Z3GatewayHost Mqtt 如何 publish 私有的数据

EFR32MG多协议SoC芯片是 Silicon Labs 专门针对 IOT 推出的 ZigBee 方案，高达19.5dbm的发射功率，-102.7dbm的接收灵敏度，在业界内拥有最佳的RF射频性能，具有最全的Zigbee网络协议，被广泛应用在智能家居，工业控制等行业。

 在开发 Zigbee Gateway 时，有时候需要自定义消息类型发送给 Mqtt Server 端，因此我们要 publish 自定义的数据。  

下面的参考代码是用户自定义的 deviceannounce topic 的数据。

static void publishMqttDeviceAnnounce(EmberEUI64 eui64,EmberNodeId nodeId,uint8_t capInfo);//add by sven 

static void publishMqttDeviceAnnounce(EmberEUI64 eui64,EmberNodeId nodeId,uint8_t capInfo)
{
    //This function call breaks simulation test, mask it out
    //at this point as Mqtt messages are actually not included
    //in simluation test. It works normally with the real devices.
#ifndef EMBER_TEST
    cJSON* deviceAnnounceJson;
    char euiString[EUI64_STRING_LENGTH] = { 0 };
    char nodeIdString[NODEID_STRING_LENGTH] = { 0 };
    eui64ToString(eui64, euiString);
    nodeIdToString(nodeId, nodeIdString);
    deviceAnnounceJson = cJSON_CreateObject();
    cJSON_AddStringToObject(deviceAnnounceJson, "nodeId", nodeIdString);
    cJSON_AddStringToObject(deviceAnnounceJson, "eui64", euiString);
    cJSON_AddIntegerToObject(deviceAnnounceJson, "capabilityInfo", capInfo);
    publishMqttTopic("deviceannounce", deviceAnnounceJson);
#endif //EMBER_TEST
}

在这里参考代码中包含了 cJSON 数据结构的创建，赋值及发送的整个流程。不同类型需要调用不同的函数，例如：

#define cJSON_AddNullToObject(object,name)       cJSON_AddItemToObject(object, name, cJSON_CreateNull())

#define cJSON_AddTrueToObject(object,name)       cJSON_AddItemToObject(object, name, cJSON_CreateTrue())

#define cJSON_AddFalseToObject(object,name)       cJSON_AddItemToObject(object, name, cJSON_CreateFalse())

#define cJSON_AddBoolToObject(object,name,b)       cJSON_AddItemToObject(object, name, cJSON_CreateBool(b))

#define cJSON_AddDoubleToObject(object,name,n)       cJSON_AddItemToObject(object, name, cJSON_CreateDouble(n))

#define cJSON_AddIntegerToObject(object,name,n)       cJSON_AddItemToObject(object, name, cJSON_CreateInteger(n))

#define cJSON_AddStringToObject(object,name,s)       cJSON_AddItemToObject(object, name, cJSON_CreateString(s))