How to measure frequency in arduino using pulseIn() function?

Question

i am newbie in arduino and i have small project i read that pulseIn function return length of the pulse in microseconds and

frequency(HZ)=1/time(second)

so i hope below code to measure frequency value is correct otherwise please notify me

int senserpin=8;
int sensordelay=1000; 
float duration;
float freq;

void setup{
pinMode(senserpin,INPUT);
serial.begin(9600);
}

void loop()
{
duration=pulsein(senserpin,high)
freq=1/(duration*1000000)// multiply duration *1000000 to convert from microseconds to seconds 
serail.print("frequency");
serail.print(freq);

delay(sensordelay)
}

Answer 1

You measured only high time. You need to measure both for calculating frequency and period. I hope this will work for you.

int highTime;    //integer for storing high time
int lowTime;     //integer for storing low time
float period;    // integer for storing period
float freq;      //storing frequency

void setup()
{
    pinMode(8,INPUT);  //Setting pin as input
}

void loop()
{
    highTime=pulseIn(8,HIGH);  //read high time
    lowTime=pulseIn(8,LOW);    //read low time
    period = highTime+lowTime; // Period = Ton + Toff
    freq=1000000/period;       //getting frequency with totalTime is in Micro seconds
    delay(1000);
}