Thanks a lot, Robert, Amoque and comwarrior for your helpful replies.

Replies from Robert and comwarrior give me the following idea: Once the device wakes up from sleep, keep checking pin 24 (Status LED) of the BT module for high pulse width. If and when the pin is continuously high, it means that the connection with the phone is established.

Amoque, I am using Samsung Android phone and the app Tasker (or ITTT) has many uses and I am sure, I will be using it for one of my future projects.

Bala