51单片机如何连接MQ-2烟雾传感器

#include "reg51.h"
#include "intrins.h"

#define UPID 0X6F
#define MYID 0x08

sfr AUXR=0x8e;//STC应用该辅助寄存器

/*Declare SFR associated with the ADC*/
sfr ADC_CONTR = 0xBC; //ADC control register
sfr ADC_RES = 0xBD; //ADC high 8-bit result register
sfr ADC_LOW2 = 0xBE; //ADC low 2-bit result register
sfr P1ASF = 0x9D; //P1 secondary function control register

/*Define ADC operation const for ADC_CONTR*/
#define ADC_POWER 0x80 //ADC power control bit
#define ADC_FLAG 0x10 //ADC complete flag
#define ADC_START 0x08 //ADC start control bit
#define ADC_SPEEDLL 0x00 //420 clocks
#define ADC_SPEEDL 0x20 //280 clocks
#define ADC_SPEEDH 0x40 //140 clocks
#define ADC_SPEEDHH 0x60 //70 clocks

unsigned char bufsend[10];

void Delay1ms(unsigned int x) //@11.0592MHz
{
unsigned char i,j;
   while(x–)
{
_nop_();
       i= 11;
       j= 190;
       do
           {
while(–j);
           }
           while(–i);
}
}

void UartInit(void)       //9600bps@11.0592MHz
{
   PCON &= 0x7F;       //波特率不倍速
   SCON = 0x50;       //8位数据,可变波特率
   AUXR &= 0xBF;       //定时器时钟12T模式
   AUXR &= 0xFE;       //串口1选择定时器1为波特率发生器
   TMOD &= 0x0F;       //设置定时器模式
   TMOD |= 0x20;       //设置定时器模式
   TL1 = 0xFD;       //设置定时初始值
   TH1 = 0xFD;       //设置定时重载值
   ET1 = 0;       //禁止定时器%d中断
   TR1 = 1;       //定时器1开始计时
}

void InitADC()
{
P1ASF = 0x01; //Open 8 channels ADC function
ADC_RES =0; //Clear previous result
ADC_CONTR=ADC_POWER | ADC_SPEEDLL;
Delay1ms(2); //ADC power-on and delay
}

unsigned char GetADCResult(unsigned char ch)
   {
ADC_CONTR=ADC_POWER | ADC_SPEEDLL| ch | ADC_START;
       _nop_(); //Must wait before inquiry
_nop_();
_nop_();
       _nop_();
while(!(ADC_CONTR & ADC_FLAG)); //Wait complete flag
       ADC_CONTR &=~ADC_FLAG; //Close ADC
return ADC_RES; //Return ADC result
}

unsigned char DataSendPreprocess()
{
unsigned char i,t=0;
bufsend[0]=0x7f; //起始字节
bufsend[1]=0x5f; //接受者地址
bufsend[2]=0x08; //发送者地址
bufsend[3]=3; //数据长度
bufsend[4]=0x84; //传感器类型0x13—>可燃气体传感器MQ-2
bufsend[5]=0; //AD通道号P1.0<——>可燃气体传感器MQ-2的AO
bufsend[6]=GetADCResult(0);//AD通道号0转换后数据
for(i=1;i<=6;i++) //异或校验码生成
t^=bufsend[i];
bufsend[7]=t; //校验字节
bufsend[8]=0xff; //结束字节
return 9;
}

void DataSend(unsigned char ss[],unsigned char len)
   {
unsigned char i;
       for(i=0;i<len;i++)
       {
SBUF=ss[i];
       while(TI==0);
TI=0;
}
}
void main()
   {
unsigned char len;
       InitADC();
UartInit();
while(1)
           {
len=DataSendPreprocess();
               DataSend(bufsend,len);
               Delay1ms(1000);
}
}