WiFI/Ethernet client with CoAP

This sample is available on GitHub in the https://github.com/lab5e/libcoap-dtls-sample repository. An in-depth description of the sample can be found in this blog post.

This is a CoAP client sample for Raspberry Pi/Linux with the libcoap library. This sample uses the built-in transport layer included with the library.

This example builds on Linux/Raspberry Pi but should be relatively simple to port to other frameworks that is built on top of the libcoap library such as ESP-IDF for the ESP32.

Client certificate and private key

The sample code reads the certificate and private key from the files cert.crt and key.pem. Both files must be PEM-encoded. The cert.crt contains the client certificate, intermediates and root and the key.pem file contains the private key.

Use the span CLI to generate a certificate and key file.


Install libcoap headers:

sudo dnf install libcoap-devel

Build with make