The Max remote receiver project described in an earlier post: https://reactivemusic.net/?p=20965 now includes support for OpenWebRx and KiwiSDR sites.
When using OpenWebRx, you need to select a “profile” that supports the receive frequency range, before you can operate within that frequency. Its an unusual system that uses an offset frequency within the selected profile, instead of a global “actual frequency” like the other platforms.
The KiwiSDR sites, in general, have very good quality reception and audio.
The next step in this project will be to consolidate a directory of sites that are useful for remote reception in the ham bands for various parts of the world.
This Max patch connects to a radio transceiver and reads the frequency data using hamlib. Hamlib provides a common API for amateur radio devices. https://hamlib.github.io/. The hamllib server runs in the background using TCP/IP. This patch uses Jeremy Bernstein’s shell object. https://github.com/jeremybernstein/shell and the Sadam Library of externals, installed with the Max package manager.
Files
hamlibtcptest1.maxpat : select radio, starts rigcltd dameon, poll frequency via tcp/ip
launch-rigctld.sh : shell script to run rigctld
Libraries
Max: Jeremy Bernstein’s shell external, and the sadam library from Max package manager.
hamlib can be installed using homebrew
Notes
There is some latency when using the Elecraft K4. Need to look into the internal CAT settings.
Also, look into communication latency of TCP/IP and associated libraries.
I’m exploring a version of this that uses node.js instead of the shell external and tcp/ip library in Max. Initial problem is that the rigctld daemon stays active after Max is closed and needs to get killed manually.
Mapping geocoded contest log data using node.js and openlayers.
The goal was to make something that looks like the Reverse Beacon Network map, only for contest log files. I use RBN for testing antennas now. That map display gives you a pretty good idea of your actual antenna pattern.
Code is written in node.js (javascript) and html.
Part 1: Read a Cabrillo log file containing QSO: records. Look up each callsign, get latitude and longitude, and rewrite the file as json data, tagged with geo coordinates. I originally tried getting the data from hamQTH but it was not current, so ended up using the qrz.com xml callsign lookup. For callsigns “not found” I used the qrz.com dxcc prefix lookup to get general coordinates for the country. There are still a few bad/missing data issues to resolve. Like European stations with coordinates at the South Pole.
Part 2: Tried various mapping frameworks – like leaflet, arcgis, and openlayers. Wanted to use a great-circle projection (azimuthal equidistant) like the big ARRL world map. And may still figure this out. But working with map projections and coordinate transforms is way worse than doing a Smith Chart. I ended up hacking a flight tracking example from openlayers.org and basically replacing airplanes with QSO’s. That is why the lines are animated from source to destination. Also added a layer for day/night, and QSO/time status display.
It probably makes sense to get rid of the flight animation and just display the entire path in sync with the QSO data – with color code for each band (K1KP) – and speed control on the time lapse, etc., So you can get a better sense of rate and propagation.
It would be cool to have a website where you could upload a log file and generate maps.
Note: this project is not yet available
Files
local files:
generating data:
internetsensors/cabrillomap
put the cabrillo data in testdata.cbr (use QSO: records only for now) should be sorted chronologically.
run: node index.js
the output file will be: geocab.json (which is used as input to the mapping program)
mapping
internetsensors/oltest
main.js = node source with ol mapping and data processing
index.html = web page for map
geocab.json = geocoded cabrillo json test data
to run, type: npm start
Then open: http://localhost:5173/ in a browser
Additional work / current issues
Some of the qrz.com callsign data has bad geo coordinates. In particular some of the records show a latitude of -89 and longitute -179 – need to check for these numbers and replace with dxcc coordinates.
There should be an argument on the node program to pass in the datafile. Also the program should clean up any non QSO: records, like the file header info and any X-QSO recs.
Also need to clean up the async/await stuff – currently there are several methods for handling state transitions.
mapping ideas:
As mentioned above, its probably a good idea to make a version of the code without the flight animation, and have various controls to stop/start the data playback to look at individual qso’s do speed control, etc.,
azimuthal equidistant projection: there are some links to examples in leaflet, and arcgis to handle complex projections. In documents, look at: “map links for projection stuff.txt”
leaflet test version:
in the internetsensors/cabrillomap folder there’s a test file: cbworld1.html that works using websockets when you run the index.js file to generate test data. It uses a leaflet map, but the lines don’t adapt to great circle polar paths.
arcgis
I believe the arcgis examples are in internetsensors/projected geometries
And: internetsensors/pe-gs-projection
The former is a a very nice world projection with some point markers. The latter is an example that shows how to switch out various projections in realtime.
Attempts to use the X API (formerly Twitter) for projects with Max/MSP have been disappointing at best. Most of the API is behind a paywall now. The cost is $5000 per month. to implement streaming API used in projects like this: https://reactivemusic.net/?p=5786
The free tier only allows basic tweeting and user lookup. Search is not available.
I was able to find only one node example that actually worked in the free tier. By “Coding with Ado”. The code requests a token from X, and then you enter a timestamped pin number to continue. Making it worthless for programs and bots. https://youtu.be/G5ZW5j5cwHk?si=vbAtGa0bQ3T_tga9
A local copy of the source code for this is in tkzic/nodetweet3/index.js
There service sits in the middle to handle X API calls. You are charged by the number of calls. It doesn’t offer streaming either, but you can simulate it by calling a search every few seconds.
Other social media options
There are API’s for other social sites like facebook, instagram, tiktok, etc.,
In the previous version, all of the markers for each train line were deleted and redrawn in a group at the polling interval. In this version the train markers move to their new location when the data is polled.
The project uses the MBTA JSON API, to query vehicle data for each train line. the geo coordinates of the trains are sent via websockets to the client map page.
This project is a work in progress and not available yet.
Files:
node server: internetsensors/mbtanode2/index.html
html map client: internetsensors/mbtanode2/mbtatrain2.html
Instructions
// to run, type node index.js at a command line.
// then open a web browser to: http://127.0.0.1:8124/
// type 'go' into the text box below the map, and press 'send' button
// in a few seconds the train markers will magically appear
I needed a text to morse code generator in Max for the Twitter streaming map project. There was an ancient one that used [mxj] but its kind of a pain to use that object. I thought it can’t be that difficult to write one? I didn’t really have any idea where to start. Something about the blank Max patch causes brain activity? I went through about 5 different approaches. Eventually came up with this pattern thing, from thinking about the lighted buttons on the tr-808 drum machine.
For example, the letter A is . _ (dot dash)
morse code has rules for spacing:
dot = 1
space between tones = 1
dash = 3
space between letters = 3
space between words = 7
If you think of a drum machine pattern, the pattern for letter A would be: 1 0 1 1 1 0 0 0 (with the 3 trailing 0’s for letter spacing)
I made a [coll] with all the letter patterns indexed by ascii codes.
Then just concatenate letter patterns, for a given block of text, together into one big list and run it through [zl.nth] clocked by a [metro] and [counter]. the ones and zero’s turn an oscillator on and off.
local file: tkzic/internetsensors/twitter-stream2/morse5.maxpat
Milford Graves was one of my all time favorite musicians. His approach to percussion, and music generally, was unique in a way that defies explanation.
I sampled a bunch of clips of his drumming into Ableton live and then experimented with the Buffer Shuffler 2.0 device to see if I could randomize small slices, ie., several seconds each, of longer samples – without losing the “texture” of the original recordings.
Here is an example of what it sounds like:
This video shows a clip from David Murray’s “Real Deal” running through Buffer Shuffler using slices only about 2-3 seconds in length. The slicing rate is just arbitrary, since there is no warping or specific clock pulse.
Local files: tkzic/aardvark/milfordgraves1 project/milfordgraves1a.als
But it won’t run from that server. It only runs locally.
Instructions
Download the index.html file from the link above. start a local web server, eg., “npx http-server” and enter the server address into a Chrome browser.
When you press connect, the browser will prompt you to select a serial port for the radio. On my computer the K4 serial ports appear something like: cu2.usbserial-21100. There are 2 ports. Select either one.
Then press read. If you spin the dial on the K4, and it is autoinfo mode, you should see CAT commands in the read window.
enter a CAT command in the write window and press the write button. It is preloaded with “fa7;” which sets frequency to 7 MHz.
I was unable to find any apps to create virtual serial ports for later versions of Mac OSx eg., Catalina.
There is a partial solution using the linux socat utility. It will create functioning vsp’s but the ports will not be detected by most apps, like Max/MSP. I tried setting a symlink to files in /dev using tty. and cu. prefixes. eg., /dev/tty.x1. But apps that look for serial ports still couldn’t detect the vsp’s.
Instructions
download and install socat using macports or brew. eg., “sudo port install socat”
Disable SIP (system integrity protection). In Catalina, reboot holding cmd+r. Then type: “csrutil disable” into a terminal window. Reboot – Note: you probably don’t need to do this if you aren’t setting up a link in /dev – which so far doesn’t work anyway
