#define pinBtnRed 12 

                #define pinBtnGreen 4 

                #define pinBtnBlue 3 

                #define pinBtnYellow 2
            
        

            
                #define pinU 6 

                #define pinL 9 

                #define pinD 10 

                #define pinR 11
            
        

            
                #define NUMBER_OF_CHANNELS 4 

                int Btns[NUMBER_OF_CHANNELS]={pinBtnRed,pinBtnGreen,pinBtnBlue,pinBtnYellow}; 

                int Leds[NUMBER_OF_CHANNELS]={pinR,pinL,pinU,pinD};
            
        

            
                bool LedIsOn[NUMBER_OF_CHANNELS]={false,false,false,false}; 

                bool BtnIsPressed[NUMBER_OF_CHANNELS]={false,false,false,false};
            
        

            
                void setup() { 

                   for(byte k=0;k<NUMBER_OF_CHANNELS;k++){ 

                     pinMode(Btns[k],INPUT_PULLUP); 

                     pinMode(Leds[k],OUTPUT); 

                   } 

                }
            
        

            
                void LedOn(byte channel){ 

                  digitalWrite(Leds[channel],HIGH); 

                  LedIsOn[channel]=true; 

                }
            
        

            
                void LedOff(byte channel){ 

                  digitalWrite(Leds[channel],LOW); 

                  LedIsOn[channel]=false; 

                }
            
        

            
                void toggleLed(byte channel){ 

                  if(LedIsOn[channel]){ 

                    LedOff(channel); 

                  } else { 

                    LedOn(channel); 

                  } 

                }
            
        

            
            	if(digitalRead(Btns[channel])==LOW){
            
        

                
                    else { 

                       BtnIsPressed[channel]=false; 

                    }
                
            

            
                if(digitalRead(Btns[channel])==LOW){ 

                   if(! BtnIsPressed[channel]){ 

                     BtnIsPressed[channel]=true; 

                     toggleLed(channel); 

                   } 

                }
            
        

            
              delay(20);
            
        

            
                void loop() { 

                  for(byte channel=0;channel<NUMBER_OF_CHANNELS;channel++){ 

                    if(digitalRead(Btns[channel])==LOW){ 

                      if(! BtnIsPressed[channel]){ 

                        BtnIsPressed[channel]=true; 

                        toggleLed(channel); 

                      } 

                    } else { 

                      BtnIsPressed[channel]=false; 

                    } 

                  } 

                  delay(20); 

                }