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Has there been any successful deployment of CCW on a raspberry pi? #raspberrypi #pi #linux

Wade Anthony
 

Hi all,

I have been wrestling with this for a while so hope some others might have worked it out.

I have a raspberry pi 3 which I use 'headless' for digital modes in the field with my 817. more here http://wadeabout.com/blog/portablepi-a-raspberrypi-for-amateur-radio-portable-opers

however to add the cherry to the top of /p I would love to get CCW working on it.

Here are the steps I have taken:

Installed Exagear to emulate an i686 environment,
installed wine
installed winetricks
dotnet3.5sp and dotnet35
loaded ccw under wine.

Issues:

CCW crashes 90% of the time IF it goes pass the setup / config screen
zero recognition of the interface to the radio by USB for rig control


Ideas??

W

VK1MIC

Greg_M6ORT
 

I've got access to Crossover for Linux by Codeweavers.  I can try that instead of vanilla Wine or could try PlayonLinux.  Sometimes they seem to offer better integration than the plain Wine plus Codeweavers have decent debugging enabled.  It sounds like it is going to be one of those let's see between us if we can find what is missing from the packages that is stopping things running arrangements.
If I do get time as per the other thread post I'll let you know.
73 de Greg
M6ORT

Nick G4IRX
 

I briefly looked into decoding and encoding with FLdigi. What we need it details of the checksum calculation that is appended to the packets an used for validation when decoding.

Personally I think trying to run this under arm Linux on a Pi is going to be too resource heavy to work reliably.

73
Nick

WA8LMF
 

On 4/21/2018 12:20 PM, Nick G4IRX wrote:
I briefly looked into decoding and encoding with FLdigi. What we need it details of the checksum calculation that is appended to the packets an used for validation when decoding.

Personally I think trying to run this under arm Linux on a Pi is going to be too resource heavy to work reliably.

73
Nick
_

Why oh why do people keep trying to beat a round peg into a square hole?    It's intrinsically a kludge to run native Windows programs under Linux.  Trying to do this on a Ras Pi just makes it doubly kludgy since you don't have a native display, don't have a native keyboard/mouse,  don't have enough USB ports, etc.   By the time you acquire the rat's nest of USB hubs, mini HDMI cables, externalHDMI monitor (or VGA mon plus HDMI-to-VGA converter, etc) you will have spent far ;more than just installing the Messenger app on a cheap 7' or 8" Windows tablet that sells for less than $100.     

If you do want to kludge FLdigi to do Messenger-mode packets, here are the details you need.   this is a post made years ago by G4HYG


How it works...APRS over PSK-63     Revised 23 Nov 2014
   

Previous attempts to use the PSK modes for APRS using an add-on that the late Roger Barker G4IDE wrote for UI_View have been disappointing as no error checking or AFC was used in the original add-on. This resulted in incorrect callsigns and positions appearing on the UI-View map and APRS-IS.

I wanted to improve on this as the performance of HF 300 bd packet has been poor during the recent sunspot minimum.

So how does it work...

Let's say we want to send the following APRS packet:

G4HYG>APSK-63:=5332.76N/00225.91W&Testing APRS Messenger v2.26 on 10.1497 MHz

First the program calculates a checksum using the CRC-16 Modbus algorithm. For the above APRS packet it works out in hex as: 4B60
This is then added to the packet:

G4HYG>APSK-63:=5332.76N/00225.91W&Testing APRS Messenger v2.26 on 10.1497 MHz4B60

A start and end flag "~" tilde character is added at the start and end of the packet. This is similar to what is used in a AX.25 packet frame.
This gives:

~G4HYG>APSK-63:=5332.76N/00225.91W&Testing APRS Messenger v2.26 on 10.1497 MHz4B60~

To overcome any data corruption in the receiver due to the AFC locking on or AGC on a strong signal eight dots are added at the start ........
(Five dots in early APRS Messenger versions, eight dots from v 2.35 to reduce packet errors). A space is added after the final "~" tilde character so that the start and end tilde characters can be found in a stream of random noise characters.

We finally transmit the following packet:

........~G4HYG>APSK-63:=5332.76N/00225.91W&Testing APRS Messenger v2.26 on 10.1497 MHz4B60~

When this is received at another station it could be corrupted by interference or noise.

A typical received signal follows:

...~G4HYG>APSK-63:=5332.76N/00225.91W&Testing APRS Messenger v2.26 on 10.1497 MHz4B60~ kt e h

Note that two of the dots at the start are missing and "kt e h" has been added at the end as the receiver PSK squelch was closing.

The receive side of the program now looks for the start and end "~" tilde flags and extracts the text between them:

G4HYG>APSK-63:=5332.76N/00225.91W&Testing APRS Messenger v2.26 on 10.1497 MHz4B60

The last four characters are extracted and a CRC-16 Modbus checksum is calculated on what is left. This checksum is compared with the extracted four characters to confirm that the received packet is the same that sent by the sender. In this case it is:

4B60 is the same as 4B60 so the packet is confirmed as correct.

The packet is now displayed on the screen even if it has errors so that it can be manually read. If the packet has checked OK then it is sent to the APRS-IS:

G4HYG>APSK-63:=5332.76N/00225.91W&Testing APRS Messenger v2.26 on 10.1497 MHz

73,

Chris, G4HYG











Chris Moulding
 

Thanks for finding that, Stephen. I remember writing it but couldn't remember where it was posted. I recall one of the FlDigi developers was interested in adding APRS over digimodes to FlDigi in the early days but nothing happened.

I've tried using Android tablets for amateur radio programs but it's never really been a good experience. I now use a Linx 7 Windows 8 tablet I bought a few years back to run Windows programs reliably. I even used it recently to test the updates to the messaging routine between the main PC and the tablet.

I've used Raspberry Pi in various versions for APRS igates and a WebSDR server but all five are now in my desk drawer gathering dust. I've nothing against them but I agree it's the peripherals needed that made me look for alternatives.

Regards,

Chris

Greg_M6ORT
 

With respect Stephen many people may only be able to afford a raspberry pi and may be existing on second hand or loan gear.

Personally I prefer not to tie up my decent PC hardware most of which I share with my kids doing single task work, thus the raspberry pi usage which is powerful enough for most tasks, plus the majority of my hardware is running Linux anyhow.  I also have the associated hardware peripherals in abundance and have VNC running on all my pis very successfully to allow remote working.

So... Having tried the Pi3B+ with latest Stretch, running Exagear and Wine 2.0 I can confirm it is a no go.

The settings in the main loading screen don't save in between usages on the pi, although I got round this using nano and updating the txt files manually. 

I was able to get it to TX mode eventually, but that is point at which it hung and I had to kill it from the command line.

I was able to get APRS-IS connection ok.

To be honest the best solution for someone wanting to run this as a stand alone HF RX igate for instance would be to spend a few £££ extra and get a Windows mini PC / TV Box which can be had for £75 with Windows and to which you can install the windows binaries for TightVNC to get round the lack of Remote Desktop in Windows Home Edition.  Those devices have x86 Atom Processors and can run nicely.  I use one for my WiresX HRI 200 setup to good effect and a slightly more powerful one to do WXSat work.  No Wine, no x86 emulator.

With regards to any suggestion a Pi3B+ isn't up to it processor wise I can confirm the program itself took up no more than 29% of processing time.

If I do anything for M0BPQ I'll using one of those mini Windows PCs for sure.

73 de Greg
M6ORT



Wade Anthony
 

I wholeheartedly agree re price / affordability. I run an old xp laptop at home but can do all digital modes in the bush /p bar CCW aprs and winlink - however pat looks like a goer on the pi with ardop. You don’t have to go far from major capital cities in VK to have no mobile phone service. For me I wanted the short message capability as well as camp site location posting that ccw offers. I too tried exagear.

Sadly anything bigger than the pi form factor (and 5v Power ) is pushing it.

73

VK1MIC /P. I’m walking back from a SOTA summit right now

Wade.

Wade Anthony
 

I wonder - and am shooting from
the hip here - if in my case FLDIGI would help. We have seen how psk63 can work from say a tablet using a wolphilink ... I set the pi on fldigi, on MFSK16 using the VK 40 m settings of 7045.2 1200  , then copied the exact text my CCW broadcasts. 

See pic below. NB in the screen shot it says psk63 I changed it after the picture. 

Propergation to my regular Igate by VK2IO-63 isn’t great at the moment so I can’t test what comes out the other end or if it would be Igated.   This is done becuse I love hf aprs and CCW not as a knock to Chris who as done a fabulous job - I want to use it more but can’t - as above. 

Chris Moulding
 

It is possible to generate a fixed beacon packet with APRS Messenger, read it with another device using FlDigi then cut and paste the received message including the tilde ~ symbols and the CRC-16 checksum as a memory message in FlDigi. Don't forget to include the space after the last tilde ~ character.

I know this works because it's how I used to test the decoding in the first versions of APRS Messenger and time the message using different modes.

Regards,

Chris

Wade Anthony
 

Thanks Chris !!  Any way I can generate a check sum? 
And would it change beacon to beacon? Even mobile? 
W




On 24 Apr 2018, at 17:42, Chris Moulding <chrism@...> wrote:

It is possible to generate a fixed beacon packet with APRS Messenger, read it with another device using FlDigi then cut and paste the received message including the tilde ~ symbols and the CRC-16 checksum as a memory message in FlDigi. Don't forget to include the space after the last tilde ~ character.

I know this works because it's how I used to test the decoding in the first versions of APRS Messenger and time the message using different modes.

Regards,

Chris

Chris Moulding
 

If the same fixed beacon is used then the checksum doesn't vary.

Used mobile then it will vary as the GPS position changes. The same with messages.

APRS Messenger uses a CRC-16 Modbus checksum and there are many code samples on the internet allowing you to generate a checksum in the language of your choice.

APRS Messenger is written in Visual Basic 6 and I can post the code routine on here later today.

Regards,

Chris

Greg_M6ORT
 

Just to conclude the discussion from my end.

I gave the raspberry pi a few more goes and then gave up.

I have got a nice z83 TV box running windows 10 that can run off 12v/1.5A so could be battery powered working.

The footprint isn't too much bigger than a Pi and it has 32GB storage and 2GB RAM which seems to be OK.  I use a similar box for my WiresX node.  For the project that M0BPQ and I have been discussing i.e. an HF Rx igate it seems to be ideal.  RAM and Processor (4 core Atom z8350) definitely ok for this.  More powerful systems exist in the TV box market, I have one running my WXSat decodes but the power draw is heavier and they're larger.

I think M0BPQ is likely to use it for testing with a CCW SDR given it is for RX only.

I'll report back on any developments / system overheads etc when signals are being received. I've just been setting up the box and APRS Messenger and VNC software. I'll be handing it over on Friday.

Not sure if this might be a portable option for someone if they're carrying a 5200mAh LiPoFe and can use a converter to get a stable 12v.

Anyhow, just wanted to conclude what I had found.

I am following the Fldigi stuff with interest.

Regards
Greg
M6ORT

Wade Anthony
 

Thanks Greg - That does sound like an option.

Just to be clear on my personal needs and thus why I was looking at the FLDIGI solution - I do not want a tracker that is constantly pumping out beacons as I move - It is for " I have set up camp and I am alive or, I am changing plans and diverting to X etc.

The small and non insurmountable obstacles are as follows for the FLGIDI solution:

* correctly formatting the packet 'string' for the mode you wish to use - PSK63 or MFKS16 etc.
* Checksum - this is a small 4 (I think) character block that is added to the end of the string.

Both of these can be seen if you look at the screen output for say DroidPSK using PSK-63 and the APRS macro or decode using FLDIGI on rx of some one else's packet.


Once you set up in the field you can hand type the string from a template - then the checksum needs to be added - this is static ONLY if the station is static - each location needs a new one. And I am assuming each message that contains different text needs a new one.

W

VK1MIC



On 3 May 2018 at 09:24, Greg_M6ORT <r_wellington@...> wrote:
Just to conclude the discussion from my end.

I gave the raspberry pi a few more goes and then gave up.

I have got a nice z83 TV box running windows 10 that can run off 12v/1.5A so could be battery powered working.

The footprint isn't too much bigger than a Pi and it has 32GB storage and 2GB RAM which seems to be OK.  I use a similar box for my WiresX node.  For the project that M0BPQ and I have been discussing i.e. an HF Rx igate it seems to be ideal.  RAM and Processor (4 core Atom z8350) definitely ok for this.  More powerful systems exist in the TV box market, I have one running my WXSat decodes but the power draw is heavier and they're larger.

I think M0BPQ is likely to use it for testing with a CCW SDR given it is for RX only.

I'll report back on any developments / system overheads etc when signals are being received. I've just been setting up the box and APRS Messenger and VNC software. I'll be handing it over on Friday.

Not sure if this might be a portable option for someone if they're carrying a 5200mAh LiPoFe and can use a converter to get a stable 12v.

Anyhow, just wanted to conclude what I had found.

I am following the Fldigi stuff with interest.

Regards
Greg
M6ORT




--
--

Wade

VK1MIC.com

EvenChu@...
 
Edited

Hi...in our case what we need it details of the checksum calculation that is appended to the packets an used for validation when decoding.Personally I think trying to run this under arm Linux on a Pi is going to be too resource heavy to work reliably.

circuit card assembly