Tag: portfolio

Generic SDR realtime IQ converter

With CubicSDR, HAMLIB, and Max

CubicSDR uses the SoapySDR library as generic tool for extracting realtime IQ data streams from common SDR devices. It also provides TCP external frequency control using HAMLIB.

http://cubicsdr.com/

Although its not the main purpose of CubicSDR, the IQ streaming capability will connect SDR devices to Max, Pd, and other DSP platforms, to build experimental radios. All without building external objects or hardware device drivers.  The convenience of using CubicSDR for this purpose far outweighs the overhead.

A prototype with Max and rtl_sdr

How to use CubicSDR as a front-end for SDR experiments in Max.

The signal path for this test is:

  1. antenna
  2. NooElec HAM IT UP upconverter
  3. rtl-sdr dongle
  4. CubicSDR
  5. Soundflower (or a “loop-backed” external audio device)
  6. Max

Running in the other direction, the frequency control path is:

  1. netcat running in Mac OS X terminal (or a Max patch that sends TCP)
  2. rigctld (hamlib TCP server)
  3. CubicSDR
  4. rtl-sdr dongle

There’s a lot of stuff going on here, so the choice to use hardware audio routing instead of Soundflower and netcat instead of TCP in Max, is an effort toward simplicity.

CubicSDR settings:

  • Plug in the rtl-sdr before launching CubicSDR, so it will be discovered on the setup screen
  • On the main display, click just to the right of the mode buttons to bring up a drop down menu of audio devices
  • select I/Q mode
  • select the audio device, or Soundflower, that you will use to route audio to Max
  • If using an upconverter, set the ‘frequency offset’ in the settings menu (e.g. -125000000)
  • click on any of the frequency digits, press space, and enter in the same frequency as the Center Frequency (e.g., 7000000)
  • click the ‘V’ to the left of the frequency digits, to select ‘delta lock mode’. This causes the frequency and center frequency to sync.
  • Be careful not to click anywhere in the waterfall window – or this will mess up the sync
  • Under Rig Control menu:
    • Select “Hamlib NET rigctl” as the model
    • Enter localhost:4532 as the control port
    • Select 57600 as the serial rate
    • Make sure that “follow rig” and “floating center” are checked
    • ‘Check’ ‘enable rig’. If it doesn’t stay checked, then there is a problem with the connection.
  • Under the Audio sample rate menu, select the correct sample rate for your audio device (e.g. 96k)

TCP and rigctld settings

  • Open a terminal window
  • type: rigctld -m 1 4532 &
  • This starts the server running in the background using the HAMLIB test dummy rig
  • to set frequency to 7.010 MHz, type:

    echo “\set_freq 7010000” | nc -w 1 localhost 4532

  • This should change the center frequency and frequency in CubicSDR

Max settings

For this test, you can use any of the MaxSDR tutorials available at https://github.com/tkzic/maxradio but I chose to use the main program, currently maxsdr7a.maxpat. The key is to choose the default audio input device and set it to be the same as what is coming out of CubicSDR.  I used a stereo patch cord to connect the line output of my Apollo Twin interface to the input jacks – but you can also use Soundflower.

  • Set the audio input device to match CubicSDR, as described above. Also match the sample rate (e.g., 96k)
  • Set the audio output device to your internal soundcard/speakers
  • You may need to toggle the flip IQ button
  • Start audio and recall preset 1 or some normal settings for SSB
  • It should be receiving I/Q data now from Cubic SDR

Links:

Installing Hamlib: http://reactivemusic.net/?p=19402

Installing CubicSDR: https://github.com/cjcliffe/CubicSDR/releases

Supported SDR devices: http://reactivemusic.net/?p=19746

Notes:

I had some success using the Max TCP external described at the Installing Hamlib link above, but temporarily abandoned it due to some latency and dropouts.

Local version of this patch is: tcpClient-small2.maxpat

Next steps:

  • hardware (i.e., MIDI controller) control of frequency – and refinement of Max TCP patch. Can likely re-use the patch from the remote radio project.
  • Convert to PD : TCP/IP code is builtin
  • Consider forking CubicSDR and adding direct MIDI/OSC control of UI.

Black on white with Max 7

Making Max 7 look like 6.

What’s this about?

The UI in Max 7 reverses foreground and background from previous versions of Max (and Pd).  Additionally,  a secondary toolbar menu frames the patcher and all sub-patchers. For example, here is a simple Max 6 patch and its Max 7 equivalent.

Max 6:

Max 7:

Regardless of which look you find more appealing, the new UI is problematic in several ways.

  • Light text on dark background can be difficult (blurry)  for people with vision impairment – given the same font size and screen brightness.
  • Patches created in previous versions of Max lose their original design.
  • Larger objects and toolbar frames consume more screen space.
  • If you like to sketch ideas with pencil – an empty white patcher screen is like paper.

Max 7 doesn’t include a black-on-white style, but you can make your own. And lose the toolbar. Here is a new and improved version of the patch:

Making a new style

The process is arcane. But it took less than a half hour to get results. Then I wasted time endlessly tweaking.

The secret recipe came from a 2014 Cycling 74 forum post by Phiol, with assistance from Ben Bracken. Everything you need to know is explained in Phiol’s first 2 posts in the thread. https://cycling74.com/forums/topic/custom-color-scheme-layout-setup-walkthrough/#.V6oHMZMrIcg

I encourage you to read both posts and follow the steps precisely. There are no shortcuts. I will paraphrase Phiol’s method here:

  1. In a default patcher, make a bunch of objects and then in the Format Palette (object inspector) change them to whatever colors you want
  2. Select all the objects in the patcher
  3. In the Format palette, make a new style – this style will be for multiple objects
  4. Select the patcher to activate it in the Format palette
  5. In the Style menu (located in the patcher inspector window), select the style you just made, applying it to the patcher level
  6. Delete all of the objects in the patcher
  7. Save a new template (in dropdown file menu “create template”) and make it your default.

And then the bad news:

Step 1. is important.
  • You must start from a blank “Default Patcher Template” and choose “Default Max7”
  • You cannot copy/paste objects that you had already done your custom colors. You will have to start from scratch. one by one.
  • In the inspector window, make sure the “Appearance style” has nothing selected in it’s umenu

Then do all the steps mentioned in the previous thread.

The Glitch/bug:

-Gradients objects do not work.
For example, [message and umenu] would not keep my custom colors.

Workaround: Once you have started a new patch, reselect your “custom_style” in patch inspector window or the ‘format’ sub menu. That is, click the style that should already be selected/checked – and now it should work.

So yes, for now, as we start a new patch we will we have to make it a habit to always select our “custom_style” in patcher inspector window or the format sub-menu.

patcher inspector window

format submenu

(click the paintbucket icon on the top toolbar)

 

Copy style to library

Also, when you open older Max6 patches and/or the help patch and want to apply your new custom style template, make sure that in the “Format” dropdown menu you have selected the “copy style to library”.

Loading Max 6 patches

Once you’ve done this, you will be able to apply you’re custom style to older/help patchers and resave them with your custom look. To do so, you open Inpector’s Appearance again, and select your “custom_style” that will be in the Library style.

Walking through the process of step one

If you are totally confused at this point, so was I.

Starting with step one above,  make a patch with common objects, that looks something like this:

Select each object individually, then with inspector, change the background color to white, or a lighter shade, and the text color to black.

You may need to experiment. Try with a small number of objects at first – because you will probably need to do the whole process several times. As noted above, you have start from the begining  each time by hand. You can’t modify a style after you save it.

Then, you should be able to follow the rest of the steps from Phiol’s post.

The objects used for this style are:

  • umenu*
  • button
  • dial
  • toggle
  • generic object
  • textedit
  • slider
  • message*

*these objects use gradients

Making a white patcher background

  • open a blank patcher
  • ctrl click on the background and select “Inspector Window”.
  • Change the unlocked and locked background colors to white.
  • Then, from the File menu, select ‘create template’ and give it the same name as the template you selected in step 7 above (and make sure to check ‘default for new patchers’)

Getting rid of the tool bar frame

The procedure is basically the same as setting the white background.

  • In a blankpatcher, open the inspector window and uncheck ‘show toolbar on open’.
  •  Then, from the File menu, select ‘create template’ and give it the same name as the template you selected in step 7 above (and make sure to check ‘default for new patchers’)

Note: you can toggle the toolbar anytime with <cmd>8

 If subpatchers  still have the default look

If you create a subpatch and it reverts back to the default style then…

  • In a blank patcher, open the inspector window and set the subpatcher template to your new tempate created in step 7 above.
  •  Then, from the File menu, select ‘create template’ and give it the same name as the template you selected in step 7 above (and make sure to check ‘default for new patchers’)

More about styles and templates in Max 7

Check out the Cycling 74 vignettes about styles and templates to get a better understanding of what’s going on here:

https://docs.cycling74.com/max7/vignettes/styles

https://docs.cycling74.com/max7/vignettes/templates

SDR Panadpter, logger, and skimmer

With a TenTec Eagle transceiver, Managed by N4PY software.

n4py-diagram

http://www.n4py.com/

N4PY acts as router, distributing CAT commands to other applications.

The applications are connected using virtual serial port bridge pairs. For each of the applications, N4PY emulates a K3 transceiver on one side of the bridge.

  • Panadapter: NAP3
  • Logger: N1MM
  • CW Skimmer

The CW keyer is a K1EL Winkeyer USB controlled solely by the N1MM logger.

The routing of IQ signals from LP-PAN2 SDR is done through a MOTU 828 mk3 interface, simply to be able to split the signal so that both NAP3 and CW Skimmer can use it.

CW Skimmer gets the IQ signal directly from the MOTU. NAP3 doesn’t not recognize multiple ports on soundcards. So one end of the split from the MOTU is sent through another audio interface (Focusrite 2I2). NAP3 uses the 2I2 as an input device.

LP-PAN frequency adjustments

Notes on configuration for correct zero-beating.

When setting the Eagle BW or PBT, the IF will shift in frequency, so the numbers below assume a centered PBT and a BW of 700.

The sidetone pitch is 523 Hz.

Settings may also depend on which roofing filters are installed in the Eagle.

NAP3 settings

Set the global offset to -8200. Leave everything else at 0.

CW Skimmer settings
  • CW pitch: 523
  • Audio IF: -7520
  • Sample rate: 96 kHz
  • Hardware: SoftRock-IF

This post is about ham radio.

SQLite database for remote radio in Max

under construction…

Max/MSP features a full implementation of SQLite using the js (javascript) object. Here we describe a database to track radio frequencies. Frequencies are stored by time, type, and mode. The frequencies can be retrieved in various ways, like with a scanner radio.

Tables can be created and maintained outside of Max using the command line (sqlite3) or database apps like SQLiteStudio.

Max patches:

(not yet available on github:

  • freqdb4.maxpat (database UI)
  • swBase3.js (SQLite code)
  • lp_radio2.maxpate (Launchpad)

DB structure:

The database is called newtestDB1

tables:

You can see the table schema in the screenshots. The tables were created using command line sqlite3 and SQLiteStudio.

freq table:

One record for each stored frequency. This table retains its state from each previous use, but new records can be added using the Max patch, or the Launchpad.

Screen Shot 2016-04-05 at 11.00.31 PM

xtime: Timestamp in UTC.

frequency: Hz.
mode:

  • usb: 0
  • lsb 1
  • cw 2
  • am 3
  • fm 4

filter: bandpass filter setting in Hz. (default is 6000)

typecodes:

0 : unknown
1 : AM/SW broadcast
2 : clock
3 : digital mode
4 : local broadcast
5 : mostly noise

zone: cq zone number

rating: 0-5 (0 = unrated)

confidence: 0-5 (0 = unknown)

tags: (general text notes)

preset table:

The preset table contains one record for each 8×8 launchpad button, for each of 3 screens.

  • screen 0: fixed presets (red) (static and persistent)
  • screen 1: time presets (green) (rebuilt with each time query)
  • screen 2: user presets (yellow) (persistent but can be modified using the Launchpad)

Data from each of theses screens is also displayed in jit.cellblock objects in the Max patch. All of the fields correspond to the fields in the freq table – except for screen, row, and col which are locators for the launchpad.

Screen Shot 2016-04-05 at 11.11.08 PM

Using the database

Launchpad presets

There are three screens of presets color coded using the Launchpad mixer button (upper right). Press it to cycle through the 3 screens.

0 fixed presets (red)

The fixed presets are static. But can be changed using SQLiteStudio. They contain commonly used radio frequencies, like the SW, Ham, and CB bands. And clock stations.

To select a preset, press its button on the Launchpad.

Currently assigned presets:

Screen Shot 2016-04-05 at 11.39.12 PM

1 Time Presets (green)

Time presets are frequencies with Timestamps that match a selected range. For example, every frequency within one hour of the current time. These can be selected with a query in the Max patch, or using default values from the Launchpad. The query will randomly match up to 64 records. If the query returns less than 64 records, you will get all matching records, but in random order.

From the Max patch:

Match hours plus/minus current time (0-12).

Type the number of hours in the number box and press the button under the delay object. This reloads the presets.

Screen Shot 2016-04-05 at 11.36.35 PM

You can view the results in the jit.cellblock:

Screen Shot 2016-04-05 at 11.39.07 PM

 

Match a specific time range:

Enter the start/end times and press the button.

Screen Shot 2016-04-05 at 11.40.51 PM

 

Selecting from launchpad

trk button: re-runs query using last set number of hours plus/minus current time. Default is one.

solo button: select one random preset using current hour range, and play it?

 

User Presets (yellow)

The user presets work like the pushbuttons on a car radio. Press to select. Hold to save the currently tuned radio frequency.

The learn button (upper left) gives feedback. If you press a pad for which no frequency has been assigned, the learn button will flash red. When you save a new preset, the learn button flashes green to indicated that the saving is done. If you press a pad for a preset that has already been saved, there will be no flash, but the radio frequency will change.

Adding new frequency records

You can add records using the Max patch or the Launchpad, or from SQLiteStudio.

Adding records from Max:

Tunning the radio fills in all of the fields except for typecode. Tune the radio. Then press one of the typecode buttons. Then press the big green button. You have added a new record.

Screen Shot 2016-04-05 at 11.55.57 PM

 

Adding records with Launchpad:

Press the Arm button (lower right) to add a record for the currently tuned frequency, using an ‘unknown typecode’

Adding records from SQLiteStudio

Just do it.

Remote radio – client

How to set up the client side of the remote radio system.

(under construction) patches have not been uploaded to github

This client works with the sever described in the previous post. We are running a MacBook Pro OSx 10.11.4. with the following:

  • logmein hamachi VPN
  • Soundjack VOIP
  • Max/MSP
  • Novation launchpad
  • DJ-Tech CDJ-101 controller

VPN

Install and set up LogMein Hamachi. It is free, for a limited number of computers.  Set up a Hamachi server on both the server and client. It should look something like this:

 

VOIP

We are using Soundjack VOIP. It is also free. Use the following parameters on the client side.

  • mic: soundflower 2ch (or something that is not currently producing input!)
  • headphone: default output (or whatever you want to listen on)

Screen Shot 2016-04-05 at 12.23.54 AM

You can ignore the rest of the settings, since we are not sending audio. Most of the configuration is done on the server side.

Max

We are using several patches, depending on which hardware controllers you are using. Make sure that the hardware controllers are connected before opening Max.

patches:
  • eagle-ui5.maxpat – User interface and main entry point for client communication and CDJ-101 abstrations

Screen Shot 2016-04-05 at 12.28.56 AM

  • freqdb4.maxpat – database handler

Screen Shot 2016-04-05 at 12.29.17 AM

  • lp_radio2.maxpat – launchpad driver

Screen Shot 2016-04-05 at 12.28.41 AM

After the max patches are loaded, you should be able to control the radio using the UI and the CDJ-101 controller. The red Mixer button in the upper right corner of the Launchpad should be lit.

Instructions:

to be continued…

Remote radio – server

How to run the server side (base station) of the remote shortwave radio system.

(Under construction) The patches have not been uploaded to github yet.

Assuming that the radio and antenna system are operating. We are using an internet connected MacBook Pro running OSx 10.9.5, with a MOTU 828 MK3 audio interface.

VPN

Install and set up LogMein Hamachi. It is free, for a limited number of computers.  Set up a Hamachi server on both the server and client. It should look something like this:

 

VOIP

We are using Soundjack VOIP. It is also free. Use the following parameters on the server side.

Local Settings:
  • mic: audio interface channel that is connected to radio audio output
  • headphone: doesn’t matter
  • volume: 0
  • audio block samples: 512
  • channels: 2
  • network packet samples 512
  • quality: high
  • userlist: manual

Screen Shot 2016-04-05 at 12.38.03 AM

User list:

UDP/IP: enter hamachi IP of client.

When Soundjack is set up on the client. Press the green start button on the right side of the user list window on the server.

If all goes well, you should hear the radio on the client. Note: The input meter under local settings should be registering audio from your radio. If not, there is a problem with the audio interface.

Max Server

The Max/MSP server exchanges CAT commands via the server serial port to the radio. The command data is exchanged with a Max patch on the client using OSC (over UDP).

Screen Shot 2016-04-05 at 12.46.02 AM

patch:

eagle-cat8.maxpat

instructions:
  • select the radio serial port from the menu (for example: usbmodem 14531)
  • initialize port settings
  • set toggle to poll the serial port

At this point you should be able to try the example commands, for instance to get the version or set frequency. If the commands are not working, it indicates a problem with the serial connection to the radio.

Next, check the IP address of the udpsend object. It should be the hamachi IP of the client.

 

Remote controlled shortwave radio system

Under construction…

The first in a series describing a system for internet remote control of a shortwave radio station. Its not something new. There are commercial products that provide remote operation of amateur radio transceivers. The purpose of this project is to make it possible to use shortwave radio sounds in musical performance, without the need of an antenna system.

Features:

  • Max/MSP for USB serial control of radio, OSC remote interface, user interface, Midi device handling, and an SQLITE database of preset frequencies.
  • Low latency, good quality audio using Soundjack by Alex Carot.
  • Hardware control of radio using Midi controllers (CDJ-101 and Launchpad)
  • Bi-directional OSC and VOIP using Logmein Hamachi VPN
  • Additional hardware control of AC power and antenna selection using Arduino and a WeMo switch.
  • TouchOSC Ipad audio mixer control using MOTU Cuemix
  • TeamViewer remote desktop software for logging into to base station compuer
  • Optional radio user interface control with Ipod TouchOSC, Griffin Powermate dial, and Korg Nano-kontrol.
  • Optional VOIP backup using Mumble.

System diagram

base station:

remote-radio-sys1

remote control:

remote-radio-sys2