Comparing the current output with the last one

[hatam_mn]

hello every one
i want to compare two outputs from interrupt but when i save the last one in a parameter " f " the current one "Tx " stop changing and "m" won't increase.

#include "tc_lib.h"

using namespace arduino_due;

#define CAPTURE_TIME_WINDOW 2500000 // usecs
#define ANALOG_PIN 7
#define ANALOG_VALUE 127 // values in the interval [0,255] 


capture_tc0_declaration();
auto& capture_pin2=capture_tc0;
volatile float Tx = 0 ;

volatile float f = 0 ;

volatile float t = 0 ;
 
volatile int m = 0 ;

void setup() {
 
  Serial.begin(19200);
   Serial3.begin(38400);

  capture_pin2.config(CAPTURE_TIME_WINDOW);
attachInterrupt(digitalPinToInterrupt(2), measure , LOW );

}

 void measure (){
  uint32_t status,duty,period;
  status=capture_pin2.get_duty_and_period(duty,period);

 t = (static_cast<double>(duty)/static_cast<double>(capture_pin2.ticks_per_usec()) );
  if ( (t > 1400) && (t < 1600))
{  Tx = t ;}

 }
void loop() {

if (Tx - f > 1)
{
  
 f = Tx;
 
  m++;

}
  delay(20);
  
Serial3.println(m);
}

this is the interrupt output and i want to count the number of spikes

any little help would be greatly appreciated in advance.

[UKHeliBob]

What happens if you declare duty and period as static global variables instead of declaring them within the ISR ?

[hatam_mn]

this error is shown while i wanted to compile :

exit status 1
no matching function for call to 'arduino_due::tc_lib::capture<(arduino_due::tc_lib::timer_ids)0u>::get_duty_and_period(volatile uint32_t&, volatile uint32_t&)'

[ruilviana]

Hi @hatam_mn

@hatam_mn

volatile float Tx = 0 ;

volatile float f = 0 ;

volatile float t = 0 ;

Why are Tx, f and t defined as a float?
What happens if I use long?

RV mineirin

[hatam_mn]

Arduino Reference - Arduino Reference

Look at this link the part of " variables "
They are defined perfectly

[UKHeliBob]

@hatam_mn

They are defined perfectly

The question is why are they floats ?

[hatam_mn]

Because i want to capture the time of event that they have some digit after point like 1508.437 . i'm in favor of increasing the precision of measuring so i need to define them in to a float variables.
By the way i have found the solution and it was so easy and infront of my eyes and it was the line i defined the "f = Tx".
It must be out of brackets of if .