NL6621 实现获取天气情况

本文主要是介绍NL6621 实现获取天气情况，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

一、主要完成的工作

1、建立TASK

INT32 main(VOID)
{/* system Init */SystemInit();OSTaskCreate(TestAppMain, NULL, &sAppStartTaskStack[NST_APP_START_TASK_STK_SIZE -1],  NST_APP_TASK_START_PRIO); OSStart();return 1;
}

2、application test task

VOID TestAppMain(VOID * pParam)
{demo_gpio_init();     //初始化LCD GPIOInitLCD();            //初始化屏幕clrScr(VGA_BLACK);    //清屏GUI_Write16CnCharMatrix(0,160,"初始化......     ",VGA_BLUE,VGA_BLACK);pLinkUpSem = OSSemCreate(0);InfSysEvtCBSet(AppEvtCallBack);InfLoadDefaultParam();sys_thread_new("weatherThread", weatherThread, NULL, NST_TEST_APP_TASK_STK_SIZE, TCPIP_THREAD_PRIO + 4);while (1) {                                          /* Task body, always written as an infinite loop.       */OSTimeDly(20);DBGPRINT_LWIP(DEBUG_INFO, "TestApp RxDataCnt=%d, SendDataCnt=%d.\n", RxDataCnt, SendDataCnt);}}

**3、void weatherThread(void *arg)**

void weatherThread(void *arg)
{char* buff,*http_data;DBGPRINT(DEBUG_TRACE, " ********************** weatherThread ********************* \n\r");connectWifi();            //连接WIFIbuff=TestWeatherApi();    //从网页API获得天气数据printf("%s\r\n", buff);http_data=https_get_data(buff);    //获得JSON部分mem_free(buff);printf("[http_data]:%s\r\n", http_data);extract_all_from_json(http_data);    //解析JSON数据mem_free(http_data);//LCD显示GUI_Write16CnCharMatrix(5,20,"日期：",VGA_WHITE,VGA_BLACK);GUI_Write16CnCharMatrix(53,20,city_weather.date,VGA_BLUE,VGA_BLACK);GUI_Write16CnCharMatrix(5,60,"城市：",VGA_WHITE,VGA_BLACK);GUI_Write16CnCharMatrix(53,60,city_weather.city,VGA_BLUE,VGA_BLACK);GUI_Write16CnCharMatrix(5,100,"温度：",VGA_WHITE,VGA_BLACK);GUI_Write16CnCharMatrix(53,100,city_weather.tem,VGA_BLUE,VGA_BLACK);while(1){OSTimeDly(500);}
}

4、void connectWifi(void)

void connectWifi(void)
{UINT8 Err;InfWiFiStop();OSTimeDly(10);InfNetModeSet(PARAM_NET_MODE_STA_BSS); InfAuthModeSet(PARAM_AUTH_MODE_WPA2PSK);//此处根据实际修改SSID/PASSWORDInfSsidSet("SSID",4);    /* set ssid */InfKeySet(0, "PASSWORD",8);  /* set pw */InfEncModeSet(PARAM_ENC_MODE_AUTO);InfConTryTimesSet(0);                       /* set trytime */	InfWiFiStart();//Waiting for connect successOSSemPend(pLinkUpSem, 0, &Err);
}

5、char* TestWeatherApi(void)

#define HTTP_HOST "v1.yiketianqi.com"
#define HTTP_URL  "api?unescape=1&version=v61&appid=此处替换自己的ID&appsecret=此处替换自己的key"
#define HOST_PORT "80"
static const char* REQUEST = "GET " "/%s" " HTTP/1.1\r\n"
"Host: " "%s" ":" HOST_PORT "\r\n"
"User-Agent: AiPi-DSL_Dashboard\r\n"
"\r\n";char*  TestWeatherApi(void)
{char* https_request_handle = mem_malloc(512);char *recv_data;int sock; UINT32 TargetIp;struct sockaddr_in server_addr;ip_addr_t hostip;netconn_gethostbyname(HTTP_HOST, &hostip);DBGPRINT_LWIP(DEBUG_TRACE, "HTTP_HOST:%s,IP:%d\n",HTTP_HOST,hostip.addr);TargetIp =hostip.addr;DBGPRINT_LWIP(DEBUG_TRACE, "TargetIp:%d\n",TargetIp);/* 分配用于存放接收数据的缓冲 */recv_data = mem_malloc(1024*4);if (recv_data == NULL){DBGPRINT_LWIP(DEBUG_ERROR, "TCP Client  memory ERR\n");return 0;}/* 一、创建一个socket，类型是SOCKET_STREAM，TCP类型 */if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1){/* 创建socket失败 */DBGPRINT_LWIP(DEBUG_ERROR, "TCP Client Socket error\n");/* 释放接收缓冲 */mem_free(recv_data);return 0;}/* 初始化预连接的服务端地址 */server_addr.sin_family = AF_INET;server_addr.sin_port = htons(atoi(HOST_PORT)); server_addr.sin_addr.s_addr= TargetIp;memset(&(server_addr.sin_zero), 0, sizeof(server_addr.sin_zero));/* 二、连接到服务端 */if (connect(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) == -1){/* 连接失败 */DBGPRINT_LWIP(DEBUG_TRACE, "TCP Client connect error !");lwip_close(sock);///*释放接收缓冲 */mem_free(recv_data);return 0;//OSTimeDly(2000);}else{DBGPRINT_LWIP(DEBUG_TRACE, "TCP Client connect OK!\n");}memset(https_request_handle, 0, 256);sprintf(https_request_handle, REQUEST, HTTP_URL, HTTP_HOST);/* 三、http请求 */if(write(sock, https_request_handle, strlen(https_request_handle))<0){DBGPRINT_LWIP(DEBUG_TRACE, "http write error !");close(sock);}/* 四、读http返回结果 */read(sock, recv_data, 1024*4);shutdown(sock, SHUT_RDWR);close(sock);mem_free(https_request_handle);return recv_data;
}

**6、static char* https_get_data(const char* https_request_data)**


static char* https_get_data(const char* https_request_data)
{char* request_data = https_request_data;static char* https_data;char* request_value;size_t i;https_data = mem_malloc(1024*3);memset(https_data, 0, 1024*3);request_data += 2;request_value = strtok(request_data, "\n");for (i = 0; i < 15; i++){if (i==14) strcpy(https_data, request_value);memset(request_value, 0, strlen(request_value));request_value = strtok(NULL, "\n");}return https_data;
}

7、json解析

void extract_item_from_json(const char *json_str,char *itemname,char *target)
{char *start = strstr(json_str, itemname); // 查找"cityEn":"  char *end;size_t len=20;char item[20]; // +1 for null terminatorif (start != NULL) {  start += strlen(itemname); // 跳过itemname end = strchr(start, '"'); // 查找下一个双引号  if (end != NULL) {  // 提取  len = end - start;  strncpy(item, start, len);  item[len] = '\0'; // 添加字符串结束符  printf("Item: %s\n", item);  strncpy(target, item, len);target[len] = '\0'; // 添加字符串结束符 }  } else {  printf("Item[%s] not found in the JSON string.\n",itemname);  }  
}void extract_all_from_json(const char *json_str)
{extract_item_from_json(json_str,"\"cityEn\":\"",city_weather.city);extract_item_from_json(json_str,"\"tem\":\"",city_weather.tem);extract_item_from_json(json_str,"\"date\":\"",city_weather.date);
}

二、说明

1、NL6621 SDK二次开发，还是用KEIL4吧，KEIL5编译太慢了。

2、没用CJSON，不是不想用，尝试了好长时间还是用不了CJSON，最后JSON自己解析了。

3、编译的bin文件，不要超过192k，否则没法烧录，编译也会失败。

4、scatter_loader.scat没有为适应NuDevTool ver1.11.0.exe修改，需要用bootTool.exe或bootTool_Ack_0822.exe烧录。


; 0x10100-0x40000 for download SRAM FW(including 32KB for customer), interrupt vector locate in 0x10100
LOAD_REGION 0x00010100 0x0002FF00  {    ; load region size_regionROM  0x00010100 0x0002FF00  {  ; load address = execution address*.o (RESET, +First)    ; interrupt vector table, do not change it*(InRoot$$Sections).ANY (+RO)}

5、需要用NuDevTool ver1.11.0.exe烧录工具将字库gb2312_80.bin烧录到0xB0000，不烧录字库运行不了。