MicroPython-CoAP-Server-Client

This repository contains a MicroPython-based CoAP (Constrained Application Protocol) Server and Client implementation for IoT devices. The project demonstrates how to use CoAP for communication between IoT devices and a server, enabling efficient and lightweight data exchange in constrained environments.

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Features

• CoAP Server:

  • Hosts a CoAP resource for sensor data (e.g., temperature, humidity, light level, bin fill level).
  • Responds to GET requests with sensor data in JSON format.
  • Supports multiple endpoints for different resources.

• CoAP Client:

  • Fetches LED status from a remote CoAP server (e.g., Spring Boot CoAP server).
  • Updates LEDs based on the received status.

• Sensor Integration:

  • Reads data from:
    • DHT22 (temperature and humidity sensor).
    • Light sensor (ADC).
    • Ultrasonic sensor (bin fill level).

• LED Control:

  • Controls LEDs (red, yellow, green) based on the status received from the CoAP server.

• Asynchronous Operation:

  • Uses uasyncio for non-blocking server and client operations.

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Hardware Requirements

• Microcontroller: ESP32 or similar MicroPython-compatible device.
• Sensors:
  • DHT22 (temperature and humidity).
  • Light sensor (ADC).
  • Ultrasonic sensor (HC-SR04).
• LEDs: Red, Yellow, Green.
• Wi-Fi connectivity.

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Software Requirements

• MicroPython: Firmware for the microcontroller.
• Python Libraries:
  • microcoapy: CoAP implementation for MicroPython.
  • DHT22: Library for reading temperature and humidity.
  • HCSR04: Library for ultrasonic sensor.
• Spring Boot CoAP Server: For testing the client (optional).

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Installation

1. Flash MicroPython:

   • Download the latest MicroPython firmware for your microcontroller from micropython.org.
   • Flash the firmware using esptool or a similar tool.

2. Upload Code:

   • Use ampy, rshell, or Thonny IDE to upload the Python files to your microcontroller.

3. Install Dependencies:

   • Upload the following libraries to your microcontroller:
     • microcoapy.py
     • dht.py
     • hcsr04.py

4. Configure Wi-Fi:

   • Update the connect_wifi() function in the code with your Wi-Fi SSID and password.

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Usage

1. CoAP Server

• The server hosts a CoAP resource at /sensors.
• To fetch sensor data, send a GET request to:

  coap://<device-ip>/sensors
  

• Example response:

  {
    "timestamp": "2025-01-30 14:22:15",
    "temperature": 25.6,
    "humidity": 45.0,
    "lightLevel": 512,
    "binLevel": 75.5
  }

2. CoAP Client

• The client fetches LED status from a remote CoAP server (e.g., Spring Boot CoAP server).
• The server should host a resource at /led-status.
• Example response:

  {
    "redLed": false,
    "yellowLed": true,
    "greenLed": false
  }

3. Run the Code

• Upload the main.py file to your microcontroller and reset the device.
• The server will start automatically, and the client will periodically fetch the LED status.

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Example Code

CoAP Server with Sensors

from machine import Pin, ADC
import network
import utime
import microcoapy
from coap_macros import COAP_METHOD
from hcsr04 import HCSR04
from dht import DHT22
import json

# Initialize sensors and pins
dht_sensor = DHT22(Pin(21))
light_sensor = ADC(Pin(34))
ultrasonic_sensor = HCSR04(trigger_pin=32, echo_pin=33)

# CoAP server setup
def setup_server():
    server = microcoapy.Coap()

    def sensor_handler(packet, sender_ip, sender_port):
        sensor_data = get_sensor_data()
        if sensor_data:
            response = json.dumps(sensor_data)
            server.sendResponse(sender_ip, sender_port, packet.messageid, response, 0x45, 0, packet.token)

    server.addIncomingRequestCallback('sensors', sensor_handler)
    return server

# Run the server
def run_server():
    connect_wifi('your-ssid', 'your-password')
    server = setup_server()
    server.start()
    print('CoAP server started. Waiting for requests...')

    while True:
        server.poll(10000)

# Main function
if __name__ == '__main__':
    run_server()

CoAP Client for LED Control

import microcoapy
import json

def fetch_led_status():
    client = microcoapy.Coap()

    def received_message_callback(packet, sender):
        if packet.method == 0x45:  # 2.05 Content
            led_states = json.loads(packet.payload.decode('utf-8'))
            print("Received LED status:", led_states)
            # Update LEDs here

    client.responseCallback = received_message_callback
    client.start(port=0)
    client.get('192.168.1.2', 5683, 'led-status')
    client.poll(10000)
    client.stop()

# Main function
if __name__ == '__main__':
    fetch_led_status()

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Contributing

Contributions are welcome! Please follow these steps:

1. Fork the repository.
2. Create a new branch:

   git checkout -b feature-branch
   

3. Commit your changes:

   git commit -m 'Add new feature'
   

4. Push to the branch:

   git push origin feature-branch
   

5. Open a pull request.

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License

This project is licensed under the MIT License. See the LICENSE file for details.

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Acknowledgments

• MicroPython for providing the firmware.
• CoAP for the lightweight communication protocol.
• Spring Boot CoAP for the CoAP server implementation.

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Contact

For questions or feedback, please open an issue or contact the maintainer:

Irfan Ullah

• GitHub: Irfan-Ullah-cs
• Email: imirfan.cs@gmail.com