return(result>>1)

[wiliam]

Hi guys, i have a big dubt, i have been doing project for one of my subjects on university and i cant understand why i have to have this return, return(result>>1) for it to get the return rigth

this is the function where i use it:

uint16_t getPulseWidth1()
{


    uint16_t i,resultado1;


    for(i=0;i<60000;i++)
    {
        if(!(PIN_sd & (1<<ECHO1)))
        continue;
        else
        break;
    }


    if(i==60000)
    return Time_out_sd1;




    TCCR1A=0x00;
    TCCR1B=(1<<CS10);
    TCNT1=0x00;
    
    
    for(i=0;i<60000;i++)
    {
        if(PIN_sd & (1<<ECHO1))
        {
            if(TCNT1>60000) break; else continue;
        }
        else
        break;
    }


    if(i==1900)
    return sem_obst_sd1;


    resultado1=TCNT1;


    TCCR1B=0x00;


    if(resultado1>1900)
    return sem_obst_sd1;
    else
    return (resultado1>>1);
}

if any one could explain it to me, thaks a lot, sry for the bad ing :/

[laserlight]

I have no idea what this is function is for in the first place, but I can tell you that a right shift by 1 is equivalent to division by 2, so obviously without that you have a bug that requires you to divide by 2 to fix it.

[wiliam]

this code is for the HC-SR004 ultrasond sensor, this function returns a number
then
(number*2)/58 to get the distence in cm but the original formula is number/58, so thats why i must multiply for 2 thaks a lot!
now i wil try to fix the bug!