Multitech Conduit Setup Assistance

Setup and configuration
1

Hi

I am having an issue setting up the Multitech Conduit with the ChirpStack gateway bridge.

I am a bit new to LoRa / Linux so I will try describe this as best as I can.

The goal is to connect LoRa devices to the Multitech Conduit and then forward the data to the Google Cloud Platform (GCP).

I am using the following links as reference:
https://cloud.google.com/community/tutorials/setting-up-loraserver
https://www.chirpstack.io/gateway-bridge/gateway/multitech/

In Short:
If I follow the instructions on the Chirpstack website for the setup of the gateway, I can connect to GCP and even subscribe to a MQTT topic on the GCP, but I have no idea how to connect my LoRa devices to my gateway.

I always start by erasing the entire mLinux image and clearing all the settings.
Then configuring everything from scratch after updating the image.

Using mLinux 5.1.8 base image & MTAC-LORA-H-915

Situation 1:

  • Installed Multitech Lora Network Server
  • Installed Multitech Packet Forwarder
  • Installed ChirpStack Gateway Bridge

In this situation, my device can connect to the LoRa network, but the gateway bridge does not subscribe to the MQTT topic on GCP (It connects to GCP, but doesn’t proceed to subscribe to topic).

Situation 2:

  • Installed Multitech Lora Network Server
  • Installed ChirpStack Packet Forwarder
  • Installed ChirpStack Gateway Bridge

In this situation, the gateway bridge connects and subscribes to a MQTT topic on GCP. However, I have no idea how to connect my LoRa devices to the Lora Network Server as when I start the server it keeps reporting that packet forwarder is not found.
I only installed the Lora Network Server as I could not figure out any other way to configure my Lora network (Network name/passphrase).
The step reached is the “Your gateway is now communicating successfully with the Cloud IoT Core MQTT bridge!” on the Google Cloud tutorial, I did not proceed past this step.

Situation 2 would be preferred to solve the solution as I find the Chirpstack documentation easier to follow, but I feel like there is a step missing on https://www.chirpstack.io/gateway-bridge/gateway/multitech/ and that is how to configure the Lora Network Server to connect.

I have tried quite a few things to get this to work. The main 3 files that I am modifying are:

  • /var/config/lora/lora-network-server.conf
  • /var/config/lora-packet-forwarder-ap2/global_conf.json
  • /var/config/chirpstack-gateway-bridge/chirpstack-gateway-bridge.toml

Or am I missing the point entirely and do I need to run a Lora server on GCP for me to able to connect my devices? (As in, can’t just run a local Lora Network Server with a name/passphrase?)
So I need to set up a postgre databse etc to get all this working?

Thank you

2

Hi,
Did you succeed to connect your device since then ? I’ve got the same problem …

3

Hi Mushu

Situation 1.
If you want to run the Multitech Lora Network Server and Packet Forwarder, you do not need to install anything from Chirpstack.

In this scenario you need to write a MQTT Python/Java/NodeRed script that will read the MQTT data from the Network Server and forward it to your cloud provider. I recommend Python.

You can try run this script from a PC on the LAN first, by modifying the Mosquitto configuration. There is a single line in the Mosquitto configuration that when you comment it out the MQTT packets get forwarded to your network. Just search for “bind_address” in the mosquitto conf file.

Multitech support provided us with a Python script to do this with Azure on the Conduit, but not Google Cloud.
We have our own script for Google Cloud going on a PC and are now working to try get all the Python libraries on the Multitech Conduit so we don’t need to use a PC.

We have just received an email from Multitech with the links of where to download the crypto python libraries we need to connect to Google cloud and will be trialing it in the next few days. Google cloud uses JWT which seems to be a bit more demanding.

Simplified:
Radio <-> Packet Forwarder <-> Network Server <-> MQTT <-> Your App here <-> Cloud

I can try to supply more information about this if this is what you are trying to achieve. The above is a very quick summary.

For Situation 2.
We got this working but did not like running the Network Server in the cloud.
It works as follows (CS = Chirpstack)

Simplified:
Radio <-> CS Packet Forwarder <-> CS Gateway Bridge <-> Cloud <-> LoRa network server etc…

We had a few issues due to frequency (we need AS923), so we did the entire tutorial with US915 first and then made the necessary changes when it was running. Not ideal, but easier to follow the tutorials.

4

To install Python on the Conduit (mLinux):

opkg install python-pip
opkg install python-setuptools
pip install paho-mqtt

According to Multitech support: DO NOT RUN THE UPGRADE ON PIP!!

For Python libraries you can run: “opkg list|grep python*
Or browse the following URL: http://www.multitech.net/mlinux/feeds/5.1.8/arm926ejste/

(The above URL assumes mLinux 5.1.8)