Arduino HC-06 (подключение, управление реле)

int buff[2],i,dig,arr[2],w=1;
 
void setup(){ Serial.begin(9600);Serial.setTimeout(50);
   pinMode(9, OUTPUT); // PWM1
   pinMode(10, OUTPUT);// PWM2
   pinMode(11, OUTPUT);// P3 
   pinMode(12, OUTPUT);// P2 
   pinMode(13, OUTPUT);// P1
   pinMode(8, OUTPUT);// P4 
   pinMode(7, OUTPUT);// P5
}
 
void loop() {
 /////// ПРИЕМ ДАННЫХ С SERIAL PORT /////////////////////////
  while (Serial.available()>0){ 
   for (i=0;i<1;i++) { 
     buff[0] = Serial.parseInt(); 
     buff[1] = Serial.parseInt();}    
   Serial.println(buff[0],DEC);w=1;}

 ///////////// РАЗДЕЛЕНИЕ ЧИСЛА НА КОД КОМАНДЫ И ЗНАЧЕНИЕ /////////////////// 
 if(buff[0]>10&&w==1){ w=0;
  if(buff[0]>=10000){dig=buff[0];arr[0]=dig/1000;arr[1]=dig%1000;}
  if(buff[0]<10000&&buff[0]>=1000){dig=buff[0];arr[0]=dig/100;arr[1]=dig%100;} 
  if(buff[0]<1000){dig=buff[0];arr[0]=dig/10;arr[1]=dig%10;}   
    Serial.println(arr[0]);
    Serial.println(arr[1]);
    Serial.println(" ");
 } 
   switch(arr[0]){
     case 10: pin();break;
     case 11: analogWrite(9,arr[1]);break;
     case 12: analogWrite(10,arr[1]);break;
 }
}

void pin(){
  if(arr[1]==1){digitalWrite(13,HIGH);} 
  if(arr[1]==0){digitalWrite(13,LOW);}  
  if(arr[1]==3){digitalWrite(12,HIGH);} 
  if(arr[1]==2){digitalWrite(12,LOW);}  
  if(arr[1]==5){digitalWrite(11,HIGH);} 
  if(arr[1]==4){digitalWrite(11,LOW);}
  if(arr[1]==7){digitalWrite(8,HIGH);} 
  if(arr[1]==6){digitalWrite(8,LOW);}
  if(arr[1]==9){digitalWrite(7,HIGH);} 
  if(arr[1]==8){digitalWrite(7,LOW);}
  }