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Capture Moving Objects

Overview​

This solution demonstrates how to utilize a PIR sensor to achieve intelligent motion detection and automatic capture functionality, providing a low-power solution for scenarios such as security monitoring and smart homes.

Technical Background​

Passive Infrared Sensor (PIR) detects motion by sensing changes in infrared radiation. Key technical features include:

  • Detection Range: 3-7 meters (depending on the specific model)
  • Detection Angle: 110° horizontal × 90° vertical wide-angle coverage
  • Power Characteristics: Operates at 3.3V-5V
  • Energy Efficiency: Ultra-low standby power consumption, ideal for battery-powered devices

Development Preparation​

Hardware Configuration​

  • Main Control Unit: ESP32-S3 core development board
  • Sensor Module: PIR motion detection sensor
  • Power Supply System: Lithium battery pack (optional)

Software Resources​

1. Quick Deployment Firmware​

2. Development Environment Configuration​

  • Development Tool: Visual Studio Code (v1.99.2+)
  • Development Framework: ESP-IDF plugin (v5.1.6)
  • Sample Code Repository: lowpower_camera

Function Verification​

Precompiled Firmware Usage Guide​

1. Hardware Connection​

  1. Connect the PIR sensor to the specified interface on the development board.
  2. Ensure a stable power supply.

For detailed wiring instructions, refer to: Hardware Connection Guide

2. Firmware Flashing​

Follow the standard flashing process: System Flashing and Initialization Guide

3. Function Testing​

  1. Power on the device and complete initialization.
  2. Enter low-power standby mode.
  3. Trigger the PIR sensor:
    • Observe the status indicator light response.
    • Verify the automatic capture and upload functionality.

For the complete testing process, refer to: Quick Start Guide

Source Code Development Verification Process​

1. Obtain the Code Repository​

git clone https://github.com/camthink-ai/lowpower_camera.git

2. Project Configuration​

Open the project directory with VS Code:

Project Directory Structure

3. Key Configuration Items​

  1. GPIO Settings:
    • Use RTC GPIO to support wake-up functionality.
    • Avoid external pull-up interference.

GPIO Configuration

  1. Sensitivity Adjustment:
    • Adjust detection parameters based on the application scenario.

Sensitivity Parameter Configuration

4. Compilation and Deployment​

  1. Select the ESP32-S3 target chip:

Chip Selection Interface

  1. Execute project compilation:

Compilation Process

  1. Flash the generated firmware:

Firmware Flashing Interface

5. Function Verification​

The testing method is the same as for the precompiled firmware.

Optimization Suggestions​

Power Management Strategy​

  • Set a reasonable trigger interval (recommended ≥ 30 seconds).

Anti-Interference Measures​

  • Increase the PULSE_C parameter value (recommended 2-3 seconds).
  • Keep away from motors, inverters, and other sources of interference.

Environmental Adaptation Suggestions​

  • Recommended installation height: 1.5-2 meters.
  • Avoid direct sunlight on the sensor window.
  • Regularly clean the sensor lens.
  • Adjust the detection angle according to the scenario.

Debugging Tips:

  1. Use a logic analyzer to monitor GPIO signals.
  2. Analyze serial logs to identify the causes of false triggers.