I bought the R503 fingerprint sensor which I have connected it to my Raspberry PI. I’ve chosen not to connect it with ESP32 because I already had installation going to my Raspberry, so I didn’t have to drill a new hole on my wall.
The easiest way to mount it is to use an old CD/DVD and widen the hole in the middle.
I’ve released a service for Raspberry which communicates through MQTT messages with the fingerprint sensor and it works flawlessly till now. I highly recommend it for unlocking the door.
You can find it in my github repository here.