HOW TO: Get notification of traditional door bell

[Ingmar]

I know this isn't a new thing to do, but I didn't find any project on here that made it work in this way, so here we go.

Basically this how-to enables you to get notifications (e.g. on your phone, depending on what you set up in the Domoticz notification settings) from your traditional standard old school door bell. To send the signal to Domoticz via 433Mhz (so you will need to have an RFXCOM unit connected to your Domoticz) i used the KlikAanKlikUit/ClickOnClickOff key chain remote that's on the market. This is to keep it simple In short, we're using the power of the door bell to trigger a relay which simulates pressing the button of the key chain remote. The total costs are about 20 euros.

What you need:

• KaKu key chain (click)
• Relay (i used something like this)
• Elco (I don't know the specs, but it looks like this)
• Diode bridge (I don't know the specs, but it looks like this)
• Some wires and soldering equipment to connect it all together

I don't know the specs of the diode bridge and the elco because my knowledge of electronics doesn't go that far. I went to my local electronics shop and told them I have 8v AC power and want to switch it to DC power using a diode bridge and an elco. I used what they gave me and it works

1. First get the key chain remote ready, I would say this is the most difficult part. Take the housing apart so that you only have the board in your hands. Then solder a wire to two points of one of the switches. The idea is that when you connect those two wires together, it is the same as pushing a button (because that is basically what you are doing by pushing the button). You can double check with a multi meter which points of the switch you can solder the wire to. Also already add a switch to Domoticz that gets switched by the key chain remote. I have the self learning code version of the key chain, so I first paired it with a normal KaKu receiver that I use for a lamp, just to get a code in the remote. Then in Domoticz you can add it as a switch. I find the "learn light/switch" button the easiest way to do this, you can find it at the switches tab. Once you added it to Domoticz, check your soldered wires by connecting them together. You should see the LED of the key chain remote light up, and the switch in Domoticz should be set "on" now. If that works, continue.
2. Locate your bell (the part that makes the actual sound) and connect an additional wire to both existing wires of the bell.
3. Connect the two wires coming from the bell to the two wavy icons of the diode bridge (see the orange wires below). It doesn't matter which one goes on which one because it is AC power (alternating current).
4. The bell works on 8 volts AC power (you can see that on distribution board/stoppenkast, where the bell unit is, in my case it was written on the bell's switch) but we need DC power to trigger the relay. The diode bridge does that trick for us.
5. To make the power after the diode bridge (which is now DC power) more stable we place an elco (electrolytic capacitor) see schematic below. The elco does have a + and a - so be aware that you connect it in the right way!
6. From the elco we connect the negative (black wire) to the (-) of the relay, and the positive (red wire) to both the (+) and the (s). The (s) is the switch or trigger wire but might be called different depending on the exact model you got. We connect the positive wire to both the (+) and the (s) of the relay because we want to power and directly switch the relay.
7. Then as last step we connect the key chain remote to the relay. On the relay you will see NO (normally open) and NC (normally closed), sometimes the remaining connector has some text as well. We want to connect the two wires (which you soldered to the key chain remote) to the NO connector, and the one without text. We DO NOT USE the NC connector. It doesn't matter which wire you connect to which port so that's why the wires have the same color in the schematic. We use the NO port because we want the circuit to be open if nothing happens (=the two wires not connected to each other), but closed when the relay switches (and by doing that simulate a button press).

Schematic

bel.png (176.97 KiB) Viewed 4997 times

If you did it all correctly Domoticz will switch the switch to ON when the door bell is pushed. To get the actual notification, and set the switch back off I'm using the following blocky script:

Blocky

blocky.JPG (38.7 KiB) Viewed 4997 times

To finish it off you can place it in a nice box. I still had a plastic housing which I now used for this, helped by my glue gun to fix it inside.

Good luck

[Ruudhoevenaar]

Hero!

This was exactly what I was looking for.

[twoenter]

Yeah looking good.

The links are dead, do you have some specs of the capacitor, relay and diode bridge?

[twoenter]

Found a solution myself. See my blog

Written in Dutch, you can use Google translate.
https://www.twoenter.nl/blog/domotica/d ... -domoticz/

[ronaldbro]

I did almost the same, but connected the relay to a GPIO and the old gong in parallel of the relay. This way I get the signal in Domoticz and still have the old gong working.

[jadijkstra2000]

Hi all!

I am working on my doorbell as wel... what I notice is that the doorbell switch is a "break" contact instead of "make".
That makes it a little more complicated.

I want to seperate the doorbell switch from the "gong" with Domoticz.
I already had an interface for that (MySensors), but, pushing a switch, then going through mysensors -> domoticz -> PiFace -> doorbell is not that efficient

The problem with PiFace is the inputs, even with pull-up resistors and elko's they are very senstiive.
What I want to make (and i have the test already), is to use an Arduino Nano with relay, which triggers 1 input on the PiFace, so less "levels" to trigger the doorbell

[ronaldbro]

I think it doesn’t matter if it is a make or break switch. In that case you can just react on the ‘open’ event and not the ‘close’ event.

[jadijkstra2000]

I think it does!

I don't want to have a relay always on, and off when the doorbell is pressed..

[kniazio]

This design can be done using two elements:
230V relay + Window / door opening sensor 433MHz
In addition, if you have a camera somewhere around the front door, you can do that by pressing the bell, the camera will take a picture and send it to the Telegram.
I have made such a system and it works great.