Hey Murph, if you need any help this is the right forum for this Hikvision Doorbell.Whoah! I just stumbled across this thread again after sometime. Am I reading this right? Onvif, rtsp, door chime triggering, and as of today, under $100? I guess I have to order it now.
***edit***
EZVIZ on the way to be delivered Friday.
A few pointers:
Take a picture of the back of the Doorbell before you install, it has your Password you will need later.
I would make sure you turn power off before install. I had my wife ring old doorbell while I was at Electrical Panel to find Breaker.
You will read a lot about transformers here and on the Net. If you have an existing Mechanical Chime most liking you will need to replace your transformer (common size is 16V/10VA, what you would need is a 16V/30VA to handle the load of the Doorbell and Mech. Chime when doorbell button is pressed. If you have a 16V/10VA you can try it first and if your Mech. Chime does not work or you barely hear it then you know to change it out. Best place to look for transformer is in your attic. There are several Youtube videos that could help. If you need help picking out the right one, we can help.
Other than the above you should be good. The Doorbell comes with three different wedge mounts. If you need something different we here have found a few different other options.