stm32通过esp8266接收onenet数据库函数

要使用STM32通过ESP8266接收OneNet数据库中的数据，你需要实现以下几个步骤：

1. 配置ESP8266模块，使其能够连接到WiFi网络并访问OneNet平台。

2. 通过STM32与ESP8266建立UART串口通信，以便STM32能够向ESP8266发送AT指令。

3. 使用ESP8266模块向OneNet平台发送HTTP请求，并接收OneNet平台返回的数据。

4. 在STM32中解析接收到的数据，并进行相应的处理。

下面是一个简单的示例代码，可以帮助你了解如何在STM32中实现这个功能：

#include "stm32f10x.h"
#include <stdio.h>
#include <string.h>

#define ESP8266_BAUDRATE 115200
#define ONE_NET_URL "http://api.heclouds.com/devices/{device_id}/datapoints?datastream_id={datastream_id}&limit=1"
#define ONE_NET_DEVICE_ID "{your_device_id}"
#define ONE_NET_DATASTREAM_ID "{your_datastream_id}"

char esp_rx_buf[256];

void USART1_IRQHandler(void)
{
    if (USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
    {
        static uint8_t rx_pos = 0;
        esp_rx_buf[rx_pos++] = USART_ReceiveData(USART1);
        if (esp_rx_buf[rx_pos - 1] == '\n')
        {
            esp_rx_buf[rx_pos] = '\0';
            rx_pos = 0;
            printf("Received from ESP8266: %s", esp_rx_buf);
        }
    }
}

void esp8266_send_at_cmd(char *cmd, char *resp, uint16_t timeout)
{
    char rx_buf[256];
    uint16_t rx_pos = 0;
    uint32_t start_time = HAL_GetTick();
    uint32_t elapsed_time;
    memset(rx_buf, 0, sizeof(rx_buf));
    USART_SendString(USART1, cmd);
    while (1)
    {
        if (HAL_GetTick() - start_time > timeout)
        {
            printf("Error: Timeout\r\n");
            return;
        }
        if (USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
        {
            rx_buf[rx_pos++] = USART_ReceiveData(USART1);
            if (rx_buf[rx_pos - 1] == '\n')
            {
                rx_buf[rx_pos] = '\0';
                rx_pos = 0;
                printf("%s", rx_buf);
                if (strstr(rx_buf, resp) != NULL)
                {
                    return;
                }
                memset(rx_buf, 0, sizeof(rx_buf));
            }
        }
    }
}

void esp8266_init(void)
{
    esp8266_send_at_cmd("AT\r\n", "OK", 2000);
    esp8266_send_at_cmd("AT+CWMODE=1\r\n", "OK", 2000);
    esp8266_send_at_cmd("AT+CWJAP=\"your_SSID\",\"your_password\"\r\n", "OK", 10000);
}

void esp8266_send_http_request(void)
{
    char http_req[256];
    sprintf(http_req, "AT+HTTPGET=\"%s\"\r\n", ONE_NET_URL);
    esp8266_send_at_cmd(http_req, "+HTTPACTION: 0,200,", 10000);
}

void parse_one_net_data(char *data)
{
    char *p = strtok(data, ",");
    while (p != NULL)
    {
        if (strstr(p, "value") != NULL)
        {
            printf("Received value: %s\r\n", p + strlen("value\":"));
            break;
        }
        p = strtok(NULL, ",");
    }
}

int main()
{
    USART_InitTypeDef USART_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;
    GPIO_InitTypeDef GPIO_InitStructure;
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
    USART_InitStructure.USART_BaudRate = ESP8266_BAUDRATE;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
    USART_Init(USART1, &USART_InitStructure);
    USART_Cmd(USART1, ENABLE);
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
    esp8266_init();
    while (1)
    {
        esp8266_send_http_request();
        HAL_Delay(1000);
        parse_one_net_data(esp_rx_buf);
        HAL_Delay(5000);
    }
}

这段代码实现了通过STM32与ESP8266建立UART串口通信，并使用ESP8266模块向OneNet平台发送HTTP请求，接收OneNet平台返回的数据，并在STM32中解析接收到的数据。

请注意，这只是一个简单的示例代码，可能需要根据你的具体需求进行修改。