[Skimmertalk] CW Skimmer + RTTY Skimmer running simultaneously on Red Pitaya - Success!

Bob Wilson, N6TV n6tv at arrl.net
Sat Jul 1 01:40:09 EDT 2017


I finally succeeded in getting both CW and RTTY Skimmer to run
simultaneously on a single Red Pitaya SDR.  I hope someone else can confirm
that the procedure below works for them too.

Furthermore, I am able to view a live waterfall display *and* *listen *to
any band being monitored by the same SDR at the same time, using the HDSDR
software.  And finally, I was able to configure the RBN Aggregator to
launch both skimmers automatically and in the right sequence.

Screen shot, here:

http://www.kkn.net/~n6tv/N6TV_RedPitaya_CW_and_RTTY_Skimmer_and_HDSDR.PNG

I'm not sure if the procedure for doing this on the Red Pitaya has been
well-documented yet, so here's what to do.  It's similar to the process for
the QS1R, with some very important differences.

Red Pitaya Hardware and SDR Setup:

   1. The only Red Pitaya OS version that worked for me was the Customized
   SD Card Image linked below.  Do not waste time trying any other versions,
   such as the one that comes pre-installed on the Red Pitaya micro SD
   card, even though it's newer, or the one on the Red Pitaya web site.
   2. As discovered by K1TTT, use a single jumper to bypass the 1M ohm
   input impedance circuit.  Connect pins 2 and 5 (the two middle pins)
   together (pictures in W2NAF's doc linked below)
   3. I'm using a tiny 14:1 transformer supplied by Red Pitaya on the
   input.  I'm so glad I found the Red Pitaya rep. at Dayton.  I've asked
   him to let me know when this transformer will be available for anyone to
   order.
   4. I found a 10 dB preamp to be helpful on the high bands with my
   antenna.  Without it, I saw no change in noise floor when I disconnected
   the antenna on the high bands.  It was very nice to watch the noise floor
   in HDSDR.
   5. Configuration:  VE3DO Loop Antenna -> DX Engineering Receiver Guard
   -> 10 dB Pre-Amp -> 14:1 transformer -> Red Pitaya Input 2.
   6. I recommend a short BNC to SMA pigtail, rather than a BNC to SMA
   adapter, to reduce strain on the SMA connector.

Quick Summary, for Windows (software links follow):

   1. Copy *CWSL_Tee.dll* to the *SkimSrv* installation directory
   2. Copy *CWSL_Tee.dll* to the *RttySkimServ* installation directory
   3. Copy *HermesIntf.dll* to the *SkimSrv* installation directory
   4. *Do NOT* (repeat, do NOT) copy *HermesIntf.dll* to the *RttySkimServ*
   directory, otherwise everything stops when you try to start RTTY Skimmer
   Server after CW Skimmer Server
   5. Create a two-line file named *CWSL_Tee.cfg* containing only these two
   lines and nothing more:

   HermesIntf
   64

   6. Save *CWSL_Tee.cfg* in the *SkimSrv* directory
   7. Copy *CWSL_Tee.cfg* to the *RTTYSkimServ* directory
   8. Copy *CWSL_Tee.cfg *to the *RBN Aggregator* directory (a very
   important step)
   9. Copy *ExtIO_CWSL.dll* to the HDSDR installation directory, nothing
   more
   10. Just as for the QS1R, configure both *SkimSrv/SkimSrv.ini* and
   *RttySkimServ/RTTYSkimServ.ini* with identical values for the following
   lines:
   (mostly left blank below, for clarity):
   *DeviceName=01 CWSL_Tee on*
   FreqCalibration=1
   CenterFreqs48=
   CenterFreqs96=
   CenterFreqs192=
   SegmentSel48=
   SegmentSel96=
   SegmentSel192=
   Rate=1
   11. In *SkimSrv.ini* use:
   [Telnet]
   Port=7300
   In *RTTYSkimServ.ini* use:
   [Telnet]
   Port=7301
   (value not critical, but the two skimmers must *not* be using the same
   TELNET port)
   12. Manually *start CW Skimmer Server* *first*
   13. If necessary, select the SDR named "*01 CWSL_Tee on ..."* and verify
   normal operation. The device name may show strange characters (ignore)
   14. Manually *start RTTY Skimmer Server **second*
   15. Verify that both skimmers are still running and show no errors or
   warning messages.
   If you get errors, note them and immediately terminate both skimmer
   programs.
   Look at the CWSL_Tee and HermesIntf log files written to both
   directories to help identify the problem
   16. (optional) *Start HDSDR* and select *ExtIO_CWSL.dll* when prompted
   17. In HDSDR, use only the small pull-down menu in the ExtIO pop-up
   dialog to change bands.  You can listen to any band being monitored by
   the Skimmers.  Do not change the LO frequency, only the TUNE frequency
   (just click on the spectrum or waterfall)

Once the above is verified as operational, it's time to test the process
via the RBN Aggregator.

   1. Terminate HDSDR, RTTY Skimmer Server, and CW Skimmer Server, in that
   order
   2. Launch the RBN Aggregator and quickly click on the *ini Files* tab
   and select *Stop Rotation*
   3. Check the path and file names make sure you're launching *SkimSrv.exe*,
   and the same *SkimSrv.ini* file edited previously.  View the file with
   the *Edit* button to verify.
   4. On the *Secondary Skimmers* tab, last slot (#8), select IP address
   127.0.0.1 port 7301 or whatever you used in* RttySkimServ.ini*
   5. On the *RttySkimServ* tab, verify the full path to *RttySkimServ.exe*
   and *RttySkimServ.ini* - do not use any other file name here.
   6. Check the box *Force RTTY Skimmer Server to follow CW Skimmer Server*
   7. Go back to the *ini Files* tab and click the *NOW* button next to the
   proper *SkimSrv.ini* to launch both skimmers, in order.
   8. Verify that both Skimmer Servers start up normally with no errors,
   and show one telnet connection each.
   9. In the *Skimmer Traffic* tab of the Aggregator, you should see
   messages indicating telnet connections to both CW Skimmer and RTTY
   Skimmer
   10. In the *Status* tab, there should be no errors
   11. If you do have errors, look for HermesIntf and CWSL_Tee log files *in
   the Aggregator directory*.  The most common problem is not having the
   correct *CWSL_Tee.cfg* file in the Aggregator directory.

Here are useful links to all the required software files and extras, with
proper credit to all the developers and enthusiasts who made it possible
for simple folks like us to replace our failed QS1Rs with a Red Pitaya or
two:

   - Creating a 6-Band RBN Receiver Using a Red Pitaya
   <http://hamsci.org/cw-reverse-beacon-network-how-guide> by W2NAF (start
   here for sure)
   - Customized Red Pitaya SD Card Image File
   <https://www.dropbox.com/sh/5fy49wae6xwxa8a/AAAP62ge2aAqpTxTP1of5zLga/sdr/ecosystem-0.95-1-6deb253-sdr-receiver-hpsdr.zip?dl=1>
   by Pavel Demin
   - CWSL_Tee.zip <https://github.com/HrochL/CWSL/blob/master/bin/CWSL.zip> by
   Petr Parýzek
   - HermesIntf-16.6.27.zip
   <https://downloads.sourceforge.net/project/hermesintf/HermesIntf-16.6.27.zip>
    by Vasiliy Gokoyev, K3IT
   - Running-RTTYSkimServer-and-CW-SkimServer.pdf
   <http://hamsci.org/www.reversebeacon.net/downloads/aggregator/Running-RTTYSkimServer-and-CW-SkimServer.pdf>
by
   N4ZR
   - RBN Aggregator 4.4 <http://reversebeacon.net/pages/Aggregator+19> by
   W3OA
   - HDSDR 2.76 <http://www.hdsdr.de/> by DG0JBJ
   - CW Skimmer Server 1.5 <http://dxatlas.com/SkimServer/Files/SkimSrv.zip>
   by VE3NEA
   - RTTY Skimmer Server 1.2
   <http://dxatlas.com/RttySkimServ/Files/RttySkimServ.zip> by VE3NEA
   - OmniRig <http://dxatlas.com/OmniRig/Files/OmniRig.zip> by VE3NEA
   - Preparing a Red Pitaya SD Card
   <http://redpitaya.readthedocs.io/en/latest/doc/quickStart/SDcard/SDcard.html>
(not
   required unless you want to restore the SD image that came pre-installed,
   using the Win32 Disk Imager)


Random notes on the Red Pitaya:

   1. I couldn't find Pavel Demin's email address, but we all owe him a big
   THANK YOU for his Red Pitaya SDR Receiver.
   2. Follow the steps in W2NAF's excellent Red Pitaya RBN How-To Guide
   exactly; don't take any shortcuts:
   - The Red Pitaya Starter kit includes a new and improved v0.97 operating
      system, which boots fine and has handy features, but I have not been able
      to find a binary version of Pavel Demin's HPSDR code that runs on it
      - For now, use *only* the v0.95 ecosystem Zip image linked above
      - Insert the micro SD card and adapter included with the Red Pitaya
      Start Kit into your Windows computer, *format the FAT partition
      (wiping out v0.97)*, then extract Pavel Demin's entire SD Card Image
      to the root directory.
      - You can get back to a vanilla v0.97 later using images on the Red
      Pitaya web site <http://downloads.redpitaya.com/downloads/> .
      - Leave the other hidden partitions on the 4GB micro SD card alone,
      just format the FAT partition, do not delete or touch any other
partitions.
      - Extracting the Zip without first formatting the partition does not
      work.
      - Installing the v0.94 SDR receiver from the "Marketplace" link
      instead of from the Zip image does not work.
      - You don't have to use PowerSDR, which I found very hard to use.
      HDSDR seems much more intuitive to me.
      - You do not need to install Bonjour to access the Red Pitaya box
      from Windows; use the Windows command *arp -a* or your Router
      interface to find the IP address assigned to the Red Pitaya, then
      open your browser and enter that IP address as a URL
   3. Just use *FreqCalibration=1*.  I wasted a lot of time trying to get
   just the right calibration setting on the highest band, but then it messed
   up the other bands. Frequency calibration is not consistently "high" or
   "low" from band to band due varying sampling conversions, and since the
   Skimmer provides only one calibration setting, it's best to leave it alone.
   4. Frequency accuracy got better when I added a small 30mm fan via the
   plastic case, as recommended.  I did have to crimp on my own 0.1 mm fan
   connector.  Not well indicated on the board is that the positive pin of the
   fan connector is the pin closest to the center of the board.
   5. You can calibrate HDSDR very accurately using *Options | Calibration
   Settings* while tuned to WWV in EECS (AM) mode with AFC enabled.
   6. With OmniRig support, HDSDR can follow your transceiver's VFO and
   vice versa (Options -> CAT to radio (Omni-Rig) -> sync from Omni-rig
   (enable), sync to Omni-Rig (enable)
   7. Use Putty on Windows to get Unix command line access to the Red Pityaa
   (userid *root*, password *root*).
   8. Use *datetime -s "YYYY-MM-DD hh:mm:ss"* to set the internal Red Pitaya
   clock (in UTC).  Any error logs produced will then be properly
   time-stamped.  Do this first, then change the password.  I'd like to know
   how to automate setting the clock via NTP on v0.95 of this OS.
   9. Use the *passwd* command to change the root password.  Unfortunately,
   the new password is not saved between power cycles in this version of the
   OS, so it must be reset every time you power up the Red Pitaya. :-(
   10. The *top* command will display the Red Pitaya CPU utilization and
   memory use.  I never saw the CPU usage exceed 20%.  Type q to exit and
   return to the command line.
   11. Type exit to exit from the Unix command line shell
   12. If you open the IP address of the Red Pitaya in your browser, you'll
   see a nice friendly interface with an "Application Marketplace" link, but
   that software is not pre-installed on the SD card, it just redirects to
   http://bazaar.redpitaya.com/, and the SDR Receiver v0.94 on that site is
   old and does not run at all on v0.95.  DO NOT CLICK INSTALL!
   13. Despite W4KAZ's blog post (http://w4kaz.com/qth/?p=2786), the only
   SDR receiver build that seems to work with CW Skimmer Server and RTTY
   Skimmer Server at this time is 0.95 pre-built version.  I think there
   are still outstanding issues preventing the SDR code from running on any
   new version of the OS.
   14. I tried SDR-Console and WINRAD but they are not compatible.  Only
   HDSDR and PowerSDR worked for me, and only HDSDR works when the Skimmers
   are running.
   15. The *monitor -ams* command is documented to display Red Pitaya CPU
   temperature, but it isn't implemented in v0.95. :-(
   16. Error messages in the Red Pitaya are saved in in
   */tmp/log/redpitaya_nginx* (use the *tab* key to auto-complete long file
   names)
   17. Use *vi filename* to view a log file in a full screen Unix text
   editor
   18. Type colon (:) *q* [Enter] to exit the vi editor.

73,
Bob, N6TV


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