Lopy over Lopy by Lora

  • I am trying to connect Lopy over Lopy by Lora using the example.
    But this also only works at a very small distance, i.e. only when they are next to each other. If I walk 1 meter away from it, it won't work anymore. Both have a connected antenna.
    Software Pycom MicroPython 1.18.3 [v1.8.6-849-e0915e1]
    on 2019-10-06; LoPy4 with ESP32
    Does anyone know what could be the cause?

    Translated with www.DeepL.com/Translator (free version)

  • Found the error, I had chosen the wrong antenna site. Now it works.
    Thanks for the food for thought.

  • @Wolli01 What I am missing in the example you pointed at is to set the frequency. The sample scripts I use set it specifically, like:

    lora = LoRa(mode=LoRa.LORA, frequency=868000000, region=LoRa.EU868)

    If two devices do not work at the same channel, there may still be some spurious reception on an adjacent channel.

  • I have now taken a brand new Lopy4, but the problem is always the same. On a short distance it works but from 1 meter on no more data comes.
    Is there a Lopy to Lopy code that works in any case?
    Do you actually not have to enter an identification?
    What is another Lopy from any other Lopy comes into play then I receive unintentionally also its data or?

  • @Wolli01 receive up to 64 bytes.

  • @robert-hh
    In a normal Lorawan via a gateway, the two Lopy4s work perfectly. How long can the transmission text be?
    What is 64 for with s.recv(64)

  • @Wolli01 I have more the opposite problem, that at short distance the signal levels are too high. So when doing that, I uses a 50 Ohm termination resistor instead of an antenna. The stray radiation from the board & the pigtail cable is still strong enough for lab desk testing. If you have LoPy4, check that you use the right antenna plug. They are different for 433 and 868/915 MHz.
    You problem may have another cause: I found the Lopy-Lopy sample code not very reliable. And you have to take care to give both devices a fresh power-up start. Soft reboot does not initialize the Lora modem properly.

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