ProsecCoAP 🥂 - CoAP client/server library for Arduino

Constrained Application Protocol (CoAP) server/client library for Arduino IDE/PlatformIO, ESP32, ESP8266.

Documentation is available at https://decadenza.github.io/ProsecCoAP/.

Details

This library is an implementation of CoAP protocol (RFC-7252). The aim is to provide all the compulsory functionalities, maintaining the execution lightweight and clearly documenting its API.

Please open an issue to request missing functionalities or report bugs.

How to install

Install from Arduino IDE Library Manager

1. Open the Sketch menu in the IDE.
2. Navigate to Include Library > Manage Libraries.
3. Search for "ProsecCoAP" and install.

Install from PlatformIO CLI

pio pkg install --library "ProsecCoAP"

Manual install

1. Download this source code branch as a zip file.
2. In the Arduino IDE, navigate to Sketch > Include Library > Add .ZIP Library. At the top of the drop down list, select the option to "Add .ZIP Library".

Getting started

A simple server can be started as:

#include <Ethernet.h>
#include <EthernetUdp.h>
#include <ProsecCoAP.h>
 
// Initialise a node.
EthernetUDP Udp;
Coap::Node coapNode(Udp);
 
byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD};
IPAddress deviceIp(192, 168, 0, 99);
 
// Your custom callback declaration.
void myCallback(Coap::Message &message, IPAddress ip, uint16_t port);
 
void setup()
{
  Ethernet.begin(mac, deviceIp);
  coapNode.serve("my-endpoint", myCallback);
  coapNode.start();
}
 
void loop() {
  coapNode.loop();
}
 
 
// Send "42" as a response to a GET request.
void myCallback(Coap::Message &message, IPAddress ip, uint16_t port)
{
  if (message.getCode() == Coap::MessageCode::GET)
  {
    Coap::Message response;
    message.buildResponse(Coap::MessageCode::CONTENT, response);
    response.addPayload((const uint8_t *)("42"), 2, Coap::ContentFormat::TEXT_PLAIN);
    coapNode.sendMessage(response, ip, port);
  }
}

Navigate to File > Examples > ProsecCoAP in Arduino IDE or check the example folder for more examples.

Run the examples

For the examples to compile and work correctly, please ensure to have all the necessary boards installed. The examples need standard libraries, like:

• Ethernet by Arduino
• WiFi by Arduino

Refer to the comments in each example for details.

How to test

Verify compile errors and warnings for multiple boards

To quickly verify a successful build process for multiple boards:

1. Install Arduino CLI.
2. Ensure the core for the supported boards are installed:

   arduino-cli core install arduino:avr
   arduino-cli core install esp32:esp32
   arduino-cli core install esp8266:esp8266 --additional-urls http://arduino.esp8266.com/stable/package_esp8266com_index.json

3. Run make.

Functional tests through the examples

The examples need another CoAP node to be executed. You can, alternatively:

• Use two devices and check serial monitor of each.
• Use one device and a CoAP tool on your computer for testing. For example, libcoap by compiling it yourself or use the example binaries available as Debian package libcoap3-bin. In this case, you can test with coap-client-notls and coap-server-notls.

Documentation

Documentation is available at: https://decadenza.github.io/ProsecCoAP/. It points to the main branch.

Building the documentation

To manually build documentation in your current working directory, run:

doxygen

The documentation will be accessible from ./html/index.html.

Credits

This library was inspired by CoAP-simple-library. Credits for the original code go to the original contributors. This project maintains the original MIT License and continues the spirit of open-source IoT development.