Overview

The highest levels of API in regards to CoAP are all provided by the Serval Stack. It offers functionality such as a server, a client or general utilities when implementing a CoAP based application. This ensures that any message sent and received will be a CoAP message and treated as such.

Client Functionality

Function	Description
CoapServer_initialize()	This function is called to initialize the CoAP client (and server) and related modules. It must be called before any other CoAP-Client related function.
CoapServer_startInstance()	This function is called to start the CoAP client (and server). As input it receives a port, to which the server will listen, and a reference to a callbackfunction, which will be called every time the server receives a message.
CoapClient_initialize()	If it is desired to use different UDP sockets for server and client, this function must be called for the client instead of CoapServer_initialize. This function initializes only the client and relevant modules. Per default, this function is disabled.
CoapClient_startInstance()	This function is called to start the CoAP client after the client has been initialized using CoapClient_initialize. Per default, this function is disabled, if CoapClient_initialize is disabled, as well.
CoapClient_request()	This function is called to send a message as a request. As input, it receives a message, a callback for informing about the status of sending and a callback to handle a response to this message.
CoapClient_initReqMsg()	This function is called to initialize a message. As input, it receives the target’s IP address, its port and the pointer to a message.
Utility
CoapParser_setup()	This function sets up a CoAP-Parser which will be used to receive certain information from a CoAP-Message, such as the code, the payload or the options. As input, it receives a variable of type CoapParser_T and the pointer to a message.
CoapParser_getCode()	This function is called to receive the code of a message. As input, it receives a pointer to a message.
CoapParser_getPayload()	This function is called to receive the payload of a message. As input, it receives a pointer to the previously set up parser, a pointer to a payload array, and the array’s length.
CoapSerializer_setup()	This function sets up a CoAP-Serializer, which will be used to create a message. It handles setting options, the payload, the code, etc, for a given message. As input, it receives variable of type CoapSerializer_T, the pointer to a message, and a code indicating whether a RESPONSE or a REQUEST is created.
CoapSerializer_setCode()	This function is called to set the code of a message. As input, it receives the serializer, a message and the code to be set.
CoapSerializer_serializePayload()	This function is called to set the payload for a message. As input, it receives the serializer, a message pointer, the payload and the payload’s length