My first assignment on our WIMP project is to experiment with COAP. I started by readings and understanding the architecture of COAP vs. MQTT. The second day I decided to get hands on experience with COAP and started coding a client and a server.  This approach was much more interesting and educative.  Since I had to code in Java (for the first time) I started by downloading Californium by following the tutorial on  In a couple of hours I had my server and client running ;)