Use add-on to connect a sensor other than a temperature probe

    I have a rain snow sensor that has two outputs - a relay that is off and that switches on when the sensor gets rain on it - see green/white lines in the attached wiring image.

    The other output is RS485A and RS485B - yellow/blue lines in the wiring image attached.

    I'm reading up about RS485 to see if what I need to do can be achieved. But would welcome any guidance.

    As it rains I'm assuming the voltage output changes the more rain there is on the sensor; and if it snows it outputs something to indicate snow. Not sure. But I was wondering if I use the Shelly 1 temperature sensor add-on, could I connect the rain snow sensor RS485A or S485B to the Shelly 1 temp add-on and use the output (which would show up as temperature change) to indicate the amount of rain I'm getting.

    Two images are attached, one is just a picture of the sensor. The other is the wiring outputs. I'm guessing that the Yellow or Blue line could be connected to the same wiring that the temperature probe would attach to on the temp add-on?

    The rain snow sensor operates on 12 to 24V - at least the one I have says this on the box.

    I realise I might be able to do this with the Shelly Uni. But I have a few spare Shelly 1 with the Add-On and thought I might as well use one of them for this.

    Bernard

    Wellington, New Zealand

    RainSnowSensor.jpg        RainSnowSensorWiring.jpg

    Unfortunately, the standard RS-485 defines the electrical characteristics of the interface only. Handshake and communication protocol is not included. Thus, the indication of „RS-485“ gives no information if this sensor would fit with the add-on of a Shelly 1 or Shelly UNI data port.

    Moreover, the supply voltage of the sensor, ranging from 10 to 30V DC seems to be very high compared with the regular temperature and humidity sensors at the add-on.

    Would recommend to use the contact only - or to try getting more information about the protocol at the data interface. Perhaps with an arduino or a similar unit an appropriate interface could be constructed…

    „Habt Geduld. Alle Dinge sind schwierig, bevor sie einfach werden!“ (aus Frankreich)

    „Nothing in life is to be feared, it is only to be understood.“ (Marie Curie, 1867-1934)

    „Es reicht nicht“, rief Schiller, „Gedankenfreiheit zu fordern, man muß auch denken können, sonst fordert man Gedankenlosigkeitsfreiheit und die ist die Freiheit zur Dummheit, welche wiederum die schlimmste Unfreiheit überhaupt ist!“
    (Aus „Besuch aus Weimar“ von Gert Heidenreich, Schriftsteller, *1944 in Eberswalde)

    Thanks thgoebel. Yeah from what I've read now, I can't use RS-485 when the Shelly. What I'll do instead is use the relay output from the rain snow sensor to indicate when it's raining or snowing which is a reasonable work around.

    Bernard