two arduino cannot communicate via bluetooth

I used two HC-05 to do the job. Two bluetooth modules have connected successfully. However, when I try to use them to send data from arduino A to arduino B, it seems they have no response at all. My code is as follows:
transmitter

#include <SoftwareSerial.h>
SoftwareSerial BTSerial(10, 11); // RX | TX
void setup()
{
  BTSerial.begin(38400);  // HC-05 default speed in AT command more
}
void loop()
{
    BTSerial.write('1');
    delay(1000);
    BTSerial.write('0');
}

receiver

#include <SoftwareSerial.h>
SoftwareSerial BTSerial(10, 7); // RX | TX
void setup()
{
    pinMode(4, OUTPUT);  
  digitalWrite(4, LOW);
  BTSerial.begin(38400); 
}
void loop()
{
  if (BTSerial.available()){

   if(BTSerial.read()=='1')
    digitalWrite(4,HIGH); 
     
   else if(BTSerial.read()=='0')
    digitalWrite(4,LOW);
       
  }
}