hoe zorg ik voor dit loopje?

#include <SoftwareSerial.h>
SoftwareSerial BT(10, 11); 
// creates a "virtual" serial port/UART
// connect BT module TX to D10
// connect BT module RX to D11
// connect BT Vcc to 5V, GND to GND
void setup()  
{
  // set digital pin to control as an output
  pinMode(12, OUTPUT);
  // set the data rate for the SoftwareSerial port
  BT.begin(9600);
  // Send test message to other device
  BT.println("Hello from Arduino");
}
char a; // stores incoming character from other device
void loop() 
{
  if (BT.available())
  // if text arrived in from BT serial...
  {
    a=(BT.read());
    if (a=='h')
    {
      digitalWrite(12, HIGH);
      BT.println("LED on");
    }
    if (a=='l')
    {
      digitalWrite(12, LOW);
      BT.println("LED off");
    }
    if (a=='b')
    {
  digitalWrite(12, HIGH);  // Zet de LED aan door het voltage hoog te maken
  delay(1000);
  
  digitalWrite(12, LOW);   // Zet de LED uit door het voltage laag te maken
  delay(1000); 
    }
    if (a=='?')
    {
      BT.println("Send 'h' to turn LED on");
      BT.println("Send 'l' to turn LED off");
    }   
   
    // you can add more "if" statements with other characters to add more commands
  
 

  
    }
 }

#include <SoftwareSerial.h>
SoftwareSerial BT(10, 11); 
// creates a "virtual" serial port/UART
// connect BT module TX to D10
// connect BT module RX to D11
// connect BT Vcc to 5V, GND to GND
boolean loopje =true;
void setup()  
{
  // set digital pin to control as an output
  pinMode(12, OUTPUT);
  // set the data rate for the SoftwareSerial port
  BT.begin(9600);
  // Send test message to other device
  BT.println("Hello from Arduino");
}
char a; // stores incoming character from other device
void loop() 
{
  if (BT.available())
  // if text arrived in from BT serial...
  {
    a=(BT.read());
    if (a=='h')
    {
      digitalWrite(12, HIGH);
      BT.println("LED on");
    }
    if (a=='l')
    {
      digitalWrite(12, LOW);
      BT.println("LED off");
    }
    if (a=='b')
    {
      loopje =true;
      while(loopje){
         
   digitalWrite(12, HIGH);  // Zet de LED aan door het voltage hoog te maken
  delay(1000);
   digitalWrite(12, LOW);   // Zet de LED uit door het voltage laag te maken
  delay(1000); 
  BT.println("LED ON OFF");
  if (BT.available())
  {
    a=(BT.read());
    if(a=='l')
    {
      loopje = false;
      digitalWrite(12,LOW);
      BT.println("LED OFF");
        }
   return;
     }
     }
  }
    if (a=='?')
    {
      BT.println("Send 'h' to turn LED on");
      BT.println("Send 'l' to turn LED off");
       BT.println("Send 'b' to turn LED  on off");
    }   
  }
 }