How to send a downlink to your mote via ttn network using ttn.js

Application Development
1

Does any one know how to publish a message to the TTN using the code below:

var ttn = require(‘ttn’);
var appEUI = ‘xxxxxxxxxx’;
var accessKey = ‘********************************************’;
var client = new ttn.Client(‘staging.thethingsnetwork.org’, appEUI, accessKey);

client.on(‘uplink’, function (msg) {
console.log(‘Received message’, msg);
});

client.on(‘activation’, function (msg) {
console.log(‘Device activated:’, msg.devEUI);
});

2

Looks like the ttn.js SDK doesn’t support that at the moment.

3

Any info about ETA of downlink?

4

@MikeAski: ok, now I see why you said you didn’t find a definitive answer to whether downlink is supported or not. So, to clarify a bit more: downlink is supported as of today, support is limited to Class A devices.

This forum topic refers to downlink support in the node.js SDK, not in the network itself. And between the last answer and now, downlink support has been added also to the SDK: https://github.com/TheThingsNetwork/sdk/commit/3786646c9921ee9af25e1843fb78f39f5ca64811

:smile:

5

Ok, thanks a lot for this clarification :+1:

6

Downlink with node.js :

client.send(devID, "01",1)

devID = speaks for itself.
“01” = string with the data you want to send.
1 = port you are communicating with ( see your data in the console).

Compleet example:

var ttn = require("ttn")

var appID = "****"
var accessKey = "****"

ttn.data(appID, accessKey)
  .then(function (client) {
    client.on("uplink", function (devID, payload) {
      console.log("Received uplink from ", devID)
      console.log(payload)
      client.send(devID, "01",1)
    })
  })
  .catch(function (error) {
    console.error("Error", error)
    process.exit(1)
  })
7

Just for future readers, as per the documentation:

  • payload (PayloadArray | PayloadRaw | String | PayloadFields) The raw payload as a Buffer, an Array of numbers, a hex string or an object of payload fields.