Re: It was "fine", then... strange behavior #draws #setup #betaimage

Basil Gunn

Hi Gayland,
Thank you for testing the DRAWS board.

This email only addresses your audio problem. First uncommenting the
dtparam=audio=on line in the /boot/config.txt should not cause your
system to become unusable. I'm guessing there was something else that
was changed/added in the config.txt file that caused that.

I have notes in the VERIFY_CONFIG doc & the Xastir README describing
what you need to do for enabling analog & HDMI sound on the RPi. This
functionality is unrelated to any of the UDRC/DRAWS hats.

I have added notes in the file near the end for "Test
RPi sound"

Also please check the xastir under "Configure Audio"


Gayland Gump <> writes:

I haven't the sophisticated knowledge of how the DRAWS & UDRC perform their
magic but I have the following observations.

Out of the box, the DRAWS would not work with my Yaesu 857D when running
fldigi. I believe that the PTT wasn't working immediately after I did the
initial configuration of fldigi but I can't be sure. Thinking back a
couple years or so when I first got my first UDRC I began to suspect the
ALSA settings. Examining the UDRC settings and comparing them to the DRAWS
I tried changing a couple of the parameters on the DRAWS to correspond to
those on the UDRC. After a couple changing a single parameter at a time
with no change in outcome.

I realized that on the UDRC I had the on board audio turned on. In order
to model the working UDRC, I decided to activate the onboard audio using
the "dtparam=audio=on" parameter in the /boot/config.txt file on the
DRAWS. I had no definite rationale for doing this other than to eliminate
another difference in the UDRC and DRAWS configurations. The impact of
making that change in situ on the DRAWS was disastrous as on a reboot the
system was entirely un-useable. I immediately reversed that change and
returned to pursuing the ALSA settings.

As my earlier approach of changing single ALSA parameters had not yielded
any change in fldigi's performance, I did a wholesale change of the DRAWS
alsa settings to those that were currently in place on my working UDRC.
After completing these changes, the DRAWS was able to transmit and
receive. There are still some issues though.

First, there is a significant difference in SNR reports on the UDRC vs the
DRAWS. DRAWS levels appear to be 10 or more DB lower than those being
reported by fldigi on the UDRC. As all I do to obtain these observations
is move the 6-pin DIN connector back and forth between the UDRC and DRAWS
using identical ALSA settings, I'd like to know what might be causing the
differences in the SNR reports between those devices.

Another difference, which I note between the DRAWS and UDRC which may well
be related to the level differences is in the fldigi waterfall display. To
the best of my knowledge the applicable waterfall settings on the DRAWS and
the UDRC but the displays are significantly different. I've got my UDRC
set so that the waterfall shows a constant noise level. Lots of others
seem to prefer having a noiseless screen that only display's stronger
signals. I find that by leaving the display set so that it displays noise
I am able to visually identify some weak FSQ signal patterns.

I'd also like to know what it takes to get the on board audio working on
the DRAWS after all some of the software running on the DRAWS provides
audio cues that it might be nice to use. Of course assuming that those
cues can be delivered to the on board audio for presentation.

I want to applaud all of NWDR's efforts at bringing us some very cool and
useful tools. I also recognize that providing documentary support for
these tool is extremely challenging given the resources available. Given
the constraints, I know that it is a lot to expect that NDWR keep in mind
that we users including early adopters often don't have the necessary depth
of knowledge that NDWR folks have and expecting us to know about
non-standard applications (e.g. chrony vs ntp) or even basic linux system
operations need to be carefully considered assumptions.

Finally, I'd like to find out if NWDR has any ideas why I'd be seeing the
differences in SNR that appear between the DRAWS and UDRC? What have I
overlooked or just don't know about?

Thanks again for your time and attention.


On Wed, Dec 19, 2018 at 7:07 AM Jack Spitznagel <> wrote:

Basil, John, All,

Initially, Beta 5 seemed to work out of the box but I ran into some DRAWS
audio and keying strangeness that is baffling me after 3 tries at
installing from newly flashed microSD cards and following Basil's latest
procedure on GitHub. Hope you can provide insight. Rig is a CAT controlled

Tested Direwolf with Xastir and YAAC with both RX and TX successfully, but
noticed the audio was a bit hot - signal here looked normal on the SpecLab
so I left it alone.

Then disabled AX.25/direwolf (script) and configured fldigi and wsjt-x.
Both programs worked in receive but the TX audio to the IC-7000 was very
"hot". Put fldigi in tune then to bring the ALC reading as close to zero as
possible by reducing audio levels with the PCM drive control. As audio
level is reduced - the ALC starts to "pump", as did the power out
indication - unexpectedly, there was a increase of noise on audio and
harmonic spikes got higher as level of signal was reduced. Returned levels
to where they had been and meter indications returned to where they were
before. Was able to have a PSK31 QSO and got no comment about the signal

I re-enabled AX.25/Direwolf using the script. Now both Xastir and YAAC no
longer would transmit audio. When the rig is keyed, the TX LED on the rig
flashes 3-4 times quickly and there is no modulation of the FM carrier.
Reboot did not change behavior. Going back to non-AX25 mode, now fldigi
would key the radio, but no modulation occurred.

Re-installation of the DRAWS beta 5 from the ground up (x2) did not help -
none of the programs transmit audio and symptoms are the same.

To be sure rig was OK, I hooked up an old SIgnaLink to a laptop, ran HRD
and it drove and keyed the rig just fine. So I have to assume that the
problem is software or DRAWS hardware related.

Where should I be looking to fix the audio? The keying?
Settings should not so brittle. Thanks in advance,
J Spitznagel - KD4IZ
Science River LLC

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