rt-thread studio实时读取天气怎么写

以下是一个简单的示例代码，演示如何在 RT-Thread Studio 中实时读取天气信息并在 OLED 屏幕上显示：

#include <rtthread.h>
#include <rtdevice.h>
#include <finsh.h>
#include <stdlib.h>
#include <string.h>
#include <dfs_posix.h>
#include <dfs_file.h>
#include <dfs.h>
#include <shell.h>
#include <board.h>
#include <oled.h>
#include <httpclient.h>
#include <json-c/json.h>

#define WEATHER_API_KEY "your_api_key" // 替换成你的天气 API 密钥 
#define WEATHER_API_URL "http://api.openweathermap.org/data/2.5/weather?q=shenzhen,cn&appid=" WEATHER_API_KEY

static void get_weather_data(void)
{
    char url[256];
    char response[1024];
    struct httpclient_data httpclient;
    json_object *root, *weather, *main, *temp, *humidity;
    int temperature, weather_id, humidity_value;

    // 拼接 API 请求地址
    rt_snprintf(url, sizeof(url), WEATHER_API_URL);

    // 初始化 HTTP 客户端
    httpclient_data_init(&httpclient);
    httpclient_set_server_url(&httpclient, url);

    // 发送 HTTP 请求
    if (httpclient_get(&httpclient) != HTTPCLIENT_OK) {
        rt_kprintf("Failed to get weather data, error: %s\n", httpclient.errmsg);
        goto exit;
    }

    // 解析返回的 JSON 数据
    root = json_tokener_parse(response);
    if (json_object_get_type(root) != json_type_object) {
        rt_kprintf("Failed to parse weather data\n");
        goto exit;
    }

    // 提取温度、湿度、天气状况等信息
    if (!json_object_object_get_ex(root, "main", &main) ||
        !json_object_object_get_ex(main, "temp", &temp) ||
        !json_object_object_get_ex(main, "humidity", &humidity) ||
        !json_object_object_get_ex(root, "weather", &weather)) {
        rt_kprintf("Failed to extract weather data\n");
        goto exit;
    }

    temperature = (int)json_object_get_double(temp) - 273; // 温度单位为开尔文，转换为摄氏度
    humidity_value = (int)json_object_get_double(humidity);
    weather_id = (int)json_object_get_int(json_object_array_get_idx(weather, 0));

    // 在 OLED 屏幕上显示天气信息
    oled_clear();
    oled_set_pos(0, 0);
    oled_put_string("Temperature:");
    oled_put_int(temperature);
    oled_put_string("C");
    oled_set_pos(1, 0);
    oled_put_string("Humidity:");
    oled_put_int(humidity_value);
    oled_put_string("%");
    oled_update();

exit:
    httpclient_data_deinit(&httpclient);
    json_object_put(root);
}

static void get_weather_thread_entry(void* parameter)
{
    while (1) {
        get_weather_data();
        rt_thread_delay(30000); // 每 30 秒更新一次天气数据
    }
}

int get_weather(void)
{
    rt_thread_t tid;
    tid = rt_thread_create("weather", get_weather_thread_entry, RT_NULL, 2048, 25, 5);
    if (tid != RT_NULL) {
        rt_thread_startup(tid);
        return 0;
    } else {
        return -1;
    }
}

// 在 RT-Thread Studio 命令行中输入 get_weather 命令即可启动天气获取线程
MSH_CMD_EXPORT(get_weather, get weather data);

在这个示例代码中，我们首先通过 HTTP 请求访问天气 API 获取天气数据，然后解析返回的 JSON 数据，提取需要的温度、湿度、天气状况等信息。最后使用 OLED 屏幕在 RT-Thread Studio 中显示天气信息，并使用一个线程每 30 秒更新一次天气数据。