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You might peek at "weewx" to drive your weather station and add the "weewx-aprs" plugin ()

KM6LYW-3 operates with this combo

r,
-craig
KM6LYW

Is anyone running Xastir with a weather station? Can an?AcuRite Pro Weather Center be used?

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But, since it is open source, you *could* provide your own modifications and re compile....

Thanks David -
Turns out the main issues is that I forgot to set the filter for the server. doh! Set the filter and all that glorious traffic started appearing.

Unfortunately, I also discovered that the logging functionality of Direwolf apparently doesn't parse & log the incoming IS traffic like it does the pure RF traffic, which was I was ultimately hoping to achieve.
ah well...

Matt
N8SHA

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Hello Jason,

>?User-Guide.pdf

effort_level indicates the amount of effort to modify the frame to get a valid CRC.
0 means no attempt.
1 means try changing single bits. (default)
2 means try changing two adjacent bits.

I stand corrected and I apologize for that.? The Direwolf User Guide goes even farther and describes all this under section 12.3 "One Bad Apple Don't Spoil the Whole Bunch? ("FIX_BITS" option)".

the config:

> direwolf.conf /?

# It is sometimes possible to recover frames with a bad FCS.

# This applies to all channels.??

#

# 0? [NONE] - Don't try to repair.

# 1? [SINGLE] - Attempt to fix single bit error.? (default)

# 2? [DOUBLE] - Also attempt to fix two adjacent bits.

# ... see User Guide for more values and in-depth discussion.

I think this is where I got confused as the vanilla configuration is below and the "FIX_BITS" feature is commented out *but* that doesn't mean the default is off:
--
#
# It is sometimes possible to recover frames with a bad FCS.
# This applies to all channels.
#
#?????? 0? [NONE] - Don't try to repair.
#?????? 1? [SINGLE] - Attempt to fix single bit error.? (default)
#?????? ... see User Guide for more values and in-depth discussion.
#

#FIX_BITS 0
--

What am I missing?

So coming full circle, should FIX_BITS be disabled by default?? That's debatable as even with it off, it's acknowledged that AX.25 can and will still receive corrupted packets that have valid FCS16 checksums.? It would be interesting to see some sort of statistics data to see the probabilities if "FIX_BITS 1" really adds a lot more errors or not.? If you're really worried about it, go ahead and turn it off.

--David
KI6ZHD

David,

Are you referring to the FIX_BITS option?? If so, that's *not* the default setting to have it enabled.

Yes. By my read, the manual, the config, and the source itself, all indicate it is enabled by default.

>?User-Guide.pdf

effort_level indicates the amount of effort to modify the frame to get a valid CRC.
0 means no attempt.
1 means try changing single bits. (default)
2 means try changing two adjacent bits.

the config:

> direwolf.conf /?https://github.com/wb2osz/direwolf/blob/master/conf/generic.conf#L367

# It is sometimes possible to recover frames with a bad FCS.

# This applies to all channels.??

#

# 0? [NONE] - Don't try to repair.

# 1? [SINGLE] - Attempt to fix single bit error.? (default)

# 2? [DOUBLE] - Also attempt to fix two adjacent bits.

# ... see User Guide for more values and in-depth discussion.

and the source code:?

> https://github.com/wb2osz/direwolf/blob/master/src/audio.h#L391

#define DEFAULT_FIX_BITS RETRY_INVERT_SINGLE

What am I missing?

Thanks

I've now tried both powered & non-powered USB hubs and that solved the issue of running 3 USB soundcards; because a non-powered USB hub works, it doesn't seem to be a "out of power" issue. ?I'm still not quite sure why I can't plug the 3 USB soundcards using 3 of the 4 USB ports on the RPi4b.

After recompiling Direwolf with MAX_ADEVS set to 4, Now, when I go to 4 (four) USB soundcards, I get the same issue (regardless of whether I use a powered or non-powered USB hub). ?I also tried plugging in the 4th USB soundcard directly to the RPi4b but still have the same issue.

Does anyone have thoughts about how I may resolve this?

Thanks,
Jeffrey, KH6JUZ

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Hello Matt,

It is possible to configure Direwolf as a receive only client for data from an APRS-IS server? For example, APRSIS32 or AGWTracker can receive data from an APRS-IS server without connecting to a radio / tnc, etc. I'd like to use Direwolf in a non-RF mode for some development and testing.

Sure, there are lots of ways to do that.? You can configure Direwolf to use use STDIN as it's input soundcard yet not sent it any data.? Depending on your chosen operating system, you can also configure it to use PulseAudio's "default" soundcard yet never assign a PA "sink" so Direwolf will never receive any audio bits.? There are other possibilities here but it depends on the OS you're running it on.

--David
KI6ZHD

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Hello Jason,

The user is using Direwolf with the default settings which attempts to correct corrupted packets. While the documentation itself admits it is irresponsible to propagate corrupt data into the APRS-IS network, it doesn't take the same stance when passing it to clients which then unknowingly do so.

Are you referring to the FIX_BITS option?? If so, that's *not* the default setting to have it enabled.? Regardless, I generally agree with you but even with it off, APRS (aka AX.25) packet corruption does and will continue to happen to some very small degree due to how it was designed.? It's rare but also NOT zero.

Would you consider preventing Direwolf from passing potentially corrupt packets to connected clients? There could be a config flag that defaults to disabled if the functionally is truly desired. I am of the belief that people are doing it accidentally and would not choose to do so if they were aware. Perhaps there is some more elegant longer term solution where Direwolf can indicate a potentially corrupt packet when passing it to the client, or by adding?NOGATE/etc to the path automatically.

AX.25's FCS field uses a 16bit CRC to detect corruption but it's generally understood that it's fairly weak to protect a payload of 256 bytes.? There are some things you can do to improve on this like FX.25 and what not but remember, AX.25 was first imagined in the early 1980s.

--David
KI6ZHD

While looking at aprs.fi a little bit ago, I noticed a very similarly named station appearing on the map right next to an APRS object I manage. The call sign was slightly different and the status text was a little off, but the location was the same. After looking at the path and reaching out to the user who IGated it into the network, I learned they were using Direwolf as a TNC and YAAC as the frontend/APRS-IS client. You might already know where this is going...

The user is using Direwolf with the default settings which attempts to correct corrupted packets. While the documentation itself admits it is irresponsible to propagate corrupt data into the APRS-IS network, it doesn't take the same stance when passing it to clients which then unknowingly do so.?

Would you consider preventing Direwolf from passing potentially corrupt packets to connected clients? There could be a config flag that defaults to disabled if the functionally is truly desired. I am of the belief that people are doing it accidentally and would not choose to do so if they were aware. Perhaps there is some more elegant longer term solution where Direwolf can indicate a potentially corrupt packet when passing it to the client, or by adding?NOGATE/etc to the path automatically.

PS: I think there is a typo in the user manual in this section (APRTS-IS?):

Only error-free frames are digipeated or passed along to an APRTS-IS server. Propagating possibly
corrupt data would not be acting responsibly. Note that these frames are passed along to attached
applications. If they pass along data to someone else, it could be corrupt.

Thanks!

I am not sure what your expectations are?

It is possible to configure Direwolf as a receive only client for data from an APRS-IS server? For example, APRSIS32 or AGWTracker can receive data from an APRS-IS server without connecting to a radio / tnc, etc. I'd like to use Direwolf in a non-RF mode for some development and testing.

Thanks,

Matt - N8SHA

On 27/5/22 7:39 am, Lee Ligon wrote:
<snip>
SWR is less than 1.2:1 via the built in tuner.
</snip>

If your tuner is "in the shack" and your VSWR isn't that good on the antenna side of the tuner, the
RF has already made it into your faraday shield.
I much prefer having tuners (or couplers??) at the base of the antenna, or as near as practical to it.

Ian
VK1IAN

Thanks for the reply, David.? The dmesg log indeed shows USB resets.?
Antenna is a G5RV at the apex of a 50 foot tower directly behind the radio shack, which is inside a metal building that acts as a pretty good Faraday cage, SWR is less than 1.2:1 via the built in tuner.? Cables are not looped and the ferrites on the cables are tuned to the middle of the 20 meter band which is where I mostly operate.? Station grounding is as good as I can make it in the dry West Texas ground.? I am a retired systems engineer from what is now Harris Radio, I have designed and installed a ton of radio sites across the country, so am pretty confident in my ground system design.

Physically moving the Rpi seems to have made a significant difference in the problem, I think I need to build a shielded enclosure for it.

Thanks again!

KB5W?

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Ah.. you beat me replying to your post.? When you see errors like this in Direwolf, also look at the OS logs (/var/log/messages, dmesg, etc) and see if you're seeing USB resets.? USB cables with ferrites are a good start but you also have to look at:

?? - Antenna:
????? - How close is your antenna to your radio+computer setup?? Ideally, they are far apart and on? different horizontal plans
????? - use balanced antennas (dipoles, yagis, etc) as they create less SWR and RFI issues than non-balanced antennas (OCF wire antennas, non-resonant verticals, etc)
????? - What is the SWR of your antenna?

?? - Radio
????? - Run lower power on your radio can help as a temporary solution

?? - Cable routing
?????? - Avoid creating "clean" cabling where you're looping your cables to look pretty.? Those loops become effective antennas!? You can do alternatives like figure eights, etc. to manage longer cables.

?? - Ferrites
????? - Put *frequency appropriate* chokes with as many turns as reasonable on ALL cables going in/out of your cables going in/out of your computer, radio. This includes audio cables, network cables, power cables, RF cables, etc.
???????? - NOTE that the chokes on your existing USB cables might NOT be suitable for the frequencies you're operating on (HF, VHF, UHF, etc.

?? - Grounding and shielding
????? - How is your RF grounding for your station??? Please remember electrical grounding is different than RF grounding
????? - See


ARRL also publishes some books on combating RFI but I can't comment on them as I've never read any of them

--David
KI6ZHD

Sorry for answering my own post.?

I believe I am seeing RF getting into the USB port, even though I am using good quality shielded USB cables with ferrite chokes on both ends of every cable.

I am running Direwolf on a Raspberry Pi with linbpq.? I keep getting the following errors on my HF packet port that is connected to an IC-7300:

[0] AJ0R>KB5W-1:(RR cmd, n(r)=0, p=1)
Hamlib Error: rig_set_ptt command for channel 0 PTT
Communication timed out
frame.c(439):icom_transaction return(0)
icom.c(4844):icom_set_ptt return(-5)
rig.c(3023):rig_set_ptt return(-5)
[0L] KB5W-1>AJ0R:(RR res, n(r)=0, f=1)
Hamlib Error: rig_set_ptt command for channel 0 PTT
Communication timed out
frame.c(439):icom_transaction return(0)
icom.c(4844):icom_set_ptt return(-5)
rig.c(3023):rig_set_ptt return(-5)

Happens about every fourth time the rig keys up. The rig still keys up and transmits usable packet.? Is there anything that I need to do, or can do about the errors?

Thanks for the help!

The documentation contains many examples of interfacing to a radio.



When using a Raspberry Pi, you would probably want to start with:

?


73,
John WB2OSZ