RoomSpy Hardware

This Repo contains the firmware code for RoomSpy in ./esp.ino, a room occupancy monitoring system using the HC-SR501 Motion Sensor and ESP32 microcontroller. The system detects motion, determines room occupancy status, and communicates with a backend API over WiFi.

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Hardware Requirements

1. ESP32 microcontroller
2. HC-SR501 Motion Sensor
3. LEDs for status indication:
   • Built-in LED (WiFi connection indicator)
   • External LED for error indication
4. Power supply and wires for connections

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How It Works

1. Motion Detection: The HC-SR501 sensor detects motion and triggers an interrupt.
2. Room Occupancy Logic:
   • Tracks motion events in a rolling time window (default: 10 entries).
   • Considers the room "occupied" if at least one motion event occurs within the last minute.
3. WiFi Communication:
   • Connects to a specified WiFi network.
   • Sends room occupancy status updates to a backend API in JSON format.
4. Status Indication:
   • Built-in LED blinks during WiFi connection and stays solid when connected.
   • Error LED blinks if a failure occurs while sending data or reconnecting WiFi.

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Setup Instructions

Hardware Setup

1. Connect the HC-SR501 sensor to the ESP32:
   • VCC: 5V
   • GND: GND
   • OUT: GPIO 34
2. Connect an external error LED to GPIO 12.
3. Power the ESP32.

Firmware Configuration

1. Update the WiFi credentials in the code:

   const char* ssid = "[WIFI SSID]";         // Your WiFi SSID
   const char* password = "[WIFI PASSWORD]"; // Your WiFi password

2. Replace the backend API URL:

   const char* serverUrl = "https://[BACKEND API URL]";

3. Customize the room name if needed:

   const char* RoomName = "Damietta";

Uploading Code

1. Open the code in the Arduino IDE or your preferred development environment.
2. Select the correct board (ESP32) and port.
3. Compile and upload the code to the ESP32.

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Operation

• The system automatically connects to WiFi on boot.
• When motion is detected, the system:
  • Updates the rolling motion timestamps.
  • Checks and updates the room's occupancy status.
  • Sends the status to the backend API if there's a change or periodically (every minute).
• The built-in LED indicates WiFi connection status.
• The error LED blinks if communication with the backend API fails.

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Code Highlights

Motion Detection

void IRAM_ATTR handleMotion() {
  motionDetected = true;
}

Room Status Update

void updateRoomStatus() {
  bool occupied = motionCount >= 1;  // Detects occupancy based on motion within the window
  if (occupied != roomOccupied) {
    roomOccupied = occupied;
    sendStatusData(roomOccupied);
  }
}

Sending Data to API

void sendStatusData(bool occupied) {
  String payload = "{\"RoomName\": \"" + String(RoomName) + "\", \"occupied\": " + String(occupied ? "true" : "false") + ", \"timestamp\": " + String(millis()) + "}";
  // Sends the data using HTTP POST
}

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Customization

• Rolling Window Size: Adjust motionWindowSize to modify the number of motion events tracked.
• Occupancy Threshold: Change the logic in updateRoomStatus to define custom thresholds for occupancy.

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Troubleshooting

1. No WiFi Connection:
   • Verify the SSID and password.
   • Ensure the WiFi network is active.
2. No API Updates:
   • Check the serverUrl value.
   • Ensure the backend API is reachable.
3. Unexpected Behavior:
   • Check the serial monitor for debugging messages.
   • Verify the motion sensor's wiring and orientation.

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License

This project is open-source. Feel free to modify and redistribute as needed.

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Enjoy monitoring your room with RoomSpy! 🚀