The Constrained Application Protocol (CoAP) is a UDP based transfer protocol for use with constrained nodes and constrained (e.g., low-power, lossy) networks. CoAP is based on RESTful API.
CoAP is an IETF standard, see https://datatracker.ietf.org/doc/rfc7252 for details.
The request response module is used for interaction between the server and client endpoints. The server exposes resources that the client can get, update, and delete.
The examples included in this SDK provide LED state information about LED_3 and LED_4 as resources. The client application can change the state of the LEDs using a CoAP PUT request. These examples do not support DELETE or POST operations.
Figure 1: Setup of CoAP examples.
CoAP Server and Client Example applications detailed below: