Arduino interrupt realizes rising edge detection and executes other functions

One 、 Corresponding procedure

int ledPin    = 13;  // LED  Connected to digital pin  13
int PPS       = 2;   // GNSS From the receiver PPS Pulse signal   Access port 

int PWM_20HZ  = 3;   // 20hz Pulse port of frequency   -  Trigger the camera  
int PWM_200HZ = 11;   // 200hz Pulse port of frequency  -  to IMU Trigger 

void setup() 
{
  pinMode(ledPin, OUTPUT);
  pinMode(PWM_20HZ, OUTPUT);
  pinMode(PWM_200HZ, OUTPUT);
  pinMode(PPS,INPUT_PULLUP);                //  Set the key to input mode , Pull up inside 
  attachInterrupt(0, PWMProgram, RISING);   //  The rising edge triggers the interrupt  0, call  testProgram  function 
}

void PWMProgram()
{
  TCCR2A = _BV(COM2A1) | _BV(COM2B1) | _BV(WGM20);  
  TCCR2B = _BV(CS22);  
  OCR2A  = 180;  
  OCR2B  = 50;
}


void loop()
{
}

shortcoming ： The frequency cannot be adjusted arbitrarily