Door Closer ESP32

An ESP32-based automatic door closer system that uses a linear actuator to automatically close doors when they're left open. The system includes a WiFi web server that can receive door state events from external applications (like iOS apps) and automatically control the door closing mechanism.

Features

• WiFi-enabled: Connects to your local WiFi network for remote control
• Automatic door closing: Uses a linear actuator to physically close doors
• Web server interface: Simple HTTP endpoints for door state management
• Safety features: Built-in initialization sequence and timing controls
• Serial monitoring: Comprehensive logging for debugging and monitoring

Hardware Requirements

Core Components

• ESP32 Development Board (any ESP32 variant)
• L298N H-Bridge Motor Driver for controlling the linear actuator
• 12V Linear Actuator (200mm stroke recommended)
• 12V Power Supply for the actuator
• Breadboard and jumper wires for connections

Pin Connections

ESP32 Pin	L298N Connection	Purpose
Pin 25	IN1	Forward/Extend control
Pin 26	IN2	Reverse/Retract control
3.3V	VCC	Logic power (if needed)
GND	GND	Common ground

Circuit Diagram

ESP32                    L298N                    Linear Actuator
+----+                   +----+                   +----+
|    |                   |    |                   |    |
| 25 |------------------>|IN1 |------------------>|    |
|    |                   |    |                   |    |
| 26 |------------------>|IN2 |------------------>|    |
|    |                   |    |                   |    |
|GND |------------------>|GND |------------------>|    |
+----+                   +----+                   +----+
                              |
                              v
                          12V Power Supply

Software Setup

Prerequisites

• Arduino IDE with ESP32 board support
• Required libraries: WiFi.h (included with ESP32 core)

Configuration

1. Open closer/closer.cpp in Arduino IDE
2. Update WiFi credentials:

   const char *ssid = "Your WiFi name";
   const char *password = "Your WiFi password";

3. Verify pin assignments match your hardware setup
4. Upload the code to your ESP32

Usage

Initialization

When the ESP32 starts up, it automatically:

1. Connects to WiFi
2. Starts the web server
3. Runs a 23-second initialization sequence to retract the actuator to a known position
4. Becomes ready to receive door events

Web Server Endpoints

The ESP32 creates a simple web server with these endpoints:

• GET / - Status page showing the door controller is ready
• GET /open - Triggers the door closing sequence
• GET /closed - Logs that the door is closed (informational only)

Door Closing Sequence

When /open is triggered, the system automatically:

1. Extends the actuator for 20 seconds to push the door closed
2. Retracts the actuator for 20 seconds to return to neutral position
3. Stops and waits for the next door event

Total cycle time: 40 seconds

Example Usage

Using curl

# Trigger door closing
curl http://[ESP32_IP_ADDRESS]/open

# Check status
curl http://[ESP32_IP_ADDRESS]/

Using a web browser

Navigate to http://[ESP32_IP_ADDRESS]/open to trigger door closing

iOS App Integration

The system is designed to work with iOS apps that can send HTTP requests when door sensors detect an open door.

Serial Monitor Output

The ESP32 provides detailed logging via Serial Monitor (115200 baud):

L298N H-Bridge initialized
Connecting to Your WiFi name
.....
WiFi connected.
IP address: 192.168.1.100
Door controller server started!
Initializing: RETRACTING actuator to known position (23 seconds)...
Initialization complete - Actuator in retracted position
Ready to receive door events!
New Client.
open
Door is OPEN! Activating linear actuator...
Starting linear actuator: EXTENDING to close door
Linear actuator: EXTENDING back to neutral (20 seconds)
Door closing sequence complete - actuator stopped
Total cycle time: 40 seconds

Safety Features

• Initialization sequence: Ensures the actuator starts from a known position
• Prevent multiple activations: Won't start a new closing sequence while one is in progress
• Timing controls: Prevents the actuator from running indefinitely
• Hardware protection: Uses H-bridge for proper motor control

Troubleshooting

Common Issues

1. WiFi Connection Failed

   • Verify SSID and password are correct
   • Check WiFi signal strength
   • Ensure 2.4GHz network (ESP32 doesn't support 5GHz)

2. Actuator Not Moving

   • Check power supply voltage (should be 12V)
   • Verify pin connections
   • Check Serial Monitor for error messages

3. Door Closing Too Fast/Slow

   • Adjust timing values in the code (currently 20 seconds per phase)
   • Consider actuator stroke length and door weight

Debug Mode

Enable detailed logging by monitoring the Serial output at 115200 baud.

Customization

Timing Adjustments

Modify these values in the code to match your specific setup:

if (elapsed >= 23000)  // 23 seconds initialization
if (elapsed >= 20000)  // 20 seconds for full stroke

Pin Changes

Update these constants if using different ESP32 pins:

const int IN1_PIN = 25;  // Change as needed
const int IN2_PIN = 26;  // Change as needed

License

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

Contributing

Contributions are welcome! Please feel free to submit issues, feature requests, or pull requests.

Support

For issues or questions:

1. Check the troubleshooting section above
2. Review the Serial Monitor output
3. Verify hardware connections
4. Check WiFi network compatibility

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Note: This system is designed for residential use with standard interior doors. For commercial or heavy-duty applications, consider using industrial-grade components and additional safety mechanisms.