I have an automation which will turn of the light if there is no motion for 15 mins. However, if I sit in the soft, it will be triggered. I am using xiaomi motion sensor. I understand this is because the motion sensor didn’t detect the motion from me if I sit without any actions. Is there any more conditions or methods which can improve the detection?
You could use a bluetooth tracker to detect the presence of your phone. For example using http://happybubbles.tech/
By placing one “bridge” in each room, you can determine in which room each Bluetooth device is.
This, of course, only work if you have your phone with you, or a smart watch.
What are you doing while sitting? If you are watching TV, you could add a condition that only turn off the light if the TV is off. If the TV is on, you can assume someone is in the room. The same work with a computer (if you always turn it off or put it in standby when not in use).