Ionic: How to send json data to paired device using bletooth serial

#1

sendData(){
this.bluetoothSerial.write(‘Hello world’).then((data)=>{

      alert(data+'for success writing data');
  },err=>{
      alert(err+'for error writing data');
 
 });

}
The above code always alert success But I don’t know is it sent or not…???
Please help its urgent