Prerequisites

• Set up Conduit mLinux and mDot for use with LoRa. Refer to Getting Started with LoRa Conduit mLinux (LoRa Configuration) .

Receive Packets on the Conduit

• Use MQTT to show all received LoRa messages on the console:

  $ mosquitto_sub -t lora/+/up

  OR

• Use UDP and netcat to show all received LoRa messages on the console:

  $ nc --udp --listen --local-port 1784

  If UDP doesn’t work, confirm udp[“appPortUp”] is 1784 by looking at the config that’s printed in /var/log/lora-network-server.conf when the server starts.

Transmit Packets from the Conduit

Queue downstream packets on the Conduit by publishing the packets to the mosquitto or UDP channel for a specific mDot like this:

$ mosquitto_pub -t lora/00:80:00:00:00:00:6a:1a/down -m '{ "data":"aGVsbG8gd29ybGQ=" }'

or

$ nc --udp localhost 1786 <ENTER>
lora/00:80:00:00:00:00:6a:1a/down {"data":"aGVsbG8gd29ybGQ="} <ENTER>

• The packet must be in JSON format and the data must be Base64 encoded
• To transmit one packet back to the mDot, the Conduit must receive one packet from the mDot.

Downstream Packet Options

• Require acknowledgement from mDot

  { "data":"aGVsbG8gd29ybGQ=", "ack": true }

• Send data on a specific port to mDot, if not specified port 1 will be used. (this is FPort in the LoRaWAN protocol)

  { "data":"aGVsbG8gd29ybGQ=", "port": 6 }

• Send mac commands on to mDot in node.js

  // Send a new channel to mDot
  // NewChannelReq
  
  // Channel Index    - 1 byte
  // Frequency        - 3 bytes
  // Datarate Range   - 1 byte
  // 	Max :4      - DR 0-7
  // 	Min :4      - DR 0-7
  
  // Frequency converted to HEX and reversed for network byte order
  // 869100000 / 100 --> 0x849D38 --> 0x389D84
  
  // Example: add channel 4 869100000 DR0 - DR5
  
  // ID | Index | Frequency | Range         Base64
  // 07    04      389D84      50      ---> BwQ4nYRQ
  
  var cmd = new Buffer([ 0x07, 0x09, 0xf8, 0x7d, 0x84, 0x77 ]).toString("base64");
  
  var packet = JSON.stringify({ "data": cmd, "port": 0 });
  
  var topic = "lora/" + eui + "/down"
  
  client.publish(topic, packet);

• Generate mac commands with nodejs on command line

  test ADR command 0341ff0101
  CMD   DR PWR    MASK  CTRL
  03    4  1      ff01  01
  

  $ node
  > new Buffer("0341ff0101", "hex").toString("base64")
  'A0H/AQE='
  <CTRL>D
  $ nc --udp localhost 1786 <ENTER>
  lora/00:80:00:00:00:00:6a:1a/down {"port": 0, "data":"A0H/AQE="} <ENTER>
  

Sample Node.js App

• Download a sample Node.js app that demonstrates how to receive and send LoRa packets.
• Copy the tarball to the Conduit: scp Downloads/lora-sample-app.tar.gz root@192.168.2.1
• ssh into the Conduit
• Unpack the tarball: tar -xzf lora-sample-app.tar.gz
• Run the app: node lora-sample-app.js (it’ll take a little time to start)
• To echo received packets back to the mDot, uncomment this line at the end of the file:

      // uncomment to send the same message back to the dot
      // send_to_node(eui, json.data)

Using the sample app on the mDot:

Troubleshooting

• Conduit mLinux: LoRa Use With Third-Party Devices
• Troubleshooting LoRa Communication