Overview
Build a motion-activated security system that detects movement with a PIR sensor, captures a snapshot from an IP camera, and emails the image to you as an alert. An LED indicator provides local visual feedback when motion is detected. A 10-second debounce delay prevents repeated alerts from a single event.
What You'll Need
Hardware
- * Raspberry Pi (any model with GPIO)
- * HC-SR501 PIR motion sensor
- * LED + 220Ω resistor (indicator)
- * IP camera with HTTP snapshot URL (e.g., ESP32-CAM, Wyze, Tapo)
- * Jumper wires
Software / Accounts
- * EdgeFlow installed on your Pi
- * SMTP email credentials (Gmail, Outlook, etc.)
- * IP camera accessible on your local network
Wiring Diagram
PIR Sensor (HC-SR501)
VCC → 5V (Pin 2)
OUT → GPIO17 (Pin 11)
GND → GND (Pin 6)
LED Indicator
Anode (+) → 220Ω resistor → GPIO27 (Pin 13)
Cathode (-) → GND (Pin 14)
Importable Flow JSON
Copy this JSON and import it via Menu → Import in the EdgeFlow editor.
{
"name": "Motion-Activated Security System",
"nodes": [
{
"id": "pir_1",
"type": "pir",
"name": "PIR Motion Sensor",
"pin": 17,
"edge": "rising",
"debounce": 200,
"x": 120,
"y": 200
},
{
"id": "delay_debounce",
"type": "delay",
"name": "10s Debounce",
"timeout": 10,
"timeoutUnits": "seconds",
"rateAction": "drop",
"x": 320,
"y": 200
},
{
"id": "led_on",
"type": "change",
"name": "LED ON",
"rules": [
{ "t": "set", "p": "payload", "to": 1 }
],
"x": 320,
"y": 100
},
{
"id": "led_off_delay",
"type": "delay",
"name": "LED 3s Timer",
"timeout": 3,
"timeoutUnits": "seconds",
"x": 500,
"y": 100
},
{
"id": "led_off",
"type": "change",
"name": "LED OFF",
"rules": [
{ "t": "set", "p": "payload", "to": 0 }
],
"x": 660,
"y": 100
},
{
"id": "gpio_led",
"type": "gpio-out",
"name": "LED Indicator",
"pin": 27,
"mode": "digital",
"x": 840,
"y": 100
},
{
"id": "snapshot",
"type": "http-request",
"name": "Camera Snapshot",
"method": "GET",
"url": "http://192.168.1.100/capture",
"returnType": "bin",
"x": 520,
"y": 200
},
{
"id": "format_email",
"type": "function",
"name": "Format Email",
"func": "msg.to = 'your-email@example.com';\nmsg.subject = 'Motion Detected - ' + new Date().toLocaleString();\nmsg.body = 'Motion was detected by the PIR sensor.\\nTimestamp: ' + new Date().toISOString();\nif (msg.payload) {\n msg.attachments = [{ filename: 'snapshot.jpg', content: msg.payload }];\n}\nreturn msg;",
"x": 720,
"y": 200
},
{
"id": "email_send",
"type": "email",
"name": "Send Email Alert",
"smtp": "smtp.gmail.com",
"port": 587,
"secure": true,
"user": "your-email@gmail.com",
"password": "YOUR_APP_PASSWORD",
"x": 920,
"y": 200
},
{
"id": "debug_1",
"type": "debug",
"name": "Motion Log",
"x": 520,
"y": 320
}
],
"connections": [
{ "from": "pir_1", "to": "delay_debounce" },
{ "from": "pir_1", "to": "led_on" },
{ "from": "led_on", "to": "gpio_led" },
{ "from": "led_on", "to": "led_off_delay" },
{ "from": "led_off_delay", "to": "led_off" },
{ "from": "led_off", "to": "gpio_led" },
{ "from": "delay_debounce", "to": "snapshot" },
{ "from": "delay_debounce", "to": "debug_1" },
{ "from": "snapshot", "to": "format_email" },
{ "from": "format_email", "to": "email_send" }
]
}Step-by-Step Walkthrough
Wire the PIR Sensor and LED
Connect the HC-SR501 PIR sensor to 5V, GND, and GPIO17. Set the jumper on the PIR to "H" (repeatable trigger) mode. Wire an LED with a 220Ω resistor to GPIO27 as a visual motion indicator.
Set Up Your IP Camera
Find the snapshot URL for your IP camera. Common formats:
ESP32-CAM: http://192.168.1.100/capture
Tapo C200: http://192.168.1.101/stream/snapshot.jpg
Generic: http://CAMERA_IP/snapshot.cgi?user=admin&pwd=passwordDouble-click the "Camera Snapshot" node and set the URL to your camera's snapshot endpoint.
Configure Email SMTP
Double-click the "Send Email Alert" node and enter your SMTP settings. For Gmail, you need to create an App Password (not your regular password):
| Provider | Server | Port |
|---|---|---|
| Gmail | smtp.gmail.com | 587 |
| Outlook | smtp.office365.com | 587 |
| Yahoo | smtp.mail.yahoo.com | 465 |
Deploy and Test
Click Deploy and wait 60 seconds for the PIR sensor to warm up. Walk in front of the sensor to trigger a detection. The LED should light up for 3 seconds, and you should receive an email with a camera snapshot within a few seconds.
Configuration Details
| Parameter | Value | Description |
|---|---|---|
| PIR Edge | Rising | Triggers on motion start (LOW → HIGH) |
| PIR Debounce | 200 ms | Hardware debounce to ignore electrical noise |
| Alert Debounce | 10 seconds | Prevents duplicate alerts from sustained motion |
| LED Duration | 3 seconds | How long the indicator LED stays on |
| Camera Format | Binary (JPEG) | HTTP request returns raw image data for email attachment |
Expected Output
The PIR node sends this message when motion is detected:
{
"payload": 1,
"pin": 17,
"edge": "rising",
"timestamp": 1707750123456,
"_msgid": "f5e6d7c8"
}After the HTTP request, the formatted email message looks like:
{
"to": "your-email@example.com",
"subject": "Motion Detected - 2/12/2026, 3:45:12 PM",
"body": "Motion was detected by the PIR sensor.\nTimestamp: 2026-02-12T15:45:12.456Z",
"attachments": [
{
"filename": "snapshot.jpg",
"content": "<Buffer ff d8 ff e0 ... 42,319 bytes>"
}
]
}Troubleshooting
PIR sensor triggers constantly (false positives)
- Reduce the sensitivity potentiometer on the PIR module
- Avoid pointing the sensor at windows, heating vents, or fans
- Increase the debounce delay node timeout to 30s
- Ensure the sensor has a stable 5V power supply
Camera snapshot returns an error
- Verify the camera IP address is correct and reachable from the Pi
- Test the snapshot URL in a browser first
- Check if the camera requires authentication
- Ensure the HTTP Request node is set to return "Binary" data
Email fails to send
- For Gmail: use an App Password, not your account password
- Verify SMTP server and port are correct
- Check the Pi has internet access
- Look at the Debug panel for detailed SMTP error messages