Smart Doorbell

This page shows some solutions to get a smart doorbell with some nice features, like sending a photo to smartphones by Telegram.

Using a Creasol DomBus23 module to convert a simple "analog" door bell to a smart doorbell

Interfacing an existing doorbell to Domoticz is really simple, in both hardware and software.

The schematic above uses an optoisolated input of the DomBus23 module, connected to the door chime: DomBus are modules designed to be reliable (connected by wire bus) and very low power (less than 10mW in stand-by), but of course any module with an opto input can be used as well.

When the door chime is supplied (doorbell button pushed), Domoticz will execute a script that grab a snapshot from the IPcam and send it by Telegram to a group of channel within the family members. This is the configuration of the doorbell device in the Switches panel:

As shown in the picture, when doorbell is activated the sendsnapshot.sh script is called, which grabs the picture and sends it by Telegram using the sendTelegramText.sh script.

The first script can grab directly a snapshot if the IPCam supports this feature; for bad chinese low-cost cams that do not support this feature, it grabs a snapshot from the RTSP media stream: this operation is not immediate, but takes 3-4 seconds to get the snapshot from IPCam. From the snapshot, then it's extracted an area of your need, to get the best picture with best zoom. The result is a picture like this, with information about the date/time the doorbell has rang.

Scripts and more info are available at https://www.creasol.it/smart_doorbell