Maximum distances between node and gateway with radio RFM69HW chips



  • I searched the forum on maximum distances, but didn't find much information about it.
    I know that distances can be influenced by concrete walls, steel, …, but what are the average distances you are getting with this radio RFM69HW?


  • Mod

    @evb I think I have seen 20m indoors with thick walls to 500m outdoors with no obstructions.



  • @evb It depneds on the attenuation of the signal path as @mfalkvidd pointed out, and to a lesser extent the version of 433/868/915Mhz selected. There is also a higher power version of this series, but with no additional preamplification stage from memory, but it should lift signal levels in borderline cases.
    Generally higher frequencies are subjected to higher attenuation, RC structures have higher attenuation than say timber frame. If you require extended external range you might consider a repeater with a better signal path (in the eaves with only timber in the way etc..).
    Pretty sure I saw at least one published range test on the internet carried out in an urban environment, and somebody on this forum published an rfm portable tester project to verify signal strengths, which may be worth looking into...
    I have no problems at all up to the 20m limits of this place with standard power 433 through two/three RC/Brick walls.


  • Hardware Contributor

    RF performance depends a lot on what's the setup

    • antenna shape (coiled/meandered less efficient, or straigth one), orientation, radiation shape, size, tuning (inside final enclosure might be different, good to check rssis and adjust if needed), quality (lot of bad/untuned on some ebay/Ali shops)
    • GND plane size,
    • software settings
    • the test environment
    • etc

    for example, here I use 868mhz. I have a compact outdoor RFM69CW node with a simple homemade coiled "wire" antenna (RFM69CW has lower TX power, no power amplifier) sending well at 45-50m from the house, and the RFM69HCW gateway (with power amplifier) is indoor. One thick wall and some trees. Elevation of both ends/antennas is 1.5m, default software settings (for bitrate etc).

    But in direct line of sight, outdoor, there are also people reporting up to 1-2km range.

    Compared to MySensors on 2.4ghz, it can be easier to get reliable indoor link with subghz.
    Like in case you would already have others protocols on 2.4, with wifi and expanders, zigbee, ble, mysensors is not yet resilient to interferences and overlapping freq with these others protocols.. (no frequency hopping for example). It means, 2.4ghz needs more care, and depends on long term evolution of your network..


 

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