MQTT上报温度到阿里云
*
– 前言
– iniparser配置文件
– cJSON
– sqlite3数据库
– 流程图
– 配置信息
– 发布端代码实现
– 运行结果
前言
在上几篇文章中我们用MQTT.fx模拟客户端实现了与阿里云物联网平台的双向通信，接下来我们自己动手编程使用mosquitto库实现一个发布端。
iniparser配置文件
iniparser介绍
与阿里云进行通信时，我们需要如下一些信息，例如在使用MQTT.fx时：
阿里云配置和MQTT.fx使用
在上篇文章中阿里云配置文件另外之前发布和订阅的topic也要记下来：
这些都是我们在项目中要用到的配置信息，具体应用在：
#客户端id
clientid：
struct mosquitto *mosquitto_new( const char * id, bool clean_session, void * obj )
#连接阿里云的端口,主机名
brokeraddress and brokerport：
int mosquitto_connect( struct mosquitto * mosq, const char * host, int port, int keepalive )
#连接阿里云账号和密码
username and password：
int mosquitto_username_pw_set(struct mosquitto * mosq, const char *username, const char *password )
#订阅的主题
topic：
int mosquitto_publish( struct mosquitto * mosq, int * mid, const char * topic, int payloadlen, const void * payload, int qos, bool retain )
当然可以直接写死在代码里，但是这样一来，代码复用性不高，换一个设备那么就要改一次源码来更改设备配置信息。MQTT主机使用可以看这篇博客.
所以我们写一个.ini文件，这样当我们更换设备的时候只需要修改这个.ini文件中的信息即可。然后在代码中使用iniparser库中API。
cJSON
JSON(JavaScript Object Notation, JS 对象简谱) 是一种轻量级的数据交换格式。它基于 ECMAScript (欧洲计算机协会制定的js规范)的一个子集，采用完全独立于编程语言的文本格式来存储和表示数据。简洁和清晰的层次结构使得 JSON 成为理想的数据交换语言。 易于人阅读和编写，同时也易于机器解析和生成，并有效地提升网络传输效率。
阿里云上 payload must be json format 负载（消息）必须为cJSON格式。
因为使用的阿里云提供的标准物模型，所以消息格式应该遵循阿里云的规范。这就是我们要使用cJSON的原因。
要是已其他格式发送,阿里云收到了消息，但是因为参数不匹配，无法对消息进行解析，也就无法获取到温度消息
学习cJSON可以参考博客
sqlite3数据库
SQLite是一个进程内的库，实现了自给自足的、无服务器的、零配置的、事务性的 SQL 数据库引擎。它是一个零配置的数据库，这意味着与其他数据库不一样，您不需要在系统中配置。
就像其他数据库，SQLite 引擎不是一个独立的进程，可以按应用程序需求进行静态或动态连接。SQLite 直接访问其存储文件。
sqlite3数据库优点
1.不需要一个单独的服务器进程或操作的系统（无服务器的）。
2.SQLite 不需要配置，这意味着不需要安装或管理。
3. 一个完整的 SQLite数据库是存储在一个单一的跨平台的磁盘文件。
4. SQLite 是非常小的，是轻量级的，完全配置时小于 400KiB，省略可选功能配置时小于250KiB。
5.SQLite 是自给自足的，这意味着不需要任何外部的依赖。
6 SQLite 事务是完全兼容ACID 的，允许从多个进程或线程安全访问。
7.SQLite 支持 SQL92（SQL2）标准的大多数查询语言的功能。
8. SQLite 使用ANSI-C 编写的，并提供了简单和易于使用的 API。
9. SQLite 可在 UNIX（Linux, Mac OS-X, Android,iOS）和 Windows（Win32, WinCE, WinRT）中运行。
流程图
; 配置信息
#include "iniparser.h"
#include "mqtt_conf.h"
#include
#include
int get_config(char *path,mqtt_user_data *mqtt,int mode)
{
dictionary *ini = NULL;
const char *brokeraddress;
int brokerport;
const char *username;
const char *password;
const char *clientid;
const char *topic;
int Qos;
const char *method;
const char *time;
const char *jsonid;
const char *identifier;
const char *version;
if(!path || !mqtt)
{
printf("invalid_argument: %s\n",__FUNCTION__);
return -1;
}
ini = iniparser_load(path);
if(!ini)
{
printf("iniparser_load failed!\n");
return -1;
}
brokeraddress = iniparser_getstring(ini,"address:host",DEFAULT_BROKER_ADDRESS);
brokerport= iniparser_getint(ini,"address:port",DEFAULT_BROKER_PORT);
username = iniparser_getstring(ini,"user_name_pwd:username",DEFAULT_USERNAME);
password = iniparser_getstring(ini,"user_name_pwd:pwd",DEFAULT_PASSWORD);
clientid = iniparser_getstring(ini,"clientid:id",DEFAULT_CLIENTID);
identifier = iniparser_getstring(ini,"ali_json:identifier",DEFAULT_JSONID);
if(mode == SUB)
{
topic = iniparser_getstring(ini,"sub_topic:topic",DEFAULT_SUB_TOPIC);
}
else if(mode == PUB)
{
topic = iniparser_getstring(ini,"pub_topic:topic",DEFAULT_PUB_TOPIC);
method = iniparser_getstring(ini,"ali_json:method",DEFAULT_METHOD);
version = iniparser_getstring(ini,"ali_json:version",DEFAULT_VERSION);
}
else if(mode != SUB && mode != PUB)
{
printf("invalid_argument : %s mode!\n",__FUNCTION__);
return -1;
}
strncpy(mqtt->brokeraddress,brokeraddress,SIZE);
mqtt->brokerport = brokerport;
mqtt->Qos = Qos;
strncpy(mqtt->username,username,SIZE);
strncpy(mqtt->password,password,SIZE);
strncpy(mqtt->clientid,clientid,SIZE);
strncpy(mqtt->topic,topic,SIZE);
strncpy(mqtt->identifier,identifier,SIZE);
if(mode == PUB)
{
strncpy(mqtt->method,method,SIZE);
strncpy(mqtt->version,version,SIZE);
}
iniparser_freedict(ini);
return 0;
}
#ifndef MQTT_CONF_H
#define MQTT_CONF_H
#define SIZE 1024
#define KEEP_ALIVE 60
enum{
SUB ,
PUB
};
typedef struct mqtt_user_data
{
char brokeraddress[SIZE] ;
int brokerport;
char username[SIZE];
char password[SIZE];
char clientid[SIZE];
char topic[SIZE];
int Qos;
char method[SIZE] ;
char time[SIZE];
char jsonid[SIZE] ;
char identifier[SIZE] ;
char version[SIZE] ;
}mqtt_user_data;
int set_config(char *path,char *host,int port, char *clientid,char *uname,char *pwd,char *topic);
int get_config(char *path, mqtt_user_data *mqtt, int mode);
#endif
[address]
host = iot-06z00i99uliom9a.mqtt.iothub.aliyuncs.com
port = 1883
[user_name_pwd]
username = ds18b20&gr71iZ9S48c
pwd = 2a59fde4b9765b403df5bfe7ce63b06cfb79e7d57cb373a0dfa501f79623cc83
[clientid]
id = gr71iZ9S48c.ds18b20|securemode=2,signmethod=hmacsha256,timestamp=2524608000000|
[pub_topic]
topic = /sys/gr71iZ9S48c/ds18b20/thing/event/property/post
[sub_topic]
topic = /sys/gr71iZ9S48c/ds18b20/thing/service/property/set
[ali_json]
method = thing.service.property.set
id = ip
identifier = CurrentTemperature
version = 1.0.0
[KEEP_ALIVE]
alive = 60
[ali_Qos]
Qos = 0
发布端代码实现
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include "mqtt_conf.h"
#include "cJSON.h"
#include "dictionary.h"
#include "iniparser.h"
#include "ifconfig.h"
#include "db_sqlite3.h"
#define PROG_VERSION "1.0.0"
#define INI_PATH "./mqtt_aliyun.ini"
static int g_stop = 0;
void sig_handler(int sig_num)
{
if(sig_num == SIGUSR1)
g_stop = 1;
}
int db_init(sqlite3 *db,char *zErrMsg);
int db_table(char *zErrMsg, sqlite3 *db);
int db_store(sqlite3 *db,char *zErrMsg);
int get_temperature(float *temper);
int get_time (char *datetime,int len);
static inline void print_usage(char *progname);
char *create_json(void *obj);
void connect_callback(struct mosquitto *mosq,void *obj,int rc);
int main (int argc, char **argv)
{
char *progname = basename(argv[0]);
int brokerport = 1883;
char *brokeraddress = NULL;
char *clientid = NULL;
char *username = NULL;
char *password = NULL;
char *topic = NULL;
struct mosquitto *mosq = NULL;
int daemon_run = 0;
int opt = -1;
int rv;
int log_fd;
struct mqtt_user_data mqtt;
struct option options[] =
{
{"daemon",no_argument,NULL,'d'},
{"topic", required_argument,NULL,'t'},
{"brokeraddress", required_argument,NULL,'H'},
{"clientid", required_argument, NULL, 'i'},
{"brokerport",required_argument,NULL,'p'},
{"help",no_argument,NULL,'h'},
{"username",required_argument,NULL,'u'},
{"password",required_argument,NULL,'P'},
{NULL,0,NULL,0}
};
while((opt = getopt_long(argc,argv,"dhp:t:i:u:P:H:",options,NULL)) != -1)
{
switch(opt)
{
case 't':
topic = optarg;
break;
case 'i':
clientid = optarg;
break;
case 'H':
brokeraddress = optarg;
break;
case 'u':
username = optarg;
break;
case 'P':
password = optarg;
break;
case 'd':
daemon_run = 1;
break;
case 'p':
brokerport = atoi(optarg);
break;
case 'h':
print_usage(argv[0]);
return 0;
default:
break;
}
}
if(daemon_run)
{
printf("program %s running in backgrund\n", progname);
if( (log_fd = open("client.log", O_CREAT|O_RDWR, 0666)) < 0)
{
printf("open() failed:%s\n", strerror(errno)) ;
return -2;
}
dup2(log_fd, STDOUT_FILENO);
dup2(log_fd, STDERR_FILENO);
daemon(1,1);
}
signal(SIGUSR1,sig_handler);
memset(&mqtt,0,sizeof(mqtt));
rv = get_config(INI_PATH,&mqtt,PUB);
mosquitto_lib_init();
mosq = mosquitto_new(mqtt.clientid,true,(void *)&mqtt);
if(!mosq)
{
printf("mosquitto_new() failed: %s\n",strerror(errno));
goto cleanup;
return -1;
}
if(mosquitto_username_pw_set(mosq,mqtt.username,mqtt.password) != MOSQ_ERR_SUCCESS)
{
printf("mosquitto_username_pw_set failed: %s\n",strerror(errno));
goto cleanup;
}
printf("Create mosquitto successfully!\n");
mosquitto_connect_callback_set(mosq,connect_callback);
while(!g_stop)
{
if(mosquitto_connect(mosq, mqtt.brokeraddress,mqtt.brokerport,KEEP_ALIVE) != MOSQ_ERR_SUCCESS)
{
printf("mosquitto_connect() failed: %s\n",strerror(errno));
goto cleanup;
}
printf("connect successfully\n");
mosquitto_loop_forever(mosq,-1,1);
sleep(3);
}
cleanup:
close(log_fd);
mosquitto_destroy(mosq);
mosquitto_lib_cleanup();
return 0;
}
void print_usage(char *progname)
{
printf("%s usage:\n",progname);
printf("Example: %s -h ${brokeraddress} -p ${brokerport} -i ${clientid} -u ${username} -p ${password} -t${topic} -h ${help} -d ${daemon}\n",progname);
printf("-h(--host): sepcify brokeraddress.\n");
printf("-p(--port): sepcify brokerport.\n");
printf("-h(--Help): print this help information.\n");
printf("-d(--daemon): set program running on background.\n");
printf("-i(--clientid): sepcify the clientid.\n");
printf("-u(--username): sepcify username of the client.\n");
printf("-p(--password): sepcify password of the username.\n");
printf("-t(--topic): sepcify topic of the client.\n");
printf("-d(--daemon): running in backgrund.\n");
}
void connect_callback(struct mosquitto *mosq,void *obj,int rc)
{
char ipaddr[16];
char *interface="eth0";
char datetime[64];
cJSON *root;
cJSON *item;
char *msg;
struct mqtt_user_data *mqtt;
char buf[2048];
printf("Connection successful cJSON call packaging\n");
float temper = 0.00000000;
if(get_temperature(&temper) < 0)
{
printf("get_temperature failed.\n");
return;
}
if(get_time(datetime,sizeof(datetime))<0)
{
printf("get_time failure\n");
return ;
}
memset(ipaddr,0,sizeof(ipaddr));
if(get_ipaddr(interface,ipaddr,sizeof(ipaddr))<0)
{
printf("ERROR:get ip address failure\n");
return ;
}
snprintf(buf,sizeof(buf),"%s/%s/%f",ipaddr,datetime,temper);
sqlite_tem(buf);
printf("Data transfer database successfully!\n");
printf("\n");
root = cJSON_CreateObject();
item = cJSON_CreateObject();
if(!obj)
{
printf("invalid_argument in %s\n",__FUNCTION__);
return;
}
mqtt = (mqtt_user_data *)obj;
cJSON_AddItemToObject(root,"method",cJSON_CreateString(mqtt->method));
cJSON_AddItemToObject(root,"id",cJSON_CreateString(ipaddr));
cJSON_AddItemToObject(root,"time",cJSON_CreateString(datetime));
cJSON_AddItemToObject(root,"params",item);
cJSON_AddItemToObject(item,"CurrentTemperature",cJSON_CreateNumber(temper));
cJSON_AddItemToObject(root,"version",cJSON_CreateString(mqtt->version));
msg = cJSON_Print(root);
printf("%s\n",msg);
if(!rc)
{
if(mosquitto_publish(mosq,NULL,mqtt->topic,strlen(msg),msg,mqtt->Qos,NULL) != MOSQ_ERR_SUCCESS)
{
printf("mosquitto_publish failed: %s\n",strerror(errno));
return;
}
}
mosquitto_disconnect(mosq);
}
int get_temperature(float *temper)
{
char w1_path[64] = "/sys/bus/w1/devices/";
char chip[32];
char buf[128];
DIR *dirp;
struct dirent *direntp;
int fd = -1;
char *ptr;
int found = 0;
if( !temper )
{
return -1;
}
if((dirp = opendir(w1_path)) == NULL)
{
printf("Opendir '%s' error: %s\n", w1_path, strerror(errno));
return -2;
}
while((direntp = readdir(dirp)) != NULL)
{
if(strstr(direntp->d_name,"28-"))
{
strncpy(chip, direntp->d_name, sizeof(chip));
found = 1;
break;
}
}
closedir(dirp);
if( !found )
{
printf("Can not find ds18b20 in '%s'\n", w1_path);
return -3;
}
strncat(w1_path, chip, sizeof(w1_path)-strlen(w1_path));
strncat(w1_path, "/w1_slave", sizeof(w1_path)-strlen(w1_path));
if( (fd=open(w1_path, O_RDONLY)) < 0 )
{
printf("open %s error: %s\n", w1_path, strerror(errno));
return -4;
}
if(read(fd, buf, sizeof(buf)) < 0)
{
printf("read %s error: %s\n", w1_path, strerror(errno));
return -5;
}
ptr = strstr(buf, "t=");
if( !ptr )
{
printf("ERROR: Can not get temperature\n");
return -6;
}
*temper = atof(ptr+=2)/1000;
close(fd);
return 0;
}
int get_time(char *datime,int len)
{
time_t t;
struct tm *p;
time(&t);
p = gmtime(&t);
snprintf(datime, 32, "%d-%d-%d %d:%d:%d", 1900+p->tm_year,1+p->tm_mon, p->tm_mday, (p->tm_hour + 8), p->tm_min, p->tm_sec);
return 0 ;
}
运行结果
可以看到温度在实时更新(我设置睡眠时间短,所有没有显示,温度变化).
Original: https://www.cnblogs.com/Ye-Wei/p/16728604.html
Author: 西故黄鹤楼
Title: 【MQTT】在Linux使用MQTT上报温度到阿里云
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