51单片机控制dht11并用lcd1602显示的代码

下面是一个基于51单片机控制DHT11并用LCD1602显示的简单代码：

#include <reg51.h>
#include <stdio.h>
#include <intrins.h>

#define DHT11_PIN P2_0  // DHT11数据线连接的单片机引脚
#define LCD_RS P0_0     // LCD1602的RS引脚
#define LCD_RW P0_1     // LCD1602的RW引脚
#define LCD_EN P0_2     // LCD1602的EN引脚
#define LCD_DAT P1      // LCD1602的数据线

unsigned char dht11_data[5];

void delay(unsigned int x) {
    unsigned int i, j;
    for (i = 0; i < x; i++) {
        for (j = 0; j < 125; j++);
    }
}

void lcd_write_cmd(unsigned char cmd) {
    LCD_RS = 0;
    LCD_RW = 0;
    LCD_EN = 0;
    LCD_DAT = cmd;
    delay(1);
    LCD_EN = 1;
    delay(1);
    LCD_EN = 0;
    delay(1);
}

void lcd_write_data(unsigned char dat) {
    LCD_RS = 1;
    LCD_RW = 0;
    LCD_EN = 0;
    LCD_DAT = dat;
    delay(1);
    LCD_EN = 1;
    delay(1);
    LCD_EN = 0;
    delay(1);
}

void lcd_init() {
    lcd_write_cmd(0x38);
    lcd_write_cmd(0x0c);
    lcd_write_cmd(0x06);
    lcd_write_cmd(0x01);
}

void lcd_display_string(unsigned char x, unsigned char y, unsigned char *p) {
    unsigned char addr;
    if (y == 0) {
        addr = 0x80 + x;
    } else {
        addr = 0xc0 + x;
    }
    lcd_write_cmd(addr);
    while (*p) {
        lcd_write_data(*p++);
    }
}

void dht11_init() {
    DHT11_PIN = 1;
    delay(500);
}

unsigned char dht11_read_byte() {
    unsigned char i, dat;
    dat = 0;
    for (i = 0; i < 8; i++) {
        while (!DHT11_PIN);
        delay(30);
        if (DHT11_PIN == 0) {
            dat <<= 1;
        } else {
            dat = (dat << 1) | 0x01;
        }
        while (DHT11_PIN);
    }
    return dat;
}

void dht11_read_data() {
    unsigned char i, checksum;
    DHT11_PIN = 0;
    delay(20);
    DHT11_PIN = 1;
    while (DHT11_PIN);
    while (!DHT11_PIN);
    while (DHT11_PIN);
    for (i = 0; i < 5; i++) {
        dht11_data[i] = dht11_read_byte();
    }
    DHT11_PIN = 1;
    checksum = dht11_data[0] + dht11_data[1] + dht11_data[2] + dht11_data[3];
    if (checksum != dht11_data[4]) {
        lcd_display_string(0, 1, "Checksum Error!");
    } else {
        lcd_display_string(0, 1, "Temp:");
        lcd_write_data(dht11_data[0] / 10 + '0');
        lcd_write_data(dht11_data[0] % 10 + '0');
        lcd_write_data('.');
        lcd_write_data(dht11_data[1] / 10 + '0');
        lcd_write_data(dht11_data[1] % 10 + '0');
        lcd_write_data('C');
        lcd_display_string(8, 1, "Hum:");
        lcd_write_data(dht11_data[2] / 10 + '0');
        lcd_write_data(dht11_data[2] % 10 + '0');
        lcd_write_data('.');
        lcd_write_data(dht11_data[3] / 10 + '0');
        lcd_write_data(dht11_data[3] % 10 + '0');
        lcd_write_data('%');
    }
}

void main() {
    lcd_init();
    lcd_display_string(0, 0, "DHT11 Temperature");
    lcd_display_string(0, 1, "and Humidity Test");
    delay(2000);
    while (1) {
        dht11_init();
        dht11_read_data();
        delay(2000);
    }
}

这个代码使用了51单片机来读取DHT11传感器的温度和湿度值，并通过LCD1602显示出来。具体实现过程中，我们需要先初始化LCD1602，然后在主函数中循环读取DHT11传感器的数据，并将温度和湿度值显示到LCD1602上。需要注意的是，DHT11传感器的数据读取过程是比较复杂的，需要按照一定的时序和协议进行操作。