CubeCell Arduino BMP280 example misses replies

#1

I’m testing the Arduino LoraWan_BMP280 example with a Laird RG1xx gateway and TTN.
It seems to work fairly well, except that the CubeCell PCB seems to miss a lot of the confirmation downlink packets, regardless of how close it is to the gateway.
Being fairly new to this LoraWan stuff, I’m trying to understand the sequence. Does TTN have to respond to the Laird gateway, which then sends the confirmation downlink message, or does the gateway respond immediately, without regard to the TTN link?
I ask this question because I’m wondering if it’s a timing issue, i.e. is the CubeCell closing the RX window too soon?

Thanks for any light anyone can shed.

John

#2

Hi
The gateway is in effect passive, it forwards to TTN and receives messages from TTN such as join confirmation, ACK and ADR etc.

I have not had an issue with the RX timing windows RX1 or RX2 . I use TTIG gateways, this does not always work, but that is because the session is disconnected by TTN if its not used in 30 second and then take a few second to restablish the session.This can cause an issue with join acknolodgements on initial join. Check your using the latest Cubecell Board manager 0.0.4 and sketches…

Simon

#3

i have now 16 gateways online and working flawless
all are using the mikrotik lora8 card.

#4

@sivaelid: Yes, I am using the latest.
So how can that work? The End Device has strictly timed RX windows, from my reading of the spec, and the Internet latency varies enormously(in my neck of the woods). Sorry if I’m being dense, but I really don’t understand how that could work reliably.
.

#5

Hi the rx1 and rx2 Windows are 1 second and 2 second after the end of the uplink transmission. The node then listens for response messages e.g ack ADR etc. If TTN sends response then the gateway passes that for RX1 at the frequency the node transmitted on. For RX2 it transmits on 869.525MHz at SF9 at higher power. Due to the time windows this takes account of network packet delay and time errors. This is all described in the TTN site under. /Learn/Network info.

Hope this help understanding

Simon

#6

OK. I’ll read up on that tomorow. My experience to date has largely been with Google Sheets, which sometimes seems to take an age to respond.
Thanks.

#7

Hi no probs TTN learn section is online and a good knowledge source but focused on TTN. Otherwise the detail is in all the specs on the Semtech site good for the fine detail. it’s good also look at the community forum on TTN. It’s just like this one but for all equipment types and systems.

Simon