title: Arduino problems:" 'i' was not declared in this scope"
body: <p>Having alot of problems with this code that is made for an arduino reaction game. I am not sure if I maybe have declared i twice or something. Arduino tells me that the problem is here: "if ( i == success_led )". </p>
  
  <pre><code>// Public Domain 2012 by A.Coster
  
  // some constants for readability, using booleans to save memory
  boolean ON  = 1 ;
  boolean OFF = 0 ;
  
  // Arduino pin setup - there are 3 pins used for LEDs,
  // 1 for push-button. The pin at index success_led is
  // the one the user should try to hit.
  byte led_pins[3]       = {8,9,10} ;
  byte button_pin        =    2 ;
  byte success_led       =    1 ;  // refers to pin 9
  
  // time_change is the number of milliseconds to add upon
  // failure or subtract upon success.
  // colorswitch_delay is the amount of time that the LED stays
  // on. This value has time_change added to/subtracted from it.
  // So that the user knows which LED was lit up when they hit
  // the button, push_pause defines the number of milliseconds
  // that the LED will stay on after the button is pressed.
  unsigned int time_change       =   50 ;
  unsigned int colorswitch_delay =  500 ;
  unsigned int push_pause        = 2000 ;
  
  void setup(){
  
      for (int i=0 ; i ;) ;      
      pinMode( led_pins[i], OUTPUT ) ;
  
      pinMode( button_pin, INPUT ) ;
  }
  
  void loop(){
      // need to keep track of button presses
      // so set the button state to 0 and overwrite
      // later upon button press
      boolean button_state = OFF ;
  
      // sequentially turn on each LED
      for ( int i=0 ; i        digitalWrite( led_pins[i], HIGH ) ;
  
          // Check for a button press every 5 milliseconds
          for ( int t=0 ; t            button_state = digitalRead( button_pin ) ;
  
              // if the button has been pressed, stop
              // switching LEDs so the user knows, and
              // then check if it was the success_led
              if ( button_state == ON ){
                  delay( push_pause ) ;
  
                  // set the button state back to off
                  button_state = OFF ;
                  if ( i == success_led )
                      // if the user hit the right LED,
                      // make it more challenging by
                      // reducing the delay between LED
                      // switches.
                      colorswitch_delay -= time_change ;
                  else
                      // if the user was wrong, make it
                      // easier by increasing the delay.
                      colorswitch_delay += time_change ;
                      break ;
                  }
              delay( 5 ) ;
          }
          // and turn it off before looping through
          // to turn the next LED on.
          digitalWrite( led_pins[i], LOW ) ;
      }
  }
  </code></pre>