Background

Continuing with using Node-RED to handle messaging for radio related things I’ve created some flows for using with the interactive chat service at www.on4kst.com.

This web and Telnet based messaging service is invaluable for VHF+ users for contests, scheduling and band related chat.

The web interface is great for using while at home but when out portable using a mobile device it is a bit fiddly. Additionally, during contest/activity days, the messages can be flying by so quickly a page of text can scroll past in a moment and it’s easy to miss out messages even when directed at you with the /cq prefix. After my last outing portable I returned home to see I had been called but hadn’t noticed.

Prompted by some discussion of this on the ukmicrowaves mailing list and a mention of IRC which I use a lot I thought I should have a go at sorting something out for myself and others if interested.

There are applications that can be used to access KST chat such as the contest logging software tucnak for raw access to the telnet interface and the Windows application kst2me which runs wellin Linux with Wine. Kst2me is great and would be the likely solution for most people with a computer to hand but it’s doesn’t solve my mobile device and alerting requirements.

Using Node-RED & IRC

By pulling the ‘kst chat in to Node-RED my intention was to filter messages to channels on an IRC service based on their content:

• A channel for all chat, effectively a mirror of whatever chat it’s connected to.
• A channel for nearby DXCC entries. As I’ll be using this for microwave outings I have some filtering if required during busy periods.
• A channel for direct messages sent to me with the /cq prefix so I have everything directed to me in one area.

I also want to be able to send messages to KST from my own IRC client via the channels above. A two way set-up is intended for a single user and care needs to be taken to ensure that messages sent to KST are coming from the legitimate logged in user.

I’ve used IRC here because I am comfortable with it and have clients connected to IRC servers 24/7 and can connect to these clients from any device to pick up where I left previously. This means I can leave the Node-RED flow running at home on a contest day and connect to the IRC server as I need and have a full view of everything that has happened in each of the channels. This also means I don’t have to worry about disconnections or leaving it running all the time running batteries down.

Node-RED is however  extremely flexible and allows the messages to be sent to pretty much anything such as an MQTT broker, SMS messages, DMR SMS messages, Web APIs, TCP/UDP servers etc so the use of IRC here should just be taken as an example use.

I have also set the flow up to have CQ messages directed to me on KST to send me a direct message on Twitter to gain my attention on my mobile device when not viewing the IRC channel. I could have used SMS here but the Twitter application with alerts works as well and doesn’t require using a paid for SMS service.

Interfacing With KST Chat – Login

There are two interfaces to the KST chat, the web interface and the Telnet interface, there’s no API that I’m aware of. In this instance I’ve used the Telnet interface to interact with the service as it’s the least complicated for scraping purposes.

In order to log in via Telnet we need our username, password and the band chat we wish to connect to, once these have been provided we are placed in to the selected band chat room. The Telnet outout is shown below connecting to the quiet Warch chat number 11 for test purposes.

Free text at this point will appear in the chat channel and commands need to be prefixed with a forward slash, for instance /quit.

We can log in to the Telnet interface easily with Node-RED using built in nodes and very little customization.

The flow above will initiate the connection to the ON4KST Telnet interface and log in. The nodes do the following:

1. The first node is set to execute on start-up and contains three values, username, password and the chat number.
2. The function node takes the user, pass and chat, splits them and sends the username to output 1, the password to output 2 and the chat room number to output 3.
3. These three outputs are then connected to a TCP Request node, this node takes a hostname and port number, http://www.on4kst.info:23000 in this instance. This node allows both input to and output from the TCP connection.

We also have two delay nodes, as the user, password and chat are entered separately and prompted one after another, we insert a delay after the username and password to allow the next prompt to be displayed. If they are all sent at the same time the ‘kst Telnet interface will not accept them.

If we connect a debug node to the output of the TCP request node we will see the output from the telnet session.

Remember that anything sent to the interface will be immediately sent to the channel so take care not to send your password to an already connected interface. This has caught me out already!

Interfacing With KST Chat – Output

The output from the TCP request node is fed straight in to a function node with four outputs. The function node filters and alters data and directs it to the correct outputs. The four outputs link the function node to three IRC channels and one Twitter output.

The Process Output function node does a number of things. It firstly converts the utf8 input from the TCP node in to a string and strips out newline characters. This allows us to work with it easily.

It then splits the incoming messages up if they are identified as normal messages. The message format is as follows with TOCALLSIGN being the optional CQ message and the NAME being of a variable length:

TIME FROMCALLSIGN FROMNAME > (TOCALLSIGN) MESSAGETEXT

Once we have each of the above split in to variables we start to make decisions as to what to do with the incoming messages based on regex matches.

We have three IRC channels set up for this test, one for all KST chat, one for local KST chat and one for CQ messages directed at us.

If a message matches our callsign, when someone send’s a /CQ message to us, the message is sent to all of the four function outputs resulting in it appearing in all IRC channels and a message to our user on Twitter.

If a message matches a list of prefix’s local to me (2/M/G/EI) they are filtered to the local area IRC channel and also to the all KST IRC channel. This means I have filtered IRC channel containing British Isles chat, which for me in GI matches what I’m able to work, if I was in a position to work other countries it’s easy to add them to the list.

If a message is not a CQ directed to me or in the list of filtered prefixes it is placed in the all KST channel which can be monitored when traffic isn’t heavy.

Interfacing With KST Chat – Input

I have two Input types set up to send text to the KST Telnet interface.

The first was set up for testing purposes in the Node-RED interface and consists of buttons that will send commands when clicked. These buttons send the text to a function node than adds line breaks then forwards them to the TCP request node input.

The second takes input from the IRC channels I’ve configured Node-RED to connect to and carries out some validation of observed messages, processes them then forwards to the add line feed node for sending in to the TCP node.

The Process IRC node checks incoming messages and matches them with some rules. It requires that incoming messages originate from the channels the IRC node is connected to and from a username that matches my IRC clients username.

Once this incoming messages are validated, the node checks the content for commands before actin. For instance it will parse “CQ CALLSIGN Good evening”, prefix the CQ with a forward slash and send it to the telnet service  and it will appear as a valid “/CQ” command on the KSTchat.

Wrap Up

IRC is just a single communication method here, we could do this using any other messaging platform and integrate in to applications easily enough and make this more interesting easily enough. Node-RED allows easy control of messaging and simple coding in JavaScript to manipulate things.

I hope to try the described setup while portable with my microwave setup some time and imagine that the messaging ability to alert me to calls, and the use of a persistent IRC client to interact with people should allow me to keep track of KST chat in a manner I’m more comfortable with. (I did try this in a contest weekend up a hill and it worked just fine!)

My code is a horrible mess but I can forward it to anyone that would like to try something like this out. Here’s the whole thing:

Please have a look at some other Node-RED posts for more amateur radio uses if interested in the above:

• WSJT-X monitoring with py_wsjtx & Node-RED
• DMR SMS alerts using the SharkRF openSPOT and Node-RED
• Node-RED module for DMR SMS using an openSPOT