 19;
  config.pin_d3 = 21;
  config.pin_d4 = 36;
  config.pin_d5 = 39;
  config.pin_d6 = 34;
  config.pin_d7 = 35;
  config.pin_xclk = 0;
  config.pin_pclk = 22;
  config.pin_vsync = 25;
  config.pin_href = 23;
  config.pin_sscb_sda = 26;
  config.pin_sscb_scl = 27;
  config.pin_pwdn = 32;
  config.pin_reset = -1;
  config.xclk_freq_hz = 20000000;
  config.pixel_format = PIXFORMAT_JPEG;

  if (esp_camera_init(&config) != ESP_OK) {
    Serial.println("Camera init failed");
    return;
  }
}

void loop() {
  int motion = digitalRead(PIR_PIN);

  if (motion == HIGH) {
    Serial.println("Motion Detected!");

    camera_fb_t * fb = esp_camera_fb_get();

    if (!fb) {
      Serial.println("Capture failed");
      return;
    }

    String path = "/image_" + String(millis()) + ".jpg";

    File file = SD_MMC.open(path.c_str(), FILE_WRITE);

    if (!file) {
      Serial.println("File open failed");
    } else {
      file.write(fb->buf, fb->len);
      Serial.println("Image saved: " + path);
    }

    file.close();
    esp_camera_fb_return(fb);

    delay(5000); // Avoid multiple captures
  }
}

6. Detailed Step-by-Step Code Working

SD_MMC.begin() initializes SD card

PIR sensor detects motion

esp_camera_fb_get() captures image

millis() generates unique filename

file.write() saves image to SD card

esp_camera_fb_return() clears memory

7. Tips

Use Class 10 SD card for better speed

Always format SD card to FAT32

Use 5V 2A power supply (very important ⚠️)

Adjust PIR sensitivity using onboard potentiometer

Add delay to avoid multiple image captures

8. Uses

Home surveillance system
Office security monitoring
Motion-triggered camera
Evidence recording system

9. Conclusion

This ESP32-CAM SD card-based motion detection system is a powerful and reliable solution for offline security monitoring. It allows continuous image logging without requiring internet connectivity, making it ideal for real-world applications.

Note: Similar Projects

https://simplebasicelectronics.blogspot.com/2026/03/arduino-pir-motion-sensor-alarm.html

https://simplebasicelectronics.blogspot.com/2026/04/esp32-wi-fi-weather-station.html

https://simplebasicelectronics.blogspot.com/2026/03/esp32-cam-face-recognition-system-arduino.html

https://simplebasicelectronics.blogspot.com/2026/03/arduino-keypad-password-door-lock-system.html