开发示例-MQTT客户端

开发示例——MQTT客户端新建名为mqttexpe文件夹，在文件夹下新建名为mqttexpe.c文件和BUILD.gn的文件。1.编写mqttexpe.c代码如下：#include"MQTTClient.h"#defineMQTT_BROKER"broker.emqx.io" //MQTTBroker的地址#defineMQTT_PORT 1883MQTTMessageackmsg;intneedAck=0;structopts_struct{char*clientid; //客户IDintnodelimiter; //有无分隔符标志char*delimiter; //分隔符enumQoSqos; //服务质量char*username; //用户名char*password; //密码char*host; //服务器地址intport; //端口号intshowtopics; //打印订阅的主题}opts={/**客户ID是唯一的，不可重复，重复会把前面连接的挤下线**/(char*)"mqtt_clientid_0",0,(char*)"\n",QOS2,NULL,NULL,(char*)MQTT_BROKER,MQTT_PORT,1};voidmessageArrived(MessageData*md){MQTTMessage*message=md->message;/**打印接收到的信息**/printf("%.*s",(int)message->payloadlen,(char*)message->payload);//根据message->payloadlen指示的宽度打印message->payload的一部分}unsignedcharbuf1[100];unsignedcharreadbuf[100];intMQTT_Test(void){intrc=0;MQTTMessagepubmsg;/**要订阅的主题**/char*topic="MQTT_PC";if(strchr(topic,'#')||strchr(topic,'+'))opts.showtopics=1;if(opts.showtopics)printf("topicis%s\n",topic);Networkmqtt_net;MQTTClientclient;/**网络初始化**/NetworkInit(&mqtt_net);/**网络连接**/rc=NetworkConnect(&mqtt_net,opts.host,opts.port);printf("Connected%d\n",rc);/**设置MQTT缓存**/MQTTClientInit(&client,&mqtt_net,1000,buf1,100,readbuf,100);/**启动MQTT任务**/rc=MQTTStartTask(&client);printf("Connected%d\n",rc);/**设置MQTT相关参数**/MQTTPacket_connectDatadata=MQTTPacket_connectData_initializer;data.willFlag=0;data.MQTTVersion=3;data.clientID.cstring=opts.clientid;data.username.cstring=opts.username;data.password.cstring=opts.password;data.keepAliveInterval=10;data.cleansession=1;printf("Connectingto%s%d\n",opts.host,opts.port);/**连接到MQTT服务器**/rc=MQTTConnect(&client,&data);printf("Connected%d\n",rc);printf("Subscribingto%s\n",topic);/**订阅主题和接收消息**/rc=MQTTSubscribe(&client,topic,opts.qos,messageArrived);printf("Subscribed%d\n",rc);/**设置消息参数**/memset(&ackmsg,'\0',sizeof(ackmsg));ackmsg.payload=(void*)"IamMCU";ackmsg.payloadlen=strlen((char*)ackmsg.payload);ackmsg.qos=QOS0;ackmsg.retained=0;ackmsg.dup=0;while(1){/**发送数据**/MQTTPublish(&client,"MQTT_MCU",&ackmsg);sleep(2);}printf("Stopping\n");/**断开MQTT的连接**/MQTTDisconnect(&client);/**关闭网络连接**/NetworkDisconnect(&mqtt_net);return0;}staticvoidMQTTTask(void*arg){(void)arg;sleep(12);MQTT_Test();}staticvoidMQTTTaskEntry(void){/**任务属性的结构体**/osThreadAttr_tattr; ="MQTTTask";//任务名称 attr.attr_bits=0U; //任务的属性位 attr.cb_mem=NULL;//任务控制块的内存初始地址，默认为系统自动分配 attr.cb_size=0U;//任务控制块的内存大小 attr.stack_mem=NULL;//任务的内存初始地址，默认为系统自动分配 attr.stack_size=4096; //任务的内存大小attr.priority=11; //任务的优先级 /**创建任务**/ if(osThreadNew((osThreadFunc_t)MQTTTask,NULL,&attr)==NULL){ printf("[MQTTTaskEntry]FaliedtocreateMQTTTask!\n"); }}/**让系统运行指定的函数**/SYS_RUN(MQTTTaskEntry);2.编写BUILD.gn如果按照11.2.1节完成了PahoMQTT库移植的所有步骤，则BUILD.gn代码如下：#将预编译的PahoMQTT静态库libpahomqtt_static.a复制到输出目录config_file=["//third_party/libs/libpahomqtt_static.a"]copy("config"){sources=config_fileoutputs=["//out/hispark_pegasus/wifiiot_hispark_pegasus/libs/{{source_file_part}}"]}#编译mqttexpe静态库static_library("mqttexpe"){sources=["mqttexpe.c",]#编译选项，禁用特定编译器警告，#以兼容PahoMQTT库代码规范（该库可能存在警告）cflags=["-Wno-unused-variable"]cflags+=["-Wno-unused-but-set-variable"]#头文件依赖路径include_dirs=["//utils/native/lite/include","//kernel/liteos_m/kal/cmsis","//device/hisilicon/hispark_pegasus/sdk_liteos/include","//foundation/communication/wifi_lite/interfaces/wifiservice","//third_party/cJSON","//third_party/lwip/src/include/lwip","//third_party/lwip/src/include/lwip/apps","//third_party/musl/porting/liteos_m/kernel/include/netinet","//third_party/pahomqtt/MQTTClient-C/src","//third_party/pahomqtt/MQTTClient-C/src/liteOS","//third_party/pahomqtt/MQTTPacket/src",]deps=[":config"]}如果按照11.2.1节完成了PahoMQTT库移植的前4步，省略了第5、6步，则BUILD.gn中不需要预先复制PahoMQTT静态库文件到out目录，其代码和其他案例差不多，具体如下：static_library("mqttexpe"){sources=["mqttexpe.c",]include_dirs=["//utils/native/lite/include","//kernel/liteos_m/kal/cmsis","//device/hisilicon/hispark_pegasus/sdk_liteos/include","//foundation/communication/wifi_lite/interfaces/wifiservice","//third_party/cJSON","//third_party/lwip/src/include/lwip","//third_party/lwip/src/include/lwip/apps","//third_party/musl/porting/liteos_m/kernel/include/netinet","//third_party/pahomqtt/MQTTClient-C/src","//third_party/pahomqtt/MQTTClient-C/sr