To back up a minute, there seems to be some confusion about what RF means and what it’s used for…
RF = RADIO FREQUENCY
Zwave, Zigbee, and Bluetooth are all RF protocols. (RF just means “radio frequency.”) This is why devices using them in the US have to have FCC certification before they can be sold. They broadcast on a radio frequency.
There are many other radio frequency protocols used in home automation, including Insteon, X10, the Honeywell/Ademco frequency, Lutron Clear Connect, etc.
For that matter, WiFi is also an RF protocol.
OPTIMAL VIDEO DOORBELL NETWORK PROTOCOL
All the video doorbells I’ve seen, including Skybell, Ring, and Canary, are using WiFi for the simple reason that’s it’s one of the best for video. Zigbee and Zwave are intended for very small message packets on fairly low traffic networks where it’s OK if the messages sometimes arrive out of sequence. So perfect for “turn light on,” really lousy for streaming a movie.
OPTIMAL DOORLOCK NETWORK PROTOCOL
Doorlocks, on the other hand, don’t do well with WiFi because WiFi takes too much battery power. Lockitron found this out when some of their customers were having to change batteries every 2 weeks. So their second generation lock, the Bolt, uses Bluetooth instead.
SMARTTHINGS, HOWEVER, IS NOT A PROTOCOL
There also seems to be some confusion about what SmartThings is. SmartThings is NOT a proprietary system. It is certified for both Zwave and Zigbee. So it can talk to any certified zwave lock or zigbee lock (although maybe just to lock/unlock).
If you design a certified zwave lock, it will likely work with SmartThings, you don’t have to do anything special to make that happen.
HOW CAN YOUR DOORBELL TALK TO YOUR DOORLOCK?
OK, your doorbell optimally needs WiFi to run its video. And your doorlock optimally needs not-WiFi. (We’ll leave it open for now as to whether it should be zigbee, zwave, Bluetooth, or something else.)
How and why would they talk to each other?
Most commonly, I’d guess, would be for the human viewing the video to decide to unlock the door.
Lots of systems offer that option already, by the way. Iris, Staples Connect, and GoControl all have WiFi cameras in their systems. It’s no big deal. The person sees the video, then tells the zwave doorlock to unlock via the hub. This is exactly what hubs are good for–providing access to multiple network protocols from a single UI.
And when it comes to unlocking doors, well, it’s hard to think of a higher security need than that! Going through the hub allows for encryption and a network key, so nobody else can bring their device to your house and unlock your door that way.
You could bundle a doorbell and a doorlock together and just have them talk to each other and no one else. But as soon as you do potential customers are going to be asking why they can’t tie into their automated lights and alarms and motion sensors. So why limit yourself?
If there is something about your video doorbell which is unique and interesting enough to succeed on kickstarter, I wouldn’t worry about the doorlock. Or zwave, zigbee, or Bluetooth. Just make a great video doorbell with a published WiFi interface for other home automation systems and leave it up to them to decide how to integrate with you.
Engineering a good door lock is really, really hard. Seriously, hard. I wouldn’t get anywhere near that unless you absolutely have to. It will make zero difference to you what protocol is running the door lock security as long as there is some way to interface with your device through a WiFi bridge.
Just my own opinion…