HowTo: Node Red – Integrate 433Mhz SOS button

In the article about the 433Mhz mini push-button I have already reported on my forays into the wonders of the electronic product world. I also noticed a 433Mhz SOS button, which actually belongs to a wireless alarm system. Conveniently, however, its radio messages can also be sent with the RF-Bridge and thus use them to control our SmartHome.

How this works and what you have to consider is explained in the following article.

Safety instructions

I know the following notes are always kind of annoying and seem unnecessary. Unfortunately, many people who knew "better" have lost eyes, fingers or other things due to carelessness or injured themselves. Data loss is almost negligible in comparison, but even these can be really annoying. Therefore, please take five minutes to read the safety instructions. Because even the coolest project is not worth injury or other trouble.

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Helpful articles:
Of course, NodeRed should already be installed so that you can use this configuration. In addition, the Sonoff RF Bridge should already be prepared.
How to prepare this and a RaspberryPi for it and then install NodeRed on it is described in the following articles.

The following articles describe what you need to do to get everything ready:
RaspberryPi – setup for nerdiys!
RaspberryPi – The first configuration!
RaspberryPi – Control the RaspberryPi via SSH

NodeRed – Installing NodeRed on the RaspberryPi
NodeRed – Install new nodes
Sonoff 433Mhz RF Bridge with Tasmota Firmware flashing

Required material:

Required material:

In the following list you will find all the parts you need to implement this article.

Log into the NodeRed configuration interface

Before you can edit your NodeRed configuration, you must - if activated - first log into the NodeRed configuration interface.

View of the login dialog. Here you have to enter the login data that you specified during the configuration of the login. You can find information about this in the article NodeRed - set up user login.

The SOS button

The SOS button basically looks like a small donut. It comes with a strap which makes it perfect for wearing around the neck, for example, so that it is always ready to hand. The button is activated via two blue buttons on the outside of the "donut". These buttons light up three times each time they are pressed.

The donut-shaped SOS button incl. strap.

Import node code

The following NodeCode is similar to the code used for the Window contact, Wall switch or Mini pushbutton is used. It triggers an action as soon as a radio message with the appropriate data field is received via the Sonoff RF Bridge flashed with the Tasmota firmware. You can accept the code in this way, but you still need to set the RF code of your wireless pushbutton. This is described in the next step.

Of course you also have to update the configuration for your MQTT server and if necessary the topic under which you receive the RESULTS of your RF bridge.

Node code overview
[{"id":"7efc90e1.9792e","type":"function","z":"169c0bb.fea38f4","name":"Button-Press detected","func":"if (msg.payload.RfReceived!==undefined)
    if (msg.payload.RfReceived.Data==="RfCode")
        return msg;
}","outputs":1,"noerr":0,"x":840,"y":3860,"wires":[["459f01f5.ea95e"]]},{"id":"459f01f5.ea95e","type":"debug","z":"169c0bb.fea38f4","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","x":1070,"y":3860,"wires":[]},{"id":"952dc65.594ec38","type":"comment","z":"169c0bb.fea38f4","name":"433Mhz-SOS-Button","info":"","x":430,"y":3780,"wires":[]},{"id":"9c8b57a0.f0cd48","type":"mqtt in","z":"169c0bb.fea38f4","name":"","topic":"tele/RfBridge/RESULT","qos":"2","broker":"c94e86db.dfcde8","x":440,"y":3860,"wires":[["cf3b14b5.f67058"]]},{"id":"cf3b14b5.f67058","type":"json","z":"169c0bb.fea38f4","name":"","property":"payload","action":"","pretty":false,"x":640,"y":3860,"wires":[["7efc90e1.9792e"]]},{"id":"c94e86db.dfcde8","type":"mqtt-broker","z":"","name":"Server-Mqtt","broker":"","port":"1883","clientid":"","usetls":false,"compatmode":true,"keepalive":"60","cleansession":true,"birthTopic":"","birthQos":"0","birthPayload":"","closeTopic":"","closeQos":"0","closePayload":"","willTopic":"","willQos":"0","willPayload":""}]

Reading out and setting the correct RF code

In order for the above-mentioned node code to work, you must set the RF code of your wireless push-button. This RF code is a unique ID for each push-button and is also different for each push-button.

Open the console of your RF-Bridge. Here you will be informed about current events on your RF-Bridge. Among other things, received RF codes are also displayed there.
As soon as you press your SOS button, the radio message sent by it, including the RF code, is displayed in the console of your RF bridge. You must now copy/remember this RF code (marked in blue in the screenshot), as you must now enter it in one of the imported nodes.
To do this, switch to the Nodered configuration view and open the menu for the "Button-Press detected" function node. There you replace the part RfCode by your previously memorized RF code.

After that click on Done, sends the changes to the NodeRed server and from now on you should get a notification via the debug node every time you press the button.

If you don't receive any, please check if you need to update the topic under which you receive the RESULTS of your RF bridge.

Have fun with the project

I hope everything worked as described for you. If not or you have questions or suggestions please let me know in the comments. I will then add this to the article if necessary.
Ideas for new projects are always welcome. 🙂

PS Many of these projects - especially the hardware projects - cost a lot of time and money. Of course I do this because I enjoy it, but if you think it's cool that I share the information with you, I would be happy about a small donation to the coffee fund. 🙂

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