Is there any doorbell out there that can work as sonos doorbell

You could probably do it with Smartthings fairly easy and a home connected doorbell.

one person even did this so their ordinary doorbell triggered smartthing event https://community.smartthings.com/t/a-simple-way-to-get-alerts-when-your-doorbell-is-rung/6027

MTI,
Our Sonos Gateway has lots of features:

Doorbell:
- Determines all sonos devices in the broadcast network.
- Plays the doorbell to sonos speakers named as ANYNAME-DB (-DB is the indicator for playing the doorbell on this speaker. If the speaker is grouped with other speakers the group will play the doorbell)
- It plays one of ten default or custom uploaded mp3 files at the desired volume (either set in the UDP packet sent to the gateway or set on the gateways webinterface as an "override" feature)
- Triggering the doorbell stops the radio station, playlist etc. which is currently played on the -DB sonos speakers, plays the doorbell sound and fades in the previously played track again.

Alarm-Sound:
We have also an alarm feature built in. This we use to play an alarm sound preferred at full volume on all sonos speakers.

Play, Stop and Volume
Then you can start stop and volume up down all the speakers with udp commands (this works currently for all speakers, per zone will be released in about six weeks)

All the features can be triggered with UDP packets (following a simple protocol) which are sent to the sonos gateway.

A simple video of Lextend is available under...
https://vimeo.com/164429234

Segger,
Will the doorbell feature work with grouped players as well?

MTI,
Yes, If at least *one* player in the group has "-DB" in the loudspeaker name. The whole group will play the doorbell sound.

If there are many groups:
All groups with at least *one* loudspeaker containing "-DB" in the name are grouped, then played the doorbell and then split again to the original groups.

I will post a video on that later on our vimeo channel.
https://vimeo.com/user31912943

Segger,

This is exactly what my clients are looking for. Our techs are not Python experts, do they need to be to implement this solution for a doorbell?

MTI
No IT skills are needed for Lextend. It needs do be installed on a cap rail and connected to the ethernet (Same IP Network as the Sonos speakers).
The Sonos loudspeakers are discovered automatically and the settings are made via a web GUI and with the naming of the Sonos speakers in the Sonos App.

I was thinking about this yesterday and and it would be rather simple with Flic + Raspberry Pi + SoCo

Requirements:
Flic button (http://flic.io)
Raspberry Pi with Bluetooth dongle or Raspberry Pi 3

I can make a sample script which can work as a doorbell this weekend.

Asturaz,
Ringing the doorbell sounds easier than is seems. You need to group the speakers that the doorbell is played in sync.
Then if you have many groups you need to save the currently palyed track, playlist etc.
There are many use cases with Sonos to consider, especially if speakers are grouped and playing independent tracks, radio stations etc.

Flic is a nice idea. Can flic send UDP packets to a RPi? Our RPi solution does already quite advanced things with Sonos.

Advanced Doorbell:
https://vimeo.com/165879744

Sonos Zone/Group dependent features (play, stop, volume etc.)
https://vimeo.com/165882411

Annoucement features (Grouping all speakers and switching to a LineIn) etc.