51单片机使用MQ-2实时检测烟雾浓度，根据烟雾浓度调节PWM风扇转速并且使用LCD1602显示当前转速和当前烟雾浓度的C语言代码

以下是基于51单片机的使用MQ-2实时检测烟雾浓度，根据烟雾浓度调节PWM风扇转速并且使用LCD1602显示当前转速和当前烟雾浓度的C语言代码： ```c #include <reg52.h> #include <intrins.h> #define uchar unsigned char #define uint unsigned int #define LCD_Data_Port P0 sbit LCD_RS = P2^6; sbit LCD_RW = P2^5; sbit LCD_EN = P2^7; sbit MQ2 = P3^2; sbit FAN = P1^4; uchar code table[]=" fan speed:";//lcd显示 uchar PWM_val; //PWM占空比 uint smoke_val; //烟雾浓度 void delay(uint xms) //延时函数 { uint i, j; for(i = xms; i > 0; i--) for(j = 110; j > 0; j--); } void LCD_Write_Cmd(uchar cmd) //写入命令函数 { LCD_RS = 0; LCD_RW = 0; LCD_Data_Port = cmd; LCD_EN = 1; _nop_(); _nop_(); _nop_(); _nop_(); LCD_EN = 0; delay(5); } void LCD_Write_Data(uchar dat) //写入数据函数 { LCD_RS = 1; LCD_RW = 0; LCD_Data_Port = dat; LCD_EN = 1; _nop_(); _nop_(); _nop_(); _nop_(); LCD_EN = 0; delay(5); } void LCD_Init() //LCD初始化函数 { LCD_Write_Cmd(0x38); //开显示，16x2，5x7点阵 LCD_Write_Cmd(0x0c); //开显示不显示光标 LCD_Write_Cmd(0x06); //文字不动，地址加1 LCD_Write_Cmd(0x01); //清屏命令 } void init_Timer0() //定时器0初始化函数 { TMOD|=0x01; TH0=0; TL0=0; ET0=1; TR0=1; EA=1; } void Timer0_ISR() interrupt 1 //定时器0中断服务程序 { static uint cnt; if(cnt == 100) //每隔100ms读取一次烟雾浓度 { cnt = 0; smoke_val = (ADC_Read(0)>>2); //读取烟雾浓度 } cnt++; if(smoke_val > 200) //根据烟雾浓度调节PWM占空比 PWM_val = 255; else if(smoke_val > 100) PWM_val = 200; else if(smoke_val > 50) PWM_val = 150; else if(smoke_val > 20) PWM_val = 100; else PWM_val = 0; FAN = (PWM_val > TH0); //根据PWM占空比调节风扇转速 } uchar ADC_Read(uchar ch) //ADC读取函数 { ADC_CONTR = ADC_POWER | ADC_SPEEDLL | ch; delay(1); ADC_CONTR |= ADC_START; while(!(ADC_CONTR & ADC_FLAG)); ADC_CONTR &= ~ADC_FLAG; return ADC_RES; } void main() { LCD_Init(); //初始化LCD init_Timer0(); //初始化定时器0 while(1) { LCD_Write_Cmd(0x80); //第一行 for(uchar i=0; i<13; i++) LCD_Write_Data(table[i]); LCD_Write_Data((uchar)(PWM_val/10)+'0'); //显示风扇转速 LCD_Write_Data((uchar)(PWM_val%10)+'0'); LCD_Write_Data(' '); LCD_Write_Data(' '); LCD_Write_Cmd(0xc0); //第二行 LCD_Write_Data('s'); LCD_Write_Data('m'); LCD_Write_Data('o'); LCD_Write_Data('k'); LCD_Write_Data('e'); LCD_Write_Data(':'); LCD_Write_Data(' '); LCD_Write_Data((uchar)(smoke_val/100)+'0'); //显示烟雾浓度 LCD_Write_Data((uchar)(smoke_val/10%10)+'0'); LCD_Write_Data((uchar)(smoke_val%10)+'0'); delay(100); } } ``` 注：本代码仅供参考，具体实现可能因硬件环境等因素而有所不同，使用时请结合实际情况进行修改。