【XR806開發(fā)板試用】通過http請(qǐng)求從心知天氣網(wǎng)獲取天氣預(yù)報(bào)信息

1. 開發(fā)環(huán)境搭建

本次評(píng)測(cè)開發(fā)環(huán)境搭建在windows11的WSL2的Ubuntu20.04中，
(1) 在WSL的Ubuntu20.04下安裝必要的工具的.

• 安裝git:

sudo apt-get install git

• 安裝gcc編譯器套件:

sudo apt-get install build-essential

• 安裝bear，該工具用來(lái)生成編譯數(shù)據(jù)庫(kù)文件：compile_commands.json，可以實(shí)現(xiàn)編輯代碼時(shí)智能提示和代碼跳轉(zhuǎn).

sudo apt-get install bear

• 安裝ncurses庫(kù),使用make menuconfig配置工程時(shí)依賴該庫(kù).
  sudo apt-get install libncurses5-dev

(2)安裝windows下必要的工具
我們編譯的固件要通過串口燒錄到XR806,由于WSL2下不能直接使用windows的串口，所以需要在windows下使用工具 usbipd共享串口給WSL2使用，

(3)搭建XR806編譯開發(fā)環(huán)境

需要注意的是文章中提供的編譯工具鏈gcc-arm-none-eabi-8-2019-q3-update下載鏈接無(wú)效，

2. 創(chuàng)建工程

我們?cè)诮K端中進(jìn)入工程跟目錄，按如下步驟來(lái)配置工程和編譯代碼生成鏡像:

# 復(fù)制默認(rèn)配置文件到頂層目錄（不切換工程可不要此步驟）
$ make PRJ=demo/wifi_sta defconfig
# 檢查SDK 基礎(chǔ)配置，如工程名、芯片型號(hào)、高頻晶振、板級(jí)配置是否正確
$ make menuconfig
# 清理，切換工程時(shí)需要
$ make build_clean
# 編譯代碼并生成鏡像文件，生成的鏡像文件為“out/xr_system.img”
$ bear make build -j 12

依次執(zhí)行上述命令后，在工程根目錄執(zhí)行如下命令，使用vscode打開工程
code .
在vscode中打開工程目錄后，敲擊F1鍵，彈出如下選擇項(xiàng)，我們選擇C/C++:編輯配置(UI)

在編譯器路徑輸入框中輸入XR806交叉編譯器完整路徑，如下圖所示:

在高級(jí)設(shè)置下的編譯命令輸入框中輸入編譯數(shù)據(jù)庫(kù)文件compile_commands.json的路徑，如下圖所示：

3. 編輯工程代碼

想要從心知天氣網(wǎng)獲取天氣預(yù)報(bào)，首先需要注冊(cè)該網(wǎng)站賬號(hào). 注冊(cè)賬號(hào)并登陸，打開獲取天氣預(yù)報(bào)相關(guān)的API文檔頁(yè)
其中參數(shù)"your_api_key"是你獲取天氣預(yù)報(bào)信息的API密鑰，該API密鑰可以從心知天氣網(wǎng)主頁(yè)進(jìn)入控制臺(tái)頁(yè)面，然后點(diǎn)擊左側(cè)的"免費(fèi)版",即可看到自己的私鑰，該私鑰即為API 密鑰,如下圖所示:

接下來(lái)我們編寫代碼實(shí)現(xiàn)通過http請(qǐng)求從心知天氣網(wǎng)獲取未來(lái)3天的天氣信息.

1. 首先在main.c中添加必要的頭文件:

   #include < stdio.h >
   #include < string.h >
   #include "kernel/os/os.h"
   #include "net/wlan/wlan.h"
   #include "net/wlan/wlan_defs.h"
   #include "common/framework/net_ctrl.h"
   #include "common/framework/platform_init.h"
   
   #include < errno.h >
   #include "lwip/err.h"
   #include "lwip/sockets.h"
   #include "lwip/sys.h"
   #include "lwip/inet.h"
   #include "lwip/netdb.h"
   #include "sys/select.h"
   
   #include "cjson/cJSON.h"
   

2. 然后定義關(guān)于天氣信息的結(jié)構(gòu)體類型:

   /* 天氣數(shù)據(jù)結(jié)構(gòu)體 */
   typedef struct tagWeather
   {
    /* 實(shí)況天氣數(shù)據(jù) */
    char id[32];                //id
    char name[32];                //地名
    char country[32];            //國(guó)家
    char path[32];                //完整地名路徑
    char timezone[32];            //時(shí)區(qū)
    char timezone_offset[32];   //時(shí)差
    char text[32];                //天氣預(yù)報(bào)文字
    char code[32];                //天氣預(yù)報(bào)代碼
    char temperature[32];       //氣溫
    char last_update[32];        //最后一次更新的時(shí)間
   
   
    /* 今天、明天、后天天氣數(shù)據(jù) */
    char date[3][32];            //日期
    char text_day[3][64];        //白天天氣現(xiàn)象文字
    char code_day[3][32];        //白天天氣現(xiàn)象代碼
    char code_night[3][64];     //晚間天氣現(xiàn)象代碼
    char high[3][32];            //最高溫
    char low[3][32];            //最低溫
    char wind_direction[3][64]; //風(fēng)向
    char wind_speed[3][32];      //風(fēng)速，單位km/h（當(dāng)unit=c時(shí)）
    char wind_scale[3][32];      //風(fēng)力等級(jí)
   } Weather_T;
   

3. 再定義通過http的GET請(qǐng)求方式獲取天氣預(yù)報(bào)的請(qǐng)求頭部:

   #define WEB_SERVER     "api.seniverse.com" // 天氣預(yù)報(bào)網(wǎng)服務(wù)器地址
   #define WEB_PORT       "80"                // 天氣預(yù)報(bào)網(wǎng)服務(wù)器端口號(hào)
   #define CONFIG_API_KEY "xxxxxxxxxxxxxx" // 你的API密鑰,從心知天氣網(wǎng)控制臺(tái)頁(yè)面獲取
   /* 獲取天氣預(yù)報(bào)信息的http請(qǐng)求頭部 */
   #define  GET_REQUEST_PACKAGE     
         "GET https://api.seniverse.com/v3/weather/daily.json?key=" CONFIG_API_KEY "&location=%s&language=zh-Hans&unit=crnrn"
   
   #define HTTPC_DEMO_THREAD_STACK_SIZE (8 * 1024) /* 任務(wù)棧大小 */
   

4. 定義WiFi的ssid和password:

   char *sta_ssid = "xxxxxx";  // 你要連接的WiFi名
   char *sta_psk = "xxxxxxxx"; // 你要連接的WiFi密碼
   char httpc_response_buf[2048]; //用于保存獲取到的天氣信息的原始數(shù)據(jù)
   int write_idx = 0;  // 寫數(shù)據(jù)到httpc_response_buf的數(shù)組下標(biāo)
   static OS_Thread_t httpc_demo_thread; // 獲取天氣的線程ID
   

5. 編寫WiFi聯(lián)網(wǎng)初始化函數(shù):

   void sta_start(void)
   {
    /* switch to sta mode */
    net_switch_mode(WLAN_MODE_STA);
   
   #if STA_MODE_USE_WPA2_ONLY
    /* set ssid and password to wlan, only use WPA2 mode to connect AP. */
    wlan_sta_config((uint8_t *)sta_ssid, strlen(sta_ssid), (uint8_t *)sta_psk, 0);
   #else
    /* set ssid and password to wlan, use WPA2|WPA3 compatible mode to connect AP. */
    wlan_sta_set((uint8_t *)sta_ssid, strlen(sta_ssid), (uint8_t *)sta_psk);
   #endif
   
    /* start scan and connect to ap automatically */
    wlan_sta_enable();
   }
   

6. 在mian函數(shù)中添加如下代碼

   int main(void)
   {
    observer_base *net_ob;
   
    platform_init();
   
    /* create an observer to monitor the net work state */
    net_ob = sys_callback_observer_create(CTRL_MSG_TYPE_NETWORK,
                                         NET_CTRL_MSG_ALL,
                                         net_cb,
                                         NULL);
    if (net_ob == NULL) {
        return -1;
    }
   
    if (sys_ctrl_attach(net_ob) != 0) {
        return -1;
    }
   
    sta_start();
   
    return 0;
   }
   

   其中，函數(shù)sys_callback_observer_create創(chuàng)建一個(gè)事件監(jiān)聽器，當(dāng)函數(shù)第1個(gè)參數(shù)CTRL_MSG_TYPE_NETWORK和第2個(gè)參數(shù)NET_CTRL_MSG_ALL所指定的事件發(fā)生時(shí)自動(dòng)調(diào)用回調(diào)函數(shù)net_cb，此處表示所有的網(wǎng)絡(luò)事件發(fā)生時(shí)均會(huì)調(diào)用回調(diào)函數(shù)net_cb，net_cb定義如下:

   static void net_cb(uint32_t event, uint32_t data, void *arg)
   {
    uint16_t type = EVENT_SUBTYPE(event);
   
    switch (type) {
    case NET_CTRL_MSG_NETWORK_UP: // WiFi sta連接AP成功并自動(dòng)分配了ip地址
        {
        /* 打印本機(jī)的IP地址,網(wǎng)關(guān)，子網(wǎng)掩碼 */
            struct netif *nif = wlan_netif_get(WLAN_MODE_STA);
            while (!NET_IS_IP4_VALID(nif)) {
                OS_MSleep(100);
            }
   
            printf("local ip: %sn", ipaddr_ntoa(&nif- >ip_addr));
            printf("gw: %sn", ipaddr_ntoa(&nif- >gw));
            printf("netmask: %sn", ipaddr_ntoa(&nif- >netmask));
        }
        /*創(chuàng)建線程，通過http請(qǐng)求獲取天氣預(yù)報(bào)信息*/
        if (!OS_ThreadIsValid(&httpc_demo_thread)) {
            OS_ThreadCreate(&httpc_demo_thread,
                                "httpc_demo_thread",
                                httpc_demo_fun,
                                (void *)NULL,
                                OS_THREAD_PRIO_APP,
                                HTTPC_DEMO_THREAD_STACK_SIZE);
        }
        break;
   
    case NET_CTRL_MSG_NETWORK_DOWN: //WiFi連接斷開事件
        break;
   
    default:
        break;
    }
   }
   

   httpc_demo_fun函數(shù)的定義如下:

   static void httpc_demo_fun(void *arg)
   {
    http_get_weather("beijing");
    // 獲取天氣預(yù)報(bào)信息結(jié)束后，刪除本線程
    OS_ThreadDelete(&httpc_demo_thread);
   }
   

   其中http_get_weather函數(shù)的參數(shù)即為想要獲取天氣預(yù)報(bào)的城市的漢語(yǔ)拼音名，定義如下:

   static void http_get_weather(char *city)
   {
    int32_t ret;
    char request_head[sizeof(REQUEST) + 64];
    const struct addrinfo hints = {
        .ai_family = AF_INET,
        .ai_socktype = SOCK_STREAM,
    };
    struct addrinfo *res;
    struct in_addr *addr;
    int s, r;
    Weather_T weather_data = {0};
   
    bzero(httpc_response_buf, sizeof(httpc_response_buf));
    /* 通過服務(wù)器域名和端口獲取服務(wù)器的IP地址相關(guān)信息 */
    ret = getaddrinfo(WEB_SERVER, WEB_PORT, &hints, &res);
    if (ret != 0 || res == NULL) {
        printf("DNS lookup failed ret=%d res=%pn", ret, res);
        return;
    }
    // Note: inet_ntoa is non-reentrant, look at ipaddr_ntoa_r for "real" code */
    addr = &((struct sockaddr_in *)res- >ai_addr)- >sin_addr;
    printf("DNS lookup succeeded. IP=%sn", inet_ntoa(*addr));
   
    /* 創(chuàng)建soocket */
    s = socket(res- >ai_family, res- >ai_socktype, 0);
    if(s < 0) {
        printf("... Failed to allocate socket.n");
        freeaddrinfo(res);
        return;
    }
    printf("... allocated socketn");
   
    /* 使用第1步獲取的服務(wù)器IP地址連接服務(wù)器 */
    if(connect(s, res- >ai_addr, res- >ai_addrlen) != 0) {
        printf("... socket connect failed errno=%dn", errno);
        close(s);
        freeaddrinfo(res);
        return;
    }
   
    printf("... connectedn");
    freeaddrinfo(res);
   
    /* 使用城市名生成完整的http的GET請(qǐng)求頭部并發(fā)送到服務(wù)器*/
    snprintf(request_head, sizeof(request_head), GET_REQUEST_PACKAGE, city);
    if (write(s, request_head, strlen(request_head)) < 0) {
        printf("... socket send failedn");
        close(s);
        return;
    }
    printf("... socket send successn");
   
    /* 讀取服務(wù)器返回的應(yīng)答數(shù)據(jù) */
    /* Read HTTP response */
    do {
        r = read(s, &httpc_response_buf[write_idx], sizeof(httpc_response_buf) - write_idx -1);
        if (r > 0) {
            write_idx += r;
        }
    } while(r > 0 && write_idx < (sizeof(httpc_response_buf) - 1));
   
    printf("... done reading from socket. Last read return=%d write_idx=%u errno=%d.n", r, write_idx, errno);
    /* 打印服務(wù)器返回的數(shù)據(jù) */
    for    (int i = 0; i < write_idx; ++i) {
        putchar(httpc_response_buf[i]);
    }
    puts("");
    /* 解析天氣預(yù)報(bào)數(shù)據(jù) */
    ret = cJSON_DailyWeatherParse(httpc_response_buf, &weather_data);
    if (ret == 0) {
    /* 格式化打印天氣預(yù)報(bào)信息 */
        DisplayWeather(&weather_data);
    }
    close(s);
   }
   

   由于服務(wù)器返回的天氣預(yù)報(bào)數(shù)據(jù)為json字符串, 我們編寫函數(shù)cJSON_DailyWeatherParse解析天氣預(yù)報(bào)json數(shù)據(jù)并保存到結(jié)構(gòu)體變量weather_data中，cJSON_DailyWeatherParse函數(shù)和DisplayWeather函數(shù)的定義如下:

   static int cJSON_DailyWeatherParse(char *JSON, Weather_T *result)
   {
    cJSON *json,*arrayItem,*object,*subobject,*item,*sub_child_object,*child_Item;
   
    json = cJSON_Parse(JSON); //解析JSON數(shù)據(jù)包
    if(json == NULL)          //檢測(cè)JSON數(shù)據(jù)包是否存在語(yǔ)法上的錯(cuò)誤，返回NULL表示數(shù)據(jù)包無(wú)效
    {
        printf("Error before: [%s]n",cJSON_GetErrorPtr()); //打印數(shù)據(jù)包語(yǔ)法錯(cuò)誤的位置
        return 1;
    }
    else
    {
        if ((arrayItem = cJSON_GetObjectItem(json,"results")) != NULL) //匹配字符串"results",獲取數(shù)組內(nèi)容
        {
            // int size = cJSON_GetArraySize(arrayItem);     //獲取數(shù)組中對(duì)象個(gè)數(shù)
   #if DEBUG
            printf("Get Array Size: size=%dn",size);
   #endif
            if((object = cJSON_GetArrayItem(arrayItem,0)) != NULL)//獲取父對(duì)象內(nèi)容
            {
                /* 匹配子對(duì)象1------結(jié)構(gòu)體location */
                if((subobject = cJSON_GetObjectItem(object,"location")) != NULL)
                {
                    if((item = cJSON_GetObjectItem(subobject,"name")) != NULL) //匹配子對(duì)象1成員"name"
                    {
                        memcpy(result- >name, item- >valuestring,strlen(item- >valuestring));         // 保存數(shù)據(jù)供外部調(diào)用
                    }
                }
                /* 匹配子對(duì)象2------數(shù)組daily */
                if((subobject = cJSON_GetObjectItem(object,"daily")) != NULL)
                {
                    int sub_array_size = cJSON_GetArraySize(subobject);
   #if DEBUG
                    printf("Get Sub Array Size: sub_array_size=%dn",sub_array_size);
   #endif
                    for(int i = 0; i < sub_array_size; i++)
                    {
                        if((sub_child_object = cJSON_GetArrayItem(subobject,i))!=NULL)
                        {
                            // 匹配日期
                            if((child_Item = cJSON_GetObjectItem(sub_child_object,"date")) != NULL)
                            {
                                memcpy(result- >date[i], child_Item- >valuestring,strlen(child_Item- >valuestring));         // 保存數(shù)據(jù)
                            }
                            // 匹配白天天氣現(xiàn)象文字
                            if((child_Item = cJSON_GetObjectItem(sub_child_object,"text_day")) != NULL)
                            {
                                memcpy(result- >text_day[i], child_Item- >valuestring,strlen(child_Item- >valuestring));     // 保存數(shù)據(jù)
                            }
                            // 匹配白天天氣現(xiàn)象代碼
                            if((child_Item = cJSON_GetObjectItem(sub_child_object,"code_day")) != NULL)
                            {
                                memcpy(result- >code_day[i], child_Item- >valuestring,strlen(child_Item- >valuestring));     // 保存數(shù)據(jù)
                            }
                            // 匹配夜間天氣現(xiàn)象代碼
                            if((child_Item = cJSON_GetObjectItem(sub_child_object,"code_night")) != NULL)
                            {
                                memcpy(result- >code_night[i], child_Item- >valuestring,strlen(child_Item- >valuestring)); // 保存數(shù)據(jù)
                            }
                            // 匹配最高溫度
                            if((child_Item = cJSON_GetObjectItem(sub_child_object,"high")) != NULL)
                            {
                                memcpy(result- >high[i], child_Item- >valuestring,strlen(child_Item- >valuestring));         //保存數(shù)據(jù)
                            }
                            // 匹配最低溫度
                            if((child_Item = cJSON_GetObjectItem(sub_child_object,"low")) != NULL)
                            {
                                memcpy(result- >low[i], child_Item- >valuestring,strlen(child_Item- >valuestring));         // 保存數(shù)據(jù)
                            }
                            // 匹配風(fēng)向
                            if((child_Item = cJSON_GetObjectItem(sub_child_object,"wind_direction")) != NULL)
                            {
                                memcpy(result- >wind_direction[i],child_Item- >valuestring,strlen(child_Item- >valuestring)); //保存數(shù)據(jù)
                            }
                            // 匹配風(fēng)速，單位km/h（當(dāng)unit=c時(shí)）
                            if((child_Item = cJSON_GetObjectItem(sub_child_object,"wind_speed")) != NULL)
                            {
                                memcpy(result- >wind_speed[i], child_Item- >valuestring,strlen(child_Item- >valuestring)); // 保存數(shù)據(jù)
                            }
                            // 匹配風(fēng)力等級(jí)
                            if((child_Item = cJSON_GetObjectItem(sub_child_object,"wind_scale")) != NULL)
                            {
                                memcpy(result- >wind_scale[i], child_Item- >valuestring,strlen(child_Item- >valuestring)); // 保存數(shù)據(jù)
                            }
                        }
                    }
                }
                /* 匹配子對(duì)象3------最后一次更新的時(shí)間 */
                if((subobject = cJSON_GetObjectItem(object,"last_update")) != NULL)
                {
                    //printf("%s:%sn",subobject- >string,subobject- >valuestring);
                }
            }
        }
    }
    cJSON_Delete(json); //釋放cJSON_Parse()分配出來(lái)的內(nèi)存空間
   
    return 0;
   }
   
   /*******************************************************************************************************
   ** 函數(shù): DisplayWeather，顯示天氣數(shù)據(jù)
   **------------------------------------------------------------------------------------------------------
   ** 參數(shù): weather_data：天氣數(shù)據(jù)
   ** 返回: void
   ********************************************************************************************************/
   static void DisplayWeather(Weather_T *weather_data)
   {
    printf("===========%s近三天的天氣情況如下===========n",weather_data- >name);
    printf("【%s】n",weather_data- >date[0]);
    printf("天氣：%sn",weather_data- >text_day[0]);
    printf("最高溫：%s℃n",weather_data- >high[0]);
    printf("最低溫：%s℃n",weather_data- >low[0]);
    printf("風(fēng)向：%sn",weather_data- >wind_direction[0]);
    printf("風(fēng)速：%skm/hn",weather_data- >wind_speed[0]);
    printf("風(fēng)力等級(jí)：%sn",weather_data- >wind_scale[0]);
    printf("n");
    printf("【%s】n",weather_data- >date[1]);
    printf("天氣：%sn",weather_data- >text_day[1]);
    printf("最高溫：%s℃n",weather_data- >high[1]);
    printf("最低溫：%s℃n",weather_data- >low[1]);
    printf("風(fēng)向：%sn",weather_data- >wind_direction[1]);
    printf("風(fēng)速：%skm/hn",weather_data- >wind_speed[1]);
    printf("風(fēng)力等級(jí)：%sn",weather_data- >wind_scale[1]);
    printf("n");
    printf("【%s】n",weather_data- >date[2]);
    printf("天氣：%sn",weather_data- >text_day[2]);
    printf("最高溫：%s℃n",weather_data- >high[2]);
    printf("最低溫：%s℃n",weather_data- >low[2]);
    printf("風(fēng)向：%sn",weather_data- >wind_direction[2]);
    printf("風(fēng)速：%skm/hn",weather_data- >wind_speed[2]);
    printf("風(fēng)力等級(jí)：%sn",weather_data- >wind_scale[2]);
   }
   

7. 編譯工程
   bear make build -j 8

8. 燒錄鏡像到xr806
   首先使用USB線將開發(fā)板連上電腦，可能需要重新安裝CP2102驅(qū)動(dòng)，在Windows中打開powershell,輸入如下命令:

   PS C:Users30751Desktop > usbipd wsl list
   BUSID  VID:PID    DEVICE                                                        STATE
   2-1    10c4:ea60  Silicon Labs CP210x USB to UART Bridge (COM3)                 Not attached
   2-3    248a:8367  USB 輸入設(shè)備                                                  Not attached
   2-6    0c45:6a1b  Integrated Webcam                                             Not attached
   2-10   8087:0026  英特爾(R) 無(wú)線 Bluetooth(R)                                   Not attached
   

   我們可以看到開發(fā)板連接的USB端口的的BUSID為2-1，接著使用如下命令將該USB串口共享給WSL:

   PS C:Users30751Desktop > usbipd wsl attach --busid 2-1
   usbipd: info: Using default WSL distribution 'Ubuntu-20.04'; specify the '--distribution' option to select a different one.
   

   接下來(lái)我們?cè)赨buntu終端中進(jìn)入工程源碼目錄下的tools目錄下，開啟固件燒錄USB串口的讀寫權(quán)限:
   sudo chmod 666 /dev/ttyUSB0
   使用如下命令燒錄鏡像到xr806
   ./phoenixMC
   燒錄成功信息如下:

   

   我們?cè)俅卧赪indows中打開powershell,輸入如下命令將開發(fā)板連接到windows:
   usbipd wsl detach --busid 2-1
   我們?cè)趙indows中打開終端軟件Tera Term，連上開發(fā)板串口,復(fù)位開發(fā)板將會(huì)看到如下信息:

   use default flash chip mJedec 0x0
   [FD I]: mode: 0x10, freq: 96000000Hz, drv: 0
   [FD I]: jedec: 0x0, suspend_support: 1
   mode select:e
   
   wlan information ===================================================
   firmware:
    version : R0-XR_C07.08.52.67_ULP_R_02.132 Jan 10 2023 19:14:11-Y02.132
    buffer  : 8
   driver:
    version : XR_V02.06.10
   mac address:
    in use        : 8c:6d:08:3d:14:01
    in use        : 8c:6d:08:3d:14:02
   ====================================================================
   
   wlan mode:a
   
   platform information ===============================================
   XR806 SDK v1.2.2  Oct 21 2023 23:46:57 62800400
   
   heap space [0x217098, 0x24bc00), size 215912
   
   cpu  clock 160000000 Hz
   HF   clock  40000000 Hz
   
   sdk option:
    XIP           : enable
    INT LF OSC    : enable
    INT LDO       : select
    INT LDO / EXT PWR: enable
    SIP flash     : enable
   
   mac address:
    efuse         : 80:74:84:05:b9:ca
    in use        : 8c:6d:08:3d:14:01
   ====================================================================
   
   [net INF] no need to switch wlan mode 0
   [net INF] msg < wlan scan success >
   en1: Trying to associate with 8c:ab:8e:fd:c3:58 (SSID='302' freq=2412 MHz)
   en1: Associated with 8c:ab:8e:fd:c3:58
   en1: WPA: Key negotiation completed with 8c:ab:8e:fd:c3:58 [PTK=CCMP GTK=TKIP]
   en1: CTRL-EVENT-CONNECTED - Connection to 8c:ab:8e:fd:c3:58 completed [id=0 id_str=]
   [net INF] msg < wlan connected >
   [net INF] netif is link up
   [net INF] start DHCP...
   WAR drop=1135, fctl=0x00d0.
   [net INF] netif (IPv4) is up
   [net INF] address: 192.168.2.107
   [net INF] gateway: 192.168.2.1
   [net INF] netmask: 255.255.255.0
   [net INF] msg < network up >
   local ip: 192.168.2.107
   gw: 192.168.2.1
   netmask: 255.255.255.0
   DNS lookup succeeded. IP=116.62.81.138
   ... allocated socket
   ... connected
   ... socket send success
   ... done reading from socket. Last read return=0 write_idx=995 errno=107.
   {"results":[{"location":{"id":"WX4FBXXFKE4F","name":"北京","country":"CN","path":"北京,北京,中國(guó)","timezone":"Asia/Shanghai","timezone_offset":"+08:00"},"daily":[{"date":"2023-10-22","text_day":"晴","code_day":"0","text_night":"晴","code_night":"1","high":"21","low":"6","rainfall":"0.00","precip":"0.00","wind_direction":"無(wú)持續(xù)風(fēng)向","wind_direction_degree":"","wind_speed":"8.4","wind_scale":"2","humidity":"61"},{"date":"2023-10-23","text_day":"晴","code_day":"0","text_night":"晴","code_night":"1","high":"21","low":"7","rainfall":"0.00","precip":"0.00","wind_direction":"無(wú)持續(xù)風(fēng)向","wind_direction_degree":"","wind_speed":"3.0","wind_scale":"1","humidity":"75"},{"date":"2023-10-24","text_day":"晴","code_day":"0","text_night":"晴","code_night":"1","high":"23","low":"9","rainfall":"0.00","precip":"0.00","wind_direction":"無(wú)持續(xù)風(fēng)向","wind_direction_degree":"","wind_speed":"3.0","wind_scale":"1","humidity":"75"}],"last_update":"2023-10-20T08:00:00+08:00"}]}
   ===========北京近三天的天氣情況如下===========
   【2023-10-22】
   天氣：晴
   最高溫：21℃
   最低溫：6℃
   風(fēng)向：無(wú)持續(xù)風(fēng)向
   風(fēng)速：8.4km/h
   風(fēng)力等級(jí)：2
   
   【2023-10-23】
   天氣：晴
   最高溫：21℃
   最低溫：7℃
   風(fēng)向：無(wú)持續(xù)風(fēng)向
   風(fēng)速：3.0km/h
   風(fēng)力等級(jí)：1
   
   【2023-10-24】
   天氣：晴
   最高溫：23℃
   最低溫：9℃
   風(fēng)向：無(wú)持續(xù)風(fēng)向
   風(fēng)速：3.0km/h
   風(fēng)力等級(jí)：1
   

   可以看到我們已經(jīng)成功獲取了北京的未來(lái)三天的天氣情況.

   4. 總結(jié)

   通過本次開發(fā)板評(píng)測(cè)，掌握了XR806的WiFi相關(guān)API的使用，系統(tǒng)事件監(jiān)聽API的使用掌，握了sokect網(wǎng)絡(luò)編程相關(guān)知識(shí)，掌握了cJSON的使用.