I'm trying to get a notification on my main phone or email when someone rings my doorbell, without changing the doorbell. The sound is loud, so I'm thinking to set a secondary phone next to the intercom speaker, that would notify me once the dB level is higher than a certain threshold. Do you guys have any idea of how I could do this? Cheers!
An option that one might consider "off-the-shelf" would be If This Then That, a web based service that uses internet connected devices (among other things) to provide responses to physical actions.
Your request could be as simple as a branch off your doorbell circuit that triggers one of the many network-capable devices to signal IFTTT to send a text message or email.
I did a quick search on the site for doorbell and got a bunch of results that may be of value, depending on your technical skill and budget. Even if one is not a perfect match, it may provide a path to a suitable solution.
Another option is called Blynk. It provides similar capability, based primarily on network-capable devices and one's cell phone. I was not able to find a search option in the site and did not sign up to investigate further, but the blog posts I receive from my Kickstarter contribution indicate that this service is also capable of solving your objective.
Since you & your brother are able to code, I will offer a software and hardware solution, which could be fun hobby project.
I plan to do this some time soon, with a difference to you (but you might change your mind & do my project ;-)
I am going to use an ESP32 (kinda like a smaller raspberry Pi, without Linux). They are well supported, with over 100 million sold, cheap, programmable and have both BlueTooth and WIfi.
I really like this one, because LilyGo is a good brand. It costs about $17, which is a snip for something programmable and internet enabled.
It has a camera and an LCD display screen, which means that I can use it for two way communication. Wifi on the board is simple to program, to alert me when the door rings.
There are good code samples to be had, so that you don't need to re-invent too much of the wheel. In fact, if you search for
esp32 face recognition, you can even have that if you want.
BUT, since you say
I'm trying to get a notification on my main phone or email when someone rings my doorbell, without changing the doorbell.
Then all you need is a much cheaper ESP32 with no camera or LCD display, just a microphone (they are all internet enabled), which should costs about $5.
You can code them in C or Python, as you prefer; there are plenty of examples and forums. If you are interested, you might want to know about our Internet Of Things sister site.
And, once you can code an ESP32 with a microphone, you can make your own Alexa for five bucks. Just search for
esp32 voice recognition (for instance, this).
I may have missed the mark, or I may just have gotten you a new hobby. I know that I got bitten badly :-) Please let me know what you think ...