rt-thread studio实时读取天气并显示在串口屏上

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串口屏上显示：

#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 <stdio.h>
#include <httpclient.h>
#include <json-c/json.h>
#include "bsp.h"
#include "serial_lcd.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

#define LCD_UART_NAME "uart2"
#define LCD_BAUDRATE 9600

static struct rt_serial_device lcd_serial;
static struct serial_lcd lcd;

static void lcd_init(void)
{
    rt_err_t result;
    struct serial_configure config = RT_SERIAL_CONFIG_DEFAULT;

    config.baud_rate = LCD_BAUDRATE;
    config.data_bits = DATA_BITS_8;
    config.stop_bits = STOP_BITS_1;
    config.parity = PARITY_NONE;

    rt_memset(&lcd_serial, 0, sizeof(lcd_serial));
    rt_memset(&lcd, 0, sizeof(lcd));

    lcd_serial.ops = &uart_ops;
    result = rt_serial_register(&lcd_serial, LCD_UART_NAME, &config, &lcd);
    if (result != RT_EOK) {
        rt_kprintf("Failed to register serial device for LCD, error: %d\n", result);
        return;
    }

    serial_lcd_init(&lcd);
}

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;
    char buffer[64];

    // 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));

    // 在串口屏上显示天气信息
    rt_snprintf(buffer, sizeof(buffer), "Temperature: %dC\nHumidity: %d%%\n", temperature, humidity_value);
    serial_lcd_clear(&lcd);
    serial_lcd_puts(&lcd, buffer);

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;
    rt_err_t result;

    lcd_init();

    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，我们首先在串口屏上初始化 LCD 并通过 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、湿度等信息。最后使用串口屏显示天气信息，并使用一个线程每 30 秒更新一次天气数据。需要注意的是，串口屏的显示需要使用串口通信协议，本示例使用的是9600波特率的串口通信。