Test ping/pong



  • Had some fun with a ping/pong test - use one LoPy on an expansion board via usb, serial in and start up this server code: (sorry, not enough points to upload a file :)

    0_1478567054349_server.py.jpg

    Then the other LoPy connected to notebook with wifi, on a breadboard w/ a single Lion cell - telnet in and enter this client code

    0_1478567292169_client.py.jpg

    Then you can carry the battery LoPy or the notebook around and see what kind of distances you can get in your neighborhood. Idea from radiohead rf95 client/server example.

    The full instantiation line is (US frequency):
    lora = LoRa(mode=LoRa.LORA,frequency=913100000,tx_power=14,bandwidth=LoRa.BW_125KHZ,sf=10,preamble=8, coding_rate=LoRa.CODING_4_5,power_mode=LoRa.ALWAYS_ON, tx_iq=False, rx_iq=False, adr=False, public=True, tx_retries=1)



  • No long distance tests yet. Played with some parameters and found these max working distance settings work around the house:

    tx_power=20 (US 915 band)
    bandwidth=LoRa.BW_125KHZ
    sf=12
    coding_rate=LoRa.CODING_4_8

    Changing BWto LoRa.BW_125KHZ results in faster data rate and in theory lower receiver sensitivity.

    Just found another great write up of LoRa modulation at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5038744/



  • This post is deleted!


  • @cswiger said in Test ping/pong:

    LoPy

    Thanks for sharing! Did you try a distance test at all?


Log in to reply
 

Looks like your connection to Pycom Forum was lost, please wait while we try to reconnect.