[51] Interfacing HC-SR04 ultrasonic distance sensor with at89c2051

[Sidaray]

Hi sir,
I am using keil, In program for trigger pin i am giving 10us of pulse as data sheet of ultrasonic sensor but it is not responding through echo pin, P1.7=trigger and P1.6 echo pin.
Here i am not getting the problem whether it is in circuit connection or in code, But the same connection which i am using for led blink and sending data serially its working fine, Problem is in ultrasonic.

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Code C - [expand]
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sbit trig=P1^7;
sbit echo=P1^6; 
sbit led=P1^5;
 
unsigned int y,z,x,m;
unsigned char c,d=0,e;
 
void serial_init()
{
//  delay(50);
    TMOD = 0x21;
    TH1 = 0xFD; //set baud rate to 9600
    SCON = 0x50; //mode 1 and recieve enable
    TR1 = 1;    //Turn ON Timer
}
 
void delay(unsigned int n)  
{
    unsigned int i,j;
    for(i=0;i<n;i++)
    {
        for(j=1275;j>0;j--);
    }
}
 
void pulse()
{
//  TMOD=0x01;
 
    //trig=1;
    TH0=0xff;
    TL0=0xf7;
    trig=1;
    TR0=1;
    while(TF0==0);
    TR0=0;
    TF0=0;
    trig=0; 
 
}
 
 void conversion(ch1)
{
 // unsigned char a,b,c,d,e;
    unsigned char a,b;
    a=ch1;      //FOR CONVERSION TO ACTUAL ROOM TEMPERATURE
    b=a/10;
    c=a%10;
    d=b/10;
    e=b%10;
 
    d=d+0x30;
    e=e+0x30;
    c=c+0x30;
 
    
    delay(1);
    delay(1);
    delay(1);
    delay(1);
}
 
void main()
{
    trig=0;
    echo=1;
    led=0;
    TMOD=0X01;
    echo=0;
    trig=0;
 
 
 
    while(1)
    {
    //  TMOD=0X01;
        pulse();
        TH0=TL0=0x00;
        while(!echo);
        TR0=1;
        while(echo);
            TR0=0;
 
        x=TH0;
        m=TL0;
        y=(x*256)+m;
 
        d=(y*1.085)/58;   
        if(d==10)
        {
        led=1;  
        }
        conversion(d);
 
                     serial_init();
                     SBUF='R';
                     while(!TI);
                     TI=0;
                     SBUF=d;
                     while(!TI);
                     TI=0;
                     SBUF=e;
                     while(!TI);
                     TI=0;
                     SBUF=c;
                     while(!TI);
                     TI=0;
                     SBUF=0x0D;
                     while(!TI);
                     TI=0;
                     delay(50);
        
    }
}

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[udayan92]

What microcontroller are you using..?
Also it looks to me,reading from your program,that you are building a temperature sensing system for your home.Am I right..?
If not,then explain what are you trying to do through the program.