plis help ,I'm trying to make a pulse counter

Other Hardware Sensors
1

I'm trying to make a pulse counter and I found several sketches, but I think they need some changes in order to function, I'm trying to read is a pulse of 5 V, and its duration counting 5 pulses turn on an LED, and I have a question, 1/2 can count pulse,

please and thank you

#define MainPeriod 100 // measurement frame, milliseconds
#define f_input_pin 2 // input pin for pulseIn

long previousMillis = 0;
unsigned long duration=0; // receive pulse width
long pulsecount=0;

void setup()
{
pinMode(f_input_pin, INPUT);
Serial.begin(19200);
}

void loop()
{
unsigned long currentMillis = millis();
if (currentMillis - previousMillis >= MainPeriod)
{
previousMillis = currentMillis;
// write current time and F values to the serial port
Serial.print(currentMillis);
Serial.print(" "); // separator!
float Freq=0.5e6/float(duration); // assume pulse duty cycle 0.5
Freq*=pulsecount;
Serial.print(Freq);
Serial.print(" ");
Serial.print(pulsecount);
Serial.print(" ");
Serial.println(duration);
duration=0;
pulsecount=0;
}
// instead of single measurement per cycle - accumulate and average
duration += pulseIn(f_input_pin, HIGH, MainPeriod*900);
pulsecount++;
}

2

peter_29:
I think they need some changes in order to function

Well it either functions or not. If it doesn't function as you would like, you'll need to describe what is and isn't happening.

3

You were doing so well until you threw this spanner in the works

  duration += pulseIn(f_input_pin, HIGH, MainPeriod*900);

You are now totally disrupting the flow of the loop and rendering your subtractive millis technique, useless.