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.
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