LED 번갈아 페이딩

#include <iostream>
 #include <wiringPi.h>
 #include <unistd.h>
 using namespace std;

 #define PWM_LED_G       13      // this is PWM0, pin 12
 #define PWM_LED_R     18

  #define BUTTON_GPIO   27      // this is GPIO27, pin 13
 bool running = true;          // fade in/out until button pressed


 int main() {                             // must be run as root
    wiringPiSetupGpio();                  // use the GPIO numbering
    pinMode(PWM_LED_R, PWM_OUTPUT);         // the PWM LED - PWM0
    pinMode(PWM_LED_G, PWM_OUTPUT);
   pinMode(BUTTON_GPIO, INPUT);          // the button input
 
    pwmSetRange(1000);

   
    while(1) {
       for(int i=1; i<1000; i++) {       // Fade fully on
          pwmWrite(PWM_LED_R, i);
         usleep(1000);
       }
       for(int i=999; i>=0; i--) {       // Fade fully off
          pwmWrite(PWM_LED_R, i);
          usleep(1000);
       }

     for(int j=1;j<1000;j++){
         pwmWrite(PWM_LED_G, j);
         usleep(1000);
      }
     for(int j=999;j>=0;j--){
         pwmWrite(PWM_LED_G, j);
         usleep(1000);
    }
 }
  
 }