Repeater Node via Ethernet?

  • Hi,

    got problems with my Mysensors architecture. I'm living in a house with 3 1/2 floors. The controller, Domoticz on a Raspberry Pi and the Mysensors Ethernet gateway are on the top floor. The devices furthest away are in the cellar, some are outdoors. In order to reach my devices I've introduced repeater nodes, one on the top floor right outside the room with my controller/gateway. One two floors down in the cellar [side question: the idea is that the repeater in the cellar will connect to the repeater on the top floor which then connects the both of them to the gateway. Will this work at all? Has anyone got this running?]. Now, connection to these repeaters are happening rather infrequently: I've implemented simple clients in my repeaters which toggle a switch every few minutes the value of which is sent to the controller. Sometimes this value is updated correctly, sometimes there are long gaps. I'm using the antenna version of the nrf24 modules and robust power supplies. I've added condensators to the radio modules. As I said, sometimes it works, sometimes it doesn't.

    Since using this for a reliable system doesn't make sense/won't work I'm looking for other means to connect to my sensors. Since I've got "Ethernet over powerline" in the house I thought about creating a long range connection between gateway/controller and repeater nodes via Ethernet and then connect sensors locally via nrf24 modules. Could that be done? HAS anyone done that? What do I need for that?

    Help anyone? I'm losing patience finally 😉 Two weeks ago I got a new gas meter which now COULD be connected to Mysensors and I can't get myself to do that because what's the use if I can't GET the data then?


  • Mod

    Multiple repeaters in a chain is supposed to work, so your 2-repeater setup should work as long as the sensor can communicare with a repeater and that repeater can reach the next repeater and that repeater can reach the gateway.

    Repeaters repeat the message on the same media type. So a nrf repeater repeats the message on nrf. If a node is able to forward messages on ethernet, it is called a gateway. You can have multiple gateways. So a simple soultion would be to add an ethernet gateway in the cellar. See for a description of the difference between repeaters and gateways.

  • @mfalkvidd

    Let me get this straight: I could build another Ethernet gateway, place it in the cellar and my MySensors sensors would happily connect to it? What would be it's ID (my gateway right now is "0" of course) ? Won't the two gateways puzzle those sensors that can actually see both?
    Have You done this?

    Thanks. Very interesting.

  • Mod

    @hyla yes, you are correct. Both gateways would have id 0. You are correct that this could confuse the nodes that can see both. You would have to use two radio channels, one for each gateway, and program the nodes with the frequency of "their" gateway.

    I have not tried using multiple gateways myself.

  • @mfalkvidd

    I have never tested this either but wouldn't it be better to make the second gateway and ID of 1. Both gateways could talk to the controller and remain on the same frequency. The nodes would pick whichever gateway they could talk to.

    If you change frequency on the second gateway, if you had a portable device (such as a keyfob) it would only work with one of the gateways.

  • Mod

    That might be better, but then you would have to modify the MySensor routing code to handle delivery to either of the gateways (or handle it manually in the node sketches somehow).

  • Okay, tried it today (with very little time). I found that inspite of changing the channel (from 76 to 77) all of my devices were listed under the new gateway.
    I then removed them all and after that I got the one device I had the channel changed on. But also one where I hadn't. I'll have to look into that again...
    In Wireshark I get messages on both channels but the one changed to channel 77 has got a "?" for the source. Is that supposed to happen? Anyway I'd have expected not to receive stuff for the other channel at all...

    Still, all very promising 🙂


  • Mod

    The channel width of the nrf is "less than 1MHz" when using 250kbps according to the preliminary specification. At 2mbit the width is 2MHz. Increasing/decreasing the channel with 1 will move the center of the channel 1MHz. Maybe separating the two networks with more than 1 channel is required?