I have a RAK811 WisDuo in LoRaP2P mode and i’m trying to send a 72 character payload with the following configuration:
64 Symbol Preamble
12 Spreading Factor
4/8 Coding Rate
Config command being: at+set_config=lorap2p:869525000:12:0:4:64:20
I’ve found that the RAK will crash and hang, failing to send a packet acknowledgement “[LoRa] P2PTxDone.” when sending a packet larger than 10 characters at 64 preamble.
Note that when I set the preamble to 40, i can send 40 characters.
I think i’ve tracked it down to the base RUI API that’s causing this. The “rui_lorap2p_send” function call at line 327 here (https://github.com/RAKWireless/Products_practice_based_on_RUI/blob/master/based%20on%20RAK811/app_RAK811/at_cmd.c)
It seems to be some sort of overall packet length thing, as when i shorten the preamble, I can send a larger message.
Could someone inform me whether there’s a fundamental reason why this isn’t possible with LoRa or is this just a bug with RAK firmware?