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ESP32-CAM

The ESP32-CAM enables visual reconnaissance capabilities for Espilon agents.

Overview

The ESP32-CAM is an ESP32 module with an integrated OV2640 camera sensor, providing:

  • 2MP image capture
  • Video streaming
  • Motion detection
  • SD card storage
  • Built-in LED flash

Recon Module Required

Camera features require the Recon module to be enabled at compile time.

Specifications

Component Specification
MCU ESP32-S (240MHz dual-core)
Flash 4MB
PSRAM 4MB (required for camera)
Camera OV2640 (2MP)
Resolution Up to 1600x1200 (UXGA)
SD Card MicroSD slot (up to 4GB)
LED Built-in flash LED (GPIO 4)
Price ~$8-15 USD

Supported Boards

AI-Thinker ESP32-CAM

The most common and recommended variant:

┌─────────────────────────────────────────────┐
│  [OV2640 Camera]                            │
│      ┌───┐                                  │
│      │   │                                  │
│      └───┘                                  │
│                                             │
│  ┌───────────────────────────────────────┐  │
│  │            ESP32-S Module             │  │
│  │                                       │  │
│  │  [Antenna]                            │  │
│  └───────────────────────────────────────┘  │
│                                             │
│  [SD Card Slot]        [Flash LED]          │
│                                             │
│  GND 3V3 U0R U0T GND VCC                   │
│   │   │   │   │   │   │                    │
└───┴───┴───┴───┴───┴───┴────────────────────┘

M5Stack ESP32 Camera

Alternative with better form factor:

  • Built-in battery holder
  • Grove connector
  • Better antenna design
  • Higher price (~$20)

Pinout

AI-Thinker ESP32-CAM

Pin Function Notes
5V/VCC Power input 5V recommended
GND Ground
U0T UART TX For flashing
U0R UART RX For flashing
GPIO 0 Boot mode Pull LOW to flash
GPIO 4 Flash LED Active HIGH
GPIO 33 Red LED Active LOW

Camera Pins (Internal)

These are fixed and cannot be changed:

GPIO Camera Function
32 PWDN
0 RESET
5 XCLK
18 SIOD
23 SIOC
36 Y9
37 Y8
38 Y7
39 Y6
35 Y5
34 Y4
21 Y3
19 Y2
22 VSYNC
25 HREF
26 PCLK

SD Card Pins

GPIO SD Function
14 CLK
15 CMD
2 DATA0
4 DATA1 (shared with Flash LED)
12 DATA2
13 DATA3

SD Card and Flash LED Conflict

GPIO 4 is shared between the flash LED and SD card DATA1. You cannot use both simultaneously.

Available GPIOs

Limited GPIOs available for external use:

Available: GPIO 1, 3 (UART0), GPIO 12, 13, 14, 15 (if not using SD card)
Reserved: All camera pins, SD card pins

Hardware Setup

Required Components

  • ESP32-CAM module
  • USB-to-Serial adapter (FTDI, CP2102, CH340)
  • Jumper wires
  • 5V power supply (USB or external)

Wiring for Flashing

Connect USB-to-Serial adapter to ESP32-CAM:

USB-Serial          ESP32-CAM
──────────          ─────────
   5V  ────────────── 5V
   GND ────────────── GND
   TX  ────────────── U0R (GPIO 3)
   RX  ────────────── U0T (GPIO 1)

   GND ────────────── GPIO 0 (for flashing only)

Boot Mode

GPIO 0 must be connected to GND during power-up to enter flash mode. Disconnect after flashing.

Flashing Procedure

  1. Connect GPIO 0 to GND
  2. Power cycle the board (disconnect and reconnect power)
  3. Flash the firmware: 
    idf.py -p /dev/ttyUSB0 flash
  4. Disconnect GPIO 0 from GND
  5. Power cycle again to boot normally

Power Supply

Power Requirements

The ESP32-CAM requires stable 5V power. USB-Serial adapters often cannot supply enough current.

Recommended power options:

Source Current Recommended
USB-Serial 3.3V 300mA max No
USB-Serial 5V 500mA max Marginal
External 5V PSU 1A+ Yes
USB power bank 1A+ Yes

ESP-IDF Configuration

Enable Recon Module

cd espilon_bot
idf.py menuconfig

Navigate to:

Espilon Configuration
  ├─ Module Selection
  │   └─ [X] Enable Recon Module
  │
  ├─ Recon Configuration
  │   ├─ Camera Model: AI-Thinker ESP32-CAM
  │   ├─ Default Resolution: VGA (640x480)
  │   ├─ JPEG Quality: 12 (0-63, lower = better)
  │   └─ Enable PSRAM: [X] (required)
  │
  └─ Network Backend
      └─ [X] WiFi (recommended for camera)

Camera Settings

Setting Options Recommendation
Resolution QQVGA to UXGA VGA (640x480) for balance
JPEG Quality 0-63 10-15 for good quality
Frame Size Various Match resolution
Brightness -2 to 2 0 (default)
Contrast -2 to 2 0 (default)

Build and Flash

# Build
idf.py build

# Flash (with GPIO 0 grounded)
idf.py -p /dev/ttyUSB0 flash

# Monitor
idf.py monitor

Commands

capture

Capture a single image:

c3po> send cam_agent capture

Response:
{
  "success": true,
  "size": 45320,
  "resolution": "640x480",
  "format": "JPEG",
  "data": "<base64_encoded_image>"
}

Save to file:

c3po> send cam_agent capture --save image.jpg
[*] Image saved to image.jpg (45320 bytes)

capture_settings

Adjust capture settings:

# Set resolution
c3po> send cam_agent capture_settings resolution VGA

# Set quality (0-63, lower = better)
c3po> send cam_agent capture_settings quality 10

# Enable flash
c3po> send cam_agent capture_settings flash on

# Adjust brightness (-2 to 2)
c3po> send cam_agent capture_settings brightness 1

stream_start

Start video streaming:

c3po> send cam_agent stream_start

Response:
{
  "success": true,
  "stream_url": "http://192.168.1.42:81/stream",
  "fps": 10
}

Streaming Bandwidth

Video streaming requires significant bandwidth. Use VGA or lower resolution over WiFi.

stream_stop

Stop video streaming:

c3po> send cam_agent stream_stop
[*] Stream stopped

motion_detect

Enable motion detection:

# Start motion detection
c3po> send cam_agent motion_detect start

# With sensitivity (1-100)
c3po> send cam_agent motion_detect start 50

# Stop motion detection
c3po> send cam_agent motion_detect stop

When motion is detected, the agent sends an alert:

{
  "type": "motion_alert",
  "timestamp": "2025-01-10T14:30:45Z",
  "image": "<base64_encoded_image>"
}

flash_led

Control the flash LED:

# Turn on
c3po> send cam_agent flash_led on

# Turn off
c3po> send cam_agent flash_led off

# Flash briefly (for capture)
c3po> send cam_agent flash_led pulse

Use Cases

Remote Surveillance

Deploy ESP32-CAM agents for visual monitoring:

graph LR
    CAM1[ESP32-CAM 1] -->|WiFi| C2[C2 Server]
    CAM2[ESP32-CAM 2] -->|WiFi| C2
    CAM3[ESP32-CAM 3] -->|WiFi| C2
    C2 --> OP[Operator]

Setup:

  1. Configure agents with unique IDs
  2. Position cameras at monitoring points
  3. Use capture for periodic snapshots
  4. Use motion_detect for event-triggered capture

Physical Security Assessment

Test physical security controls:

  • Identify camera blind spots
  • Test motion sensor coverage
  • Document access points
  • Capture evidence during pentest

Documentation

Capture visual evidence during assessments:

# Capture and save with timestamp
c3po> send cam_agent capture --save evidence_$(date +%Y%m%d_%H%M%S).jpg

Performance

Resolution vs Speed

Resolution Pixels Typical Size Capture Time
QQVGA 160x120 5-10 KB ~100ms
QVGA 320x240 15-25 KB ~200ms
VGA 640x480 40-60 KB ~400ms
SVGA 800x600 60-80 KB ~600ms
XGA 1024x768 80-120 KB ~1s
UXGA 1600x1200 150-250 KB ~2s

Streaming Performance

Resolution FPS (WiFi) Bandwidth
QQVGA 25-30 ~500 Kbps
QVGA 15-20 ~1 Mbps
VGA 8-12 ~2-3 Mbps
SVGA 5-8 ~4-5 Mbps

Optimization

For reliable operation, use VGA or lower resolution with quality 12-15.

Troubleshooting

Camera Not Detected

Symptoms: "Camera init failed" error

Solutions:

  1. Check PSRAM is enabled in menuconfig
  2. Verify camera ribbon cable is secure
  3. Try power cycling
  4. Check 5V power supply is adequate
# Verify PSRAM
idf.py menuconfig
# Component config -> ESP32-specific -> Support for external, SPI-connected RAM

Poor Image Quality

Symptoms: Blurry, dark, or noisy images

Solutions:

  1. Clean camera lens
  2. Adjust JPEG quality (lower number = better)
  3. Adjust brightness/contrast
  4. Ensure adequate lighting or use flash
c3po> send cam_agent capture_settings quality 8
c3po> send cam_agent capture_settings brightness 1

Brownout/Reboot

Symptoms: Device reboots during capture or streaming

Cause: Insufficient power supply

Solutions:

  1. Use external 5V 1A+ power supply
  2. Add 100uF capacitor across power pins
  3. Reduce resolution/quality
  4. Disable flash LED

WiFi Disconnects During Stream

Symptoms: Stream drops after a few seconds

Solutions:

  1. Reduce resolution
  2. Reduce frame rate
  3. Move closer to access point
  4. Use external antenna (if available)

Limitations

Hardware Constraints

  • Limited GPIOs available
  • SD card conflicts with flash LED
  • No UART during camera operation
  • PSRAM required (not all boards have it)

Performance Constraints

  • Single camera only
  • No hardware video encoding
  • WiFi bandwidth limits streaming
  • Power hungry during capture

Security Considerations

Operational Security

  • Camera captures can reveal operator location
  • Streaming traffic is high and detectable
  • Flash LED is visible
  • Consider privacy and legal implications

Comparison

ESP32-CAM vs USB Webcam

Feature ESP32-CAM USB Webcam
Standalone Yes No (needs PC)
Remote Yes (WiFi) No
Power 5V USB
Cost ~$10 ~$20+
Quality 2MP 1080p+
Form Factor Compact Larger

When to Use ESP32-CAM

  • Remote/wireless deployment
  • Battery-powered operation
  • Covert placement
  • Budget constraints

When to Use Alternative

  • High quality video needed
  • Wired connection available
  • PC-based operation acceptable

Resources

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