How to send more than 119 byte payload over AT commands

LPWAN Modules / EVBs RAK811
#1

I have a RAK811 development board I am interfacing with using AT commands over USB. I see in the RAK811_AT_Command_Manual_V1.0.pdf section 1.2 it says there is a 255 character limit for AT commands including the terminating characters.

The command to send data over lora is at+send=lora:#:<data>\r\n where # is a 1-digit port number. This takes 17 characters leaving 238 characters for the data which is in hex meaning an effective payload limit of 119 bytes.

At DR3 (SF7125K in USA) I should be able to send around 200 bytes. Is it possible to send payloads of over 119 bytes using AT commands?

#2

Dear,

This AT command is not support,

But you can send around 200 bytes by RUI port.

#3

Thanks Nicholas,

Can you point me to some documentation on using RUI?

#4

Dear，

You can refer this web,
https://doc.rakwireless.com/developer-tools/developer-tools/getting-started
Hope help you!

#5

119 bytes would be at the huge end of the LoRaWAN payload size. The average of my devices is around 16 bytes.

See https://lora-developers.semtech.com/library/tech-papers-and-guides/the-book/packet-size-considerations/ for some info.

Can you break your payload down, use different ports to differentiate the different payloads, send smaller packets of the faster changing sensors & the occasional packet of slower changing items. Or byte pack the data to make it smaller?