Peer-to-Peer

[Danny Weng]

Can we use xDot to do the same thing as mDot?

mDots using version 1.0.8 (or later) AT Firmware or Library can be configured for peer-to-peer communication. Configuring two or more mDots with the same network settings allows communication between them. Enabling ACKs guarantees packet deliver; however, this may disrupt higher level protocols such as zmodem or ymodem file transfers. Communication between mDots is half-duplex so both ends should not transmit at the same time, otherwise communication will be disrupted.

The frequency can be set for US 915 models. We advise using 915.5-919.7 to avoid interference with LoRa Networks.

In Europe, use a fixed frequency, 869.85, with 7 dBm power setting to allow 100% duty-cycle usage.

[Steve Kovarik]

Hello Danny

Yes, both the xDot and mDot were designed with the same functionality.
The xDot also works in peer-to-peer mode of operation.

-Best Regards

[Danny Weng]

Hi Steve,

Thank you for your response!

Best regards

[Tito Sanchez]

I am having an issue with reliable peer to peer communication. I am would like to have multiple node xdots wake up then send data to a single base xdot. I followed this guide https://www.multitech.net/developer/software/mdot-software/peer-to-peer/
But something seems wrong. with node 1 talking to base xdot it works well. But node2 to base communications seem difficult. I can get a message through with node 2 but then after that it does not talk to base again. If I send a message from node 1 to base it works. Then I try node 2 again, and it will work for a single message.

I turned off message repeates and message acks. I tried changing up link counter on nodes to make sure it was not that causing issue. Not sure what elese to try. I am using AT command firmware on all xdots. For base xdot I enter at+sd to go to receive mode. For the nodes I use the send command at+send=data.

Here is the way i setup all xdots:
AT+NJM=3
AT+NA=00112233
AT+NSK=00112233001122330011223300112233
AT+DSK=33221100332211003322110033221100
AT+TXDR=DR8 (US:DR8-DR13,EU:DR0-DR6)
AT+TXF=915500000 (US-ONLY:915.5-919.7)
AT+RXO=1
AT+ACK=0
AT+REP=0
AT&W
ATZ

[Jason Reiss]

Peer-to-Peer

If more than two modules are used for there will be lost packets if the same FCNT is sent from devices. The module will report only FCNTs that are different than the last received in case AT+REP (repeats) are enabled. Setting each sending device to start at a different FCNT with AT+ULC should allow many devices to be received received. DOT1 – AT+ULC=0, DOT2 – AT+ULC=1000, DOT3 – AT+ULC=2000, etc.

[Tito Sanchez]

I followed the guide at this link “https://www.multitech.net/developer/software/mdot-software/peer-to-peer/” exactly including changing the uplink counters. The behavior is the same.

I am using this firmware “xdot-firmware-4.1.20-US915-mbed-os-6.8.0.bin” is this correct for my US model MTXDOT-NA1?

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