Using frame logging to receive plain LoRa messages

ChirpStack Network Server
1

Hi, New to ChirpStack and hoping this is the right place to ask for some guidance.

I have a I have this Raspberry Pi Hat which I believe is the RAK2245. I have set up the gateway successfully with Chirpstack.

What I’d now like to do is read sensor values from this moisture sensor. It does not support LoRaWAN. My understanding from that wiki is the values are sent as unencrypted LoRa messages.

I have tried changing the Chirpstack config to gateway_frame_log_max_history=1 to try to log all messages to Chirpstack but never saw any messages come through.

  [monitoring]
  bind="127.0.0.1:6379"
  gateway_frame_log_max_history=1
  per_gateway_frame_log_max_history=10

When I unplug and plug in my soil monitor, I don’t see anything happen in the ChirpStack logs or in the redis-cli monitor.

Any suggestions for how to troubleshoot?

Thanks for your help,

Mike

2

You’re confusing LoRa with LoRaWAN - the most excellent explanation of LoRa is to be found here. Go read it & watch the short video, we’ll wait. For homework, I require you to watch this 30 minutes video which explains why LoRa is so cool; there will be a quiz later, so pay attention!

So, to recap what you just watched, LoRa is a spread-spectrum protocol patented by Semtech to transmit low bitrate data with minimal power over huge distances. You need a SX12xx chip on both ends of this distance and a microcontroller to move data around. That’s it to use LoRa - plug and play.

ON THE OTHER HAND, LoRaWAN is a Wide Area Network stack that goes over LoRa that allows secure communication and Over The Air Authentication. In addition to SX12xx chips, any sort of security requires use of KEYS.

Quick sanity check:
Q1: does the sensor come with a 64-bit DevEUI and a longer AppKey (in the form of a QR code or a sticker, say)? If so, could be LoRaWAN; go to #Q2. If not, something else and you’re on the wrong forum.
Q2: do you need to register sensor’s DevEUI and AppKey BEFORE reading any values anywhere? If yes, it’s most likely LoRaWAN. If not, you’re on the wrong forum.

You need to obtain a matching SX12xx chip & mate it to a LCD or serial port to see your data - read the part after “Next, it will show you 3 LoRa receivers to receive the senor measurement” more carefully.

3

Ok, thanks for the engagement. I’m certainly sold on the potential of LoRa. The detail there has new stuff to me, but the big picture of the difference between LoRaWAN AND LoRA I had figured out. I was hopeful that Chirpstack could log all network frames with this

gateway_frame_log_max_history=1

setting (documented [here](https://www.chirpstack.io/network-server/features/frame-logging/)) and that would include LoRa “frames” – but I didn’t understand that LoRa messages wouldn’t be considered frames.

I have [this](https://www.adafruit.com/product/4074) “bonnet” on a different Raspberry Pi. It has a SX12xx chip on it. I haven’t gotten it to work either but I will keep trying. Again, I’m sold on the potential. But, plug and play is not a term I’d use to describe LoRa or LoRaWAN.

4

Given that they’re two very different things, no, they aren’t meant to plug and play with each other.

If you want the raw frames, just subscribe to the raw gateway traffic topics of the MQTT broker and get them the same way that chirpstack does. But you’ll only find anything if the node is using the exact same LoRa air settings as the LoRaWAN traffic that the gateway is setup to receive - which there would be little reason for them to.

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