I don't have transformer in the circuit. To cut costs, minimum components are required and as this is an enclosed circuit, it is ok to not to have isolation.
I previously used this-----
From Mains - > 2.2M->12v Zener-> 4.7k -> 5V Zener -> 4.4M -> PIC. This worked fine for a long time, but now I want to make the circuit better and put full wave rectification, I tried the same above circuit but the voltage on PIC is sticking to 0.5 for some reason. So I would like to ask if I should make changes to the above circuit may be reducing resistance values or choose a completely different circuit.