STM32-ESP8266-MQTT通信

OLED用来显示调试信息

代码详情

串口格式化打印

void uart_print(UART_HandleTypeDef *huart,char* format,...) {
    char buf[128]={0};
    va_list ap;
    va_start(ap,format);
    vsprintf(buf,format,ap);
    va_end(ap);
    HAL_UART_Transmit(huart,(uint8_t*)buf,strlen(buf),HAL_MAX_DELAY);
}

中断不定长接收

// 初始化串口接收
HAL_UART_Receive_IT(&huart2,uart_buffer,1);
// 中断接收函数
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart){
    if(huart==&huart2){
        uart_time = uwTick;
        uart_index++;
        HAL_UART_Receive_IT(&huart2,(uint8_t *)&uart_buffer[uart_index],1);
    }
}

void uart_process(void){
    if(uart_index==0)return;
    if(uwTick>uart_time+100){
        memset(&uart_buffer,0,uart_index);
        uart_index=0;
        huart2.pRxBuffPtr = uart_buffer;
    }
}

MQTT消息解析

mqtt接收消息形式如下：

AT+MQTTPUB=0,"aaa","Hello from ESP8266",0,0

OK
+MQTTSUBRECV:0,"aaa",18,Hello from ESP8266

+MQTTSUBRECV:0,"aaa",18,Hello from ESP8266即为我们要解析的数据
根据该数据的特点，aaa由双引号包裹，数据长度为第2个和第3个逗号之间，数据在第3个逗号后进行针对性解析

void extract_mqtt_info(const char *str, char *info1, char *info_b) {
    const char *p1 = strchr(str, '"');  // 第一个引号
    if (!p1) return;
    const char *p2 = strchr(p1 + 1, '"'); // 第二个引号
    if (!p2) return;

    // 提取 info1
    size_t len1 = p2 - p1 - 1;
    strncpy(info1, p1 + 1, len1);
    info1[len1] = '\0';

    // 向后找逗号，找到数字部分
    const char *p_comma = strchr(p2 + 1, ',');
    if (!p_comma) return;
    int length = atoi(p_comma + 1);  // 提取长度数值

    // 再找一个逗号，找到消息体开始处
    const char *msg_start = strchr(p_comma + 1, ',');
    if (!msg_start) return;
    msg_start++;  // 跳过逗号

    // 提取信息b
    strncpy(info_b, msg_start, length);
    info_b[length] = '\0';
}

MQTT连接

uart_print(&huart2,"AT+MQTTCLEAN=0\r\n");
uart_print(&huart2,"AT+CWJAP=\"aaa\",\"aaaaaaaa\"\r\n");
uart_print(&huart2,"AT+MQTTUSERCFG=0,1,\"fs\",\"111111\",\"272935657\",0,0,\"\"\r\n");
uart_print(&huart2,"AT+MQTTCONN=0,\"47.113.191.144\",1883,1\r\n");
uart_print(&huart2,"AT+MQTTSUB=0,\"topic1\",1\r\n");

MQTT发送信息

uart_print(&huart2,"AT+MQTTPUB=0,\"topic1\",\"Ha\",0,0\r\n");

主要思路

• 先初始化，连接MQTT服务器
• 完成串口不定长接收
• 接收消息后解析并打印