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maciek
maciek
Associate III
November 3, 2017
Question

USI WM-SG-SM-42 point to point communiation

  • November 3, 2017
  • 3 replies
  • 1581 views
Posted on November 03, 2017 at 15:02

Hello,

Using 2 WM-SG-SM-42 modules which are parts of I-NUCLEO-LRWAN1 I am trying to establish point to point communication without LoRaWAN. I have updated the AT commands firmware to 3.0 and I am following the examples in documentation.

On the transceiver I am writing commands:

ATZ // reset the module

AT+RF=15,869000000,7,0,1 // setting up the radio

AT+TXT=1,48454C4C4F // transmitting the data

On the receiver I am writing commands:

ATZ // reset the module

AT+RF=15,869000000,7,0,1 // setting up the radio

And I do not get any messages. I was of course trying to set receiver in listen mode (AT+DEFMODE=5) and in continous RX (AT+DEFMODE=3) and I can not get any +RCV messages.

Anyone has already established such connection?

#usi-lora #p2p
    This topic has been closed for replies.

    3 replies

    Tesla DeLorean
    Tesla DeLorean
    Guru
    November 3, 2017
    Posted on November 03, 2017 at 16:06

    I think you'd probably want to seek support more directly with USI.

    Most of the people I know are nuking the USI firmware and putting their own on the devices, and this case the modules can definitely send and receive to other nodes with LoRa (not WAN)

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    maciek
    maciekAuthor
    Associate III
    November 3, 2017
    Posted on November 03, 2017 at 16:12

    Hello Clive,

    I've started to test this module today- I have already run my contacts to get to the USI support. But it's Friday evening so...  Anyway, last time I was contacting them via my distributor they said it is possible to establish p2p communication and everything is decribed in the AT command manual. The documentation is very poor but I thought it is not so hard to do that. I gues there is some magic combination about which they are not writing.

    Btw- nuking the firmware and placing my own will not end with losing FCC certificate? Because we have decided to use this module only because of the FCC- otherwise we would use just transceiver.

    Tesla DeLorean
    Tesla DeLorean
    Guru
    November 3, 2017
    Posted on November 03, 2017 at 16:51

    To carry over FCC certification you'd have to also use exact same cables and antenna. At the board level you would need to be concerned with being an unintentional radiator.

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    maciek
    maciekAuthor
    Associate III
    November 6, 2017
    Posted on November 06, 2017 at 12:29

    I am aware of that we have to use everything the same. That is the plan. But for now we want to know if such communication is possible without LoRaWAN with these modules with certified firmware.

    maciek
    maciekAuthor
    Associate III
    November 13, 2017
    Posted on November 13, 2017 at 13:23

    Well, I've today received a phone from an engineer fromAcal BFi with a support. Apparently, USI does not write that before mode changing, the module has to be in IDLE mode. So P2P communication should look like this (quoting):

    'At Receiver,

    # ATZ /*Reset */

    # AT+DEFMODE=0 /*set toIDLE mode*/

    # AT+RF=20,868000000,7,0,1,0,8,0,0,0,0 /*set RF = 868MHz SF7/125KHz

    BW/CR1/CRC On/Preamble Length 8/No-IQ-Inverted/20dbm output power */

    # AT+DEFMODE=5 /*set toRXmode */

    At Transmitter,

    # ATZ /*Reset */

    # AT+DEFMODE=0 /*set toIDLE mode*/

    # AT+RF=20,868000000,7,0,1,0,8,0,0,0,0 /*set RF = 868MHz SF7/125KHz

    BW/CR1/CRC On/Preamble Length 8/No-IQ-Inverted/20dbm output power */

    # AT+DEFMODE=4 /*set toTXmode */

    # AT+TXT=1,48454C4C4F /* transmit 1 packet

    contains raw data 'HELLO' */

    At RX Event,

    +RCV=-1,5,48454C4C4F /* receive 1 packet contains

    raw data 'HELLO' */'

    Aaaand it works.

    Turvey.Clive.002

    ‌ You can upload their official firmware from their github repository.

    Tesla DeLorean
    Tesla DeLorean
    Guru
    November 13, 2017
    Posted on November 13, 2017 at 15:37

    Last I checked the downloads were of encrypted firmware, so not much use.

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