Check if bluetooth device is connected or not

hi , i'm working in project to collect data from sensors with bluetooth (data : json) , and i want to get status of bluetooth device is connected or not , i have data gathered from sensors or not .. the data json still the same if i disconnect if device so can't judge if bluetooth connected or not .

What node are you using? What does your flow look like?

i'm using serial port of node red

And what module do you have connect to the serial port?
Link/pdf?

module bluetooth HC-05 , i'm alredy connected to it and i have the data