#include "dht11.h" #include "protocol.h" #include "lcd.h" #include "string.h" #include <stdio.h> #include "gpio.h" #include "usart.h" #define DHT11_DATA_LOW_TIMEOUT 80 #define DHT11_DATA_HIGH_TIMEOUT 90 #define DHT11_RESPONSE_TIMEOUT 40 #define DHT11_BIT_TIMEOUT 60 DHT11_StatusTypeDef DHT11_ReadData(DHT11_Data_TypeDef* data) { uint8_t buffer[5] = {0}; uint8_t i, j; uint32_t count; // 发送开始信号 HAL_GPIO_WritePin(GPIOB, GPIO_PIN_8, GPIO_PIN_SET); HAL_Delay(18); HAL_GPIO_WritePin(GPIOB, GPIO_PIN_8, GPIO_PIN_RESET); // 等待DHT11响应 count = 0; while (HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_8) == GPIO_PIN_RESET) { count++; if (count > DHT11_RESPONSE_TIMEOUT) { return DHT11_ERROR; } HAL_Delay(1); } count = 0; while (HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_8) == GPIO_PIN_SET) { count++; if (count > DHT11_RESPONSE_TIMEOUT) { return DHT11_ERROR; } HAL_Delay(1); } // 读取40位数据 for (i = 0; i < 40; i++) { count = 0; while (HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_8) == GPIO_PIN_RESET) { count++; if (count > DHT11_DATA_LOW_TIMEOUT) { return DHT11_ERROR; } } count = 0; while (HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_8) == GPIO_PIN_SET) { count++; if (count > DHT11_DATA_HIGH_TIMEOUT) { return DHT11_ERROR; } } buffer[i / 8] <<= 1; if (count > DHT11_BIT_TIMEOUT) { buffer[i / 8] |= 0x01; } } // 验证数据是否正确 if (buffer[4] != (buffer[0] + buffer[1] + buffer[2] + buffer[3])) { return DHT11_ERROR; } // 解析数据 data->humidity = buffer[0]; data->temp_int = buffer[2]; data->temp_dec = buffer[3]; return DHT11_OK; } void text_func_1() { DHT11_Data_TypeDef data; DHT11_ReadData(&data); printf("-->"); printf("%d.%c %d%%",data.temp_int, data.temp_dec, data.humidity); HAL_Delay(1000); if (DHT11_ReadData(&data) == DHT11_OK){ char str[16]; sprintf(str, "T:%d.%dC H:%d%%", data.temp_int, data.temp_dec, data.humidity); HAL_UART_Transmit(&huart1, (uint8_t*)str, strlen(str), HAL_MAX_DELAY); HAL_Delay(1000); } }改错

代码中需要修改的地方：

1. 在 `DHT11_ReadData` 函数中，`buffer[i / 8]` 需要先清零再左移，否则可能导致结果错误。

修改前：`buffer[i / 8] <<= 1;`

修改后：`buffer[i / 8] = 0; buffer[i / 8] |= 0x01 << (7 - (i % 8));`

2. 在 `text_func_1` 函数中，需要判断 `DHT11_ReadData` 函数返回值是否为 `DHT11_OK`，如果不是，则不执行后面的代码。

修改前：

DHT11_ReadData(&data); 
printf("-->"); 
printf("%d.%c %d%%",data.temp_int, data.temp_dec, data.humidity); 
HAL_Delay(1000); 
if (DHT11_ReadData(&data) == DHT11_OK){ 
    char str[16];     
    sprintf(str, "T:%d.%dC H:%d%%", data.temp_int, data.temp_dec, data.humidity);         
    HAL_UART_Transmit(&huart1, (uint8_t*)str, strlen(str), HAL_MAX_DELAY);     
    HAL_Delay(1000); 
}

修改后：

if (DHT11_ReadData(&data) == DHT11_OK){ 
    printf("-->"); 
    printf("%d.%c %d%%",data.temp_int, data.temp_dec, data.humidity); 
    HAL_Delay(1000); 
    char str[16];     
    sprintf(str, "T:%d.%dC H:%d%%", data.temp_int, data.temp_dec, data.humidity);         
    HAL_UART_Transmit(&huart1, (uint8_t*)str, strlen(str), HAL_MAX_DELAY);     
    HAL_Delay(1000); 
}