Hello@jemish Yes, it is possible to create a smart water level detector for your home water tank using an ultrasonic sensor or a float switch connected to a microcontroller with wireless connectivity.

I use Abloy EL582 and with that you can either set it to be open as long as 12V is applied, or closed as long as 12V is applied. Simple as that. I control my doors with a KNX switch. If you go with a lock like this and have the door closed when no power is applied be ware that you need a key to open in from inside in case of fire.

@jemish , There are thousands of locks out there which can be controlled by electricity - several examples have already been given to you. Why dont you go and research the hardware lock you think will work for you and your door and come back here with the link to it, and we can help you to control it with mySensors.

if I logout the my.openhab.org account and stop openhab on raspberry pi then also open the UI application. what is the reason behind that?