You’ve taught your Raspberry Pi to see—now it’s time to make it react. In this lesson, you’ll transform your AI-powered Pi into a smart security system that can send alerts or trigger devices when it sees a human in a specific area.
🎯 What You’ll Learn Today:
- How to define a Region of Interest (ROI) in a video feed
- How to detect when a person enters that region
- How to send a photo alert via Telegram, Discord, or email when someone is detected
- How to begin integrating real-world automation with vision-based triggers
🚨 Today's Project:
Build a Security Camera Alert System
- When a person steps into a defined zone → snap a photo
- Instantly send that image to your phone using a webhook or bot
🔧 Code Workflow Overview:
- Start the camera feed using OpenCV or Picamera2
- Load your object detection model (TFLite recommended)
- Define a Region of Interest (ROI) on screen using pixel coordinates
- In your detection loop:
- ➡ If a "person" is detected inside the ROI →
- 📸 Capture a frame
- 📤 Send the image + message to Discord or Telegram
⚠️ Safety Reminder:
Do not connect Raspberry Pi GPIO to high-voltage AC devices unless you’re experienced and know proper electrical safety procedures. Use low-voltage relays or smart plugs for automation tasks.
💡 Creative Extensions:
- Add a countdown timer so the light or alarm turns off automatically
- Limit triggers to certain times of day for quiet hours
- Use OpenCV to track how long a person stays inside the zone
→ Only trigger if they linger for >10 seconds
📝 Homework:
- Choose Option A (Telegram) or Option B (Discord) and build your alert system
- Share a photo or short video of your system in action in the #MONTH3 thread on Discord
🔥 Bonus Challenge: Set up multiple zones that trigger different responses
🚀 Up Next:
You’ve given your Pi eyes—now we’ll give it ears. In Lesson 5, we’ll dive into voice recognition and text-to-speech so you can build your own talking AI assistant.