Inconsistent packet uplink timing to Application Server

ChirpStack Application Server
1

Hi, I have been using a simple example code from Arduino IDE that sends “Hello World” as a payload from an RFM95 to the gateway, and then to the application server. The setup is a Raspberry Pi with a rakwireless Pi-Hat attached. The program is designed to send this message every 60 seconds. But it only seems to be sent very sporadically; sometimes it appears on the Device Data tab as an uplink every few minutes, sometimes it is an hour between uplinks, and sometimes it doesn’t seem to send any data at all, even after multiple hours.

I am using US915, so I don’t believe the EU 868 1% Duty Cycle restriction is imposed. Could it be the configuration files? I believe they are all correct.

I will include a screenshot of a bunch of uplinks from yesterday. One thing i noticed is that they are all on a frequency range of around 904 MHz, but shouldn’t they range from 902 to 915 MHz? Is my setup not using the full available spectrum, and that could be a reason why? Thanks for reading.

uplinks
uplinks1920×847 106 KB

2

I see a lot of packet-loss when looking at the fCnt values. As there are 64+8 channels in the US915 region, but your gateway only supports 8+1 channel, are you sure your device is using the correct channel-mask?

3

Hi, thanks for the response. I am not sure if my device is using the correct channel-mask, how would I go about checking that? This is my first time using LoRa, so there are a lot of new things for me to learn.

4

That depends on which LoRaWAN stack you are using on your device…

5

I am using the MCCI LoRaWAN LMIC library. The sketch I used was called ttn-otaa, but from my understanding it could be used for ChirpStack as well.