DIY Power-Saving Surveillance Camera with ESP32-CAM and PIR Sensor

I am going outside the town for a week or so and during that period I wanted to install a surveillance system build with ES32-CAM, PIR sensor and maybe SD-Card to save the picture or video. I build simple video streaming system with ESP32-CAM which steams video on url in real time. But this system is continuously on and power is wasted. I think this is possible and a great way to create a low-power surveillance system!

Here's how I plan implement it:

Concept Overview

The PIR sensor detects motion
When motion is detected, it wakes the ESP32-CAM from deep sleep
The camera captures images/video and saves to SD card
After recording, the system returns to deep sleep

Required Components

ESP32-CAM module
PIR motion sensor (HC-SR501)
MicroSD card (for storage)
Power source (battery or USB)

Basic Implementation Steps

Hardware Connections:
- Connect PIR output to a GPIO pin on ESP32-CAM (e.g., GPIO 13)
- Ensure ESP32-CAM has SD card inserted
Key Code Logic:


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

#define PIR_PIN 13

void setup() {
  pinMode(PIR_PIN, INPUT);
  
  // Initialize camera
  camera_config_t config;
  // ... camera configuration code ...
  esp_err_t err = esp_camera_init(&config);
  
  // Initialize SD card
  if(!SD_MMC.begin()){
    Serial.println("SD Card Mount Failed");
    return;
  }
}

void loop() {
  if(digitalRead(PIR_PIN) == HIGH) {
    // Motion detected - capture and save image
    camera_fb_t *fb = esp_camera_fb_get();
    if(fb) {
      // Save to SD card with timestamp
      String path = "/image" + String(millis()) + ".jpg";
      fs::FS &fs = SD_MMC;
      File file = fs.open(path.c_str(), FILE_WRITE);
      file.write(fb->buf, fb->len);
      file.close();
      esp_camera_fb_return(fb);
    }
    
    // Add delay to prevent multiple triggers
    delay(10000); // 10 seconds between detections
  }
  
  // Optional: Enter deep sleep between checks to save power
  // esp_deep_sleep(1000000); // 1 second sleep
}

Power Saving Enhancements

Deep Sleep Mode:
- Use the PIR sensor to wake the ESP32 from deep sleep
- Configure the PIR output to connect to a wake-up capable GPIO
Optimized Capture:
- Only capture when motion is detected
- Limit capture duration/frequency
- Reduce image resolution/quality when possible
Additional Improvements:
- Add timestamp to filenames
- Implement motion-triggered video recording
- Add WiFi connectivity only when needed to upload files

Challenges to Consider

PIR sensors may have warm-up time (30-60 seconds after power on)
False triggers from pets or environmental changes
SD card writing can be power intensive
Battery life will still be limited for continuous operation

This approach will significantly reduce power consumption compared to continuous recording while still capturing all important events.

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