Esp8266学习之旅⑤ 8266原生乐鑫SDK高级使用之封装Post与Get请求云端，拿到“天气预报信息”。(带Demo)

一、前言。

1.1、 由于本篇博文理论多于代码，大家要耐心看下去哦。先上效果图：

1.2、我还是复制过来吧，图片看的模糊：

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----- PB  start -----
api.seniverse.com/v3/weather/daily.json?key=rrpd2zmqkpwlsckt&location=guangzhou&language=en&unit=c&start=0&days=3
----- PB next -----
/v3/weather/daily.json?key=rrpd2zmqkpwlsckt&location=guangzhou&language=en&unit=c&start=0&days=3
----- PB end -----

----- PB=true -----
api.seniverse.com

----- 请求数据开始-----
GET /v3/weather/daily.json?key=rrpd2zmqkpwlsckt&location=guangzhou&language=en&unit=c&start=0&days=3 HTTP/1.1
Content-Type: text/html;charset=utf-8
Accept: */*
Host: api.seniverse.com
Connection: Keep-Alive

-----请求数据结束-----

发送数据成功！

----- 开始接受数据-----

HTTP/1.1 200 OK
Date: Tue, 28 Nov 2017 08:23:45 GMT
Content-Type: application/json; charset=utf-8
Content-Length: 900
Connection: keep-alive
Cache-Control: no-cache
Pragma: no-cache
Expires: -1

{"results":[{"location":{"id":"WS0E9D8WN298","name":"Guangzhou","country":"CN","path":"Guangzhou,Guangzhou,Guangdong,China","timezone":"Asia/Shanghai","timezone_offset":"+08:00"},"daily":[{"date":"2017-11-28","text_day":"Cloudy","code_day":"4","text_night":"Overcast","code_night":"9","high":"25","low":"18","precip":"","wind_direction":"CLM","wind_direction_degree":"","wind_speed":"10","wind_scale":"2"},{"date":"2017-11-29","text_day":"Overcast","code_day":"9","text_night":"Light rain","code_night":"13","high":"25","low":"16","precip":"","wind_direction":"CLM","wind_direction_degree":"","wind_speed":"10","wind_scale":"2"},{"date":"2017-11-30","text_day":"Light rain","code_day":"13","text_night":"Light rain","code_night":"13","high":"21","low":"14","precip":"","wind_direction":"CLM","wind_direction_degree":"","wind_speed":"10","wind_scale":"2"}],"last_update":"2017-11-28T11:00:00+08:00"}]}

-----结束接受数据-----

断开连接成功！

1.3、电路图：最小系统就行。因为不需要物理按键触发配网：

二、理论知识 。

2.1 、 esp8266从联网到云端取数据的原理。

2.2 、原理流程大概都懂了。但是重要的是搞硬件的电子爱好者可能不懂 啥是Post请求和Get请求，好吧！我再画一个图：

2.3 、既然请求方式都懂了，那么我们的8266是怎么做到请求数据呢？好吧！我再再画一个图：

三、上代码！

3.1 写头文件 my_http.h”的实现C文件。用于剖析URL，定义post请求或get请求。

#include "my_http.h"
#include "c_types.h"
#include "client.h"

//剖析URL
void ICACHE_FLASH_ATTR http_parse_request_url(char *URL, char *host,char *filename, unsigned short *port) {

char *PA;
char *PB;

memset(host, 0, sizeof(host));
memset(filename, 0, sizeof(filename));

*port = 0;

if (!(*URL)){
uart0_sendStr("\r\n ----- URL return -----  \r\n");
return;
}

PA = URL;
if (!strncmp(PA, "http://", strlen("http://"))) {
PA = URL + strlen("http://");
} else if (!strncmp(PA, "https://", strlen("https://"))) {
PA = URL + strlen("https://");
}

PB = strchr(PA, '/');
if (PB) {
uart0_sendStr("\r\n ----- PB=true -----  \r\n");
memcpy(host, PA, strlen(PA) - strlen(PB));
if (PB + 1) {
memcpy(filename, PB + 1, strlen(PB - 1));
filename[strlen(PB) - 1] = 0;
}
host[strlen(PA) - strlen(PB)] = 0;

uart0_sendStr(host,strlen(host));

} else {
uart0_sendStr("\r\n ----- PB=false -----  \r\n");
memcpy(host, PA, strlen(PA));
host[strlen(PA)] = 0;
uart0_sendStr(host,strlen(host));
}
PA = strchr(host, ':');
if (PA){
*port = atoi(PA + 1);
}else{
*port = 80;
}
}

//寻找DNS解析，并且配置
void ICACHE_FLASH_ATTR user_esp_dns_found(const char *name, ip_addr_t *ipaddr,void *arg) {

struct ip_info info;
wifi_get_ip_info(STATION_IF, &info);
my_station_init(ipaddr, &info.ip, port);

}

//定义Get请求的实现
void ICACHE_FLASH_ATTR startHttpQuestByGET(char *URL){
struct ip_addr addr;
memset(buffer,0,1024);
http_parse_request_url(URL,host,filename,&port);
os_sprintf(buffer,GET,filename,host);
espconn_gethostbyname(&user_tcp_conn,host, &addr,
user_esp_dns_found);
}

//定义Post请求的实现
void ICACHE_FLASH_ATTR startHttpQuestByPOST(char *URL,char *method,char *postdata){
struct ip_addr addr;
memset(buffer,0,1024);
http_parse_request_url(URL,host,filename,&port);
os_sprintf(buffer,POST,filename,strlen(postdata),host,postdata);
espconn_gethostbyname(&user_tcp_conn,host, &addr,
user_esp_dns_found);
}

3.2、写头文件client.h的实现C文件。用于配置本地端口、连接服务器

#include "client.h"
#include "iconv.h"
#include "stdio.h"
#include "string.h"

//成功接收到服务器返回数据函数
void ICACHE_FLASH_ATTR user_tcp_recv_cb(void *arg, char *pdata,
unsigned short len) {
uart0_sendStr("\r\n ----- 开始接受数据----- \r\n ");
uart0_tx_buffer(pdata, strlen(pdata));
uart0_sendStr("\r\n -----结束接受数据-----  \r\n ");

}

//发送数据到服务器成功的回调函数
void ICACHE_FLASH_ATTR user_tcp_sent_cb(void *arg) {
uart0_sendStr("发送数据成功！\r\n ");
}

//断开服务器成功的回调函数
void ICACHE_FLASH_ATTR user_tcp_discon_cb(void *arg) {
uart0_sendStr("断开连接成功！\r\n ");
}

//连接失败的回调函数，err为错误代码
void ICACHE_FLASH_ATTR user_tcp_recon_cb(void *arg, sint8 err) {
uart0_sendStr("连接错误，错误代码为%d\r\n", err);
espconn_connect((struct espconn *) arg);
}

//成功连接到服务器的回调函数
void ICACHE_FLASH_ATTR user_tcp_connect_cb(void *arg) {
struct espconn *pespconn = arg;
espconn_regist_recvcb(pespconn, user_tcp_recv_cb);
espconn_regist_sentcb(pespconn, user_tcp_sent_cb);
espconn_regist_disconcb(pespconn, user_tcp_discon_cb);

uart0_sendStr("\r\n ----- 请求数据开始----- \r\n");
uart0_tx_buffer(buffer, strlen(buffer));
uart0_sendStr("\r\n -----请求数据结束-----  \r\n");

espconn_sent(pespconn, buffer, strlen(buffer));

}
void ICACHE_FLASH_ATTR my_station_init(struct ip_addr *remote_ip,
struct ip_addr *local_ip, int remote_port) {
//配置
user_tcp_conn.type = ESPCONN_TCP;
user_tcp_conn.state = ESPCONN_NONE;
user_tcp_conn.proto.tcp = (esp_tcp *) os_zalloc(sizeof(esp_tcp));
os_memcpy(user_tcp_conn.proto.tcp->local_ip, local_ip, 4);
os_memcpy(user_tcp_conn.proto.tcp->remote_ip, remote_ip, 4);
user_tcp_conn.proto.tcp->local_port = espconn_port();
user_tcp_conn.proto.tcp->remote_port = remote_port;
//注册
espconn_regist_connectcb(&user_tcp_conn, user_tcp_connect_cb);
espconn_regist_reconcb(&user_tcp_conn, user_tcp_recon_cb);
//连接服务器
espconn_connect(&user_tcp_conn);
}

3.3 程序入口，user_main.c。

#include "driver/uart.h"
#include "user_main.h"

//连接路由器的定时器
os_timer_t checkTimer_wifistate;

void Check_WifiState(void) {
uint8 getState;
getState = wifi_station_get_connect_status();

//如果状态正确，证明已经成功连接到路由器
if (getState == STATION_GOT_IP) {

os_printf("WIFI连接成功！把连接路由器的定时器关闭！");
os_timer_disarm(&checkTimer_wifistate);
os_timer_disarm(&connect_timer);

uint8 status = wifi_station_get_connect_status();
if (status == STATION_GOT_IP) {
uart0_sendStr("WIFI连接成功！开始请求数据！");
startHttpQuestByGET(
"https://api.seniverse.com/v3/weather/daily.json?key=rrpd2zmqkpwlsckt&location=guangzhou&language=en&unit=c&start=0&days=3");
return;
}
}

}

void user_init() {

uart_init(57600, 57600);
wifi_set_opmode(0x01); //设置为STATION模式
struct station_config stationConf;
os_strcpy(stationConf.ssid, "TP-LINK_AliYun");    //改成你自己的   路由器的用户名
os_strcpy(stationConf.password, "aliyun_123456"); //改成你自己的   路由器的密码
wifi_station_set_config(&stationConf); //设置WiFi station接口配置，并保存到 flash
wifi_station_connect(); //连接路由器

os_timer_disarm(&checkTimer_wifistate); //取消定时器定时
os_timer_setfn(&checkTimer_wifistate, (os_timer_func_t *) Check_WifiState,
NULL); //设置定时器回调函数
os_timer_arm(&checkTimer_wifistate, 500, true); //启动定时器，单位：毫秒500

}

4、关于服务器的选择与怎么看接口使用。

4.1、这个我使用的是心知天气，不是卖广告，*不喜勿喷！！