51单片机mq7传感器在1602显示浓度代码

以下是基于51单片机和1602液晶屏幕的MQ7传感器浓度显示代码：

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

#define LCD1602_DB P0
sbit LCD1602_RS = P2^0;
sbit LCD1602_RW = P2^1;
sbit LCD1602_EN = P2^2;

sbit MQ7_DO = P3^5;

unsigned int ADC_Value;

void delay_ms(unsigned int ms)
{
    unsigned int i, j;
    for(i=0; i<ms; i++)
        for(j=0; j<114; j++);
}

void LCD1602_WriteCommand(unsigned char Command)
{
    LCD1602_RS = 0;
    LCD1602_RW = 0;
    LCD1602_EN = 1;
    _nop_();
    LCD1602_DB = Command;
    _nop_();
    LCD1602_EN = 0;
    delay_ms(2);
}

void LCD1602_WriteData(unsigned char Data)
{
    LCD1602_RS = 1;
    LCD1602_RW = 0;
    LCD1602_EN = 1;
    _nop_();
    LCD1602_DB = Data;
    _nop_();
    LCD1602_EN = 0;
    delay_ms(2);
}

void LCD1602_Init()
{
    LCD1602_WriteCommand(0x38);
    LCD1602_WriteCommand(0x0c);
    LCD1602_WriteCommand(0x06);
    LCD1602_WriteCommand(0x01);
}

void ADC_Init()
{
    AUXR |= 0x10;
    ADC_CONTR = 0x81;
}

unsigned int ADC_Read(unsigned char Channel)
{
    ADC_CONTR = 0x81 | (Channel << 3);
    delay_ms(2);
    ADC_CONTR |= 0x10;
    while(!(ADC_CONTR & 0x20));
    ADC_CONTR &= ~0x20;
    return ADC_RES;
}

void main()
{
    unsigned char High, Low;
    float value;
    ADC_Init();
    LCD1602_Init();
    LCD1602_WriteCommand(0x80);
    LCD1602_WriteData('M');
    LCD1602_WriteData('Q');
    LCD1602_WriteData('7');
    LCD1602_WriteCommand(0xc0);
    LCD1602_WriteData('C');
    LCD1602_WriteData('o');
    LCD1602_WriteData('n');
    LCD1602_WriteData('c');
    LCD1602_WriteData('e');
    LCD1602_WriteData('n');
    LCD1602_WriteData('t');
    delay_ms(2000);
    while(1)
    {
        High = ADC_Read(0);
        Low = ADC_Read(1);
        ADC_Value = (High << 8) | Low;
        value = ADC_Value * 5.0 / 1023;
        LCD1602_WriteCommand(0x80);
        LCD1602_WriteData('C');
        LCD1602_WriteData('o');
        LCD1602_WriteData('n');
        LCD1602_WriteData('c');
        LCD1602_WriteData(':');
        LCD1602_WriteData(' ');
        LCD1602_WriteData((int)value/10 + '0');
        LCD1602_WriteData((int)value%10 + '0');
        LCD1602_WriteData('p');
        LCD1602_WriteData('p');
        LCD1602_WriteData('m');
        delay_ms(1000);
    }
}

上述代码中，我们使用了51单片机的ADC模块读取了MQ7传感器的模拟信号，并将其转化为数字信号进行处理。同时，我们通过1602液晶屏幕实时显示MQ7传感器检测到的浓度值。需要注意的是，由于MQ7传感器输出的是模拟信号，因此需要通过ADC模块进行转化，才能得到准确的浓度值。