Author Topic: New ATOM Ground station SDR Detection Issues  (Read 13704 times)

kevkdg

New ATOM Ground station SDR Detection Issues
« on: December 27, 2020, 02:05:56 pm »
Hi,

PWUKFUF/UKRUF is a new ATOM ground station, previously only an OGN station.

Having a few issues with detecting SDR's as pasted below and being looked into by the PAW Team (Keith/Chris/Lee).

However, are there any useful commands that can be run without the need to run config every time.  For example to reboot the Pi, check the SDR status's?

Regards

Kevin

Config From 19th Dec (First time running after setting up ground station hardware and interestingly the FLARM antenna was NOT plugged into USB Bottom Right but into the Top Left):
 
(15:32:36) FILESYS   : Mount RW                                                                                                       
Stopping Services                                                                                                                     
Do not plug in or remove any SDR dongles whilst this configuration script is running.                                                 
It is strongly advised to have the SDR's plugged in and then reboot the Pi before running this configuration script.                 
Found 2 SDR's:                                                                                                                       
   USB Port Top Left    : SDR detected  ID=1  currently unallocated
   USB Port Bottom Left : no SDR detected                                                                                             
   USB Port Top Right   : no SDR detected                                                                                             
   USB Port Bottom Right: SDR detected  ID=0  currently allocated to OGN/FLARM reception on 868Mhz
One SDR is currently configured for OGN and you have an unallocated SDR which could be used for ADS-B reception.                   
 
Config From 20th Dec (Picked up both dongles and assigned correct ID’s as per the Instruction Manual – ID=1 to OGN/FLARM and ID=0 to ADSB AFTER initially complaining of conflicting SDR serial numbers and following a couple of reboots):
 
(19:47:31) FILESYS   : Mount RW                                                                                                                                                                                   
Stopping Services                                                                                                                                                                                                 
Do not plug in or remove any SDR dongles whilst this configuration script is running.                                                                                                                             
It is strongly advised to have the SDR's plugged in and then reboot the Pi before running this configuration script.                                                                                               
Found 2 SDR's:                                                                                                                                                                                                     
   USB Port Top Left    : SDR detected  ID=1  currently allocated to OGN/FLARM reception on 868Mhz
   USB Port Bottom Left : no SDR detected                                                                                                                                                                         
   USB Port Top Right   : no SDR detected                                                                                                                                                                         
   USB Port Bottom Right: SDR detected  ID=0  currently allocated to ADS-B reception on 1090Mhz
One SDR is currently configured for OGN and the other is configured for ADS-B reception.                                                                                                                           
                                                                                                                                                           
 
No tinkering post the above config.... until today (27th) as noticed FLARM was not working:
 
Config Attempt 1 (27th Dec following FLARM dropout) – Issue appears to be the same serial numbers allocated to both SDR’s – How can this happen given nobody has done anything on the Pi since the above config run on 20th?:
 
(11:40:57) FILESYS   : Mount RW                                                                                                                                                                                   
Stopping Services                                                                                                                                                                                                 
Do not plug in or remove any SDR dongles whilst this configuration script is running.                                                                                                                             
It is strongly advised to have the SDR's plugged in and then reboot the Pi before running this configuration script.                                                                                               
Found 2 SDR's:                                                                                                                                                                                                     
WARNING: Either an SDR has no serial number or two or more SDR's have identical serial numbers.                                                                                                                   
The configuration can only continue once all SDR's have unique serial numbers assighned.                                                                                                                           
The SDR's will now have their serial numbers changed to randomly assigned values and a reboot will be required.                                                                                                   
If any of the SDR's are plugged into a powered USB hub then the hub will also need to be powered down at the same time.                                                                                           
Proceed with updating the serial numbers and reboot [Y/n]: y                                                                                                                                                       
SDRs renamed - rebooting in 10 seconds                                                                                                                                                                             
Please rerun config afterwards
 
Config Attempt 2 (Following Re-Boot) Picked up ADSB/1090 in correct USB Port:
 
(11:45:53) FILESYS   : Mount RW                                                                                                                                                                                   
Stopping Services                                                                                                                                                                                                 
Do not plug in or remove any SDR dongles whilst this configuration script is running.                                                                                                                             
It is strongly advised to have the SDR's plugged in and then reboot the Pi before running this configuration script.                                                                                               
Found 1 SDR:                                                                                                                                                                                                       
   USB Port Top Left    : no SDR detected                                                                                                                                                                         
   USB Port Bottom Left : no SDR detected                                                                                                                                                                         
   USB Port Top Right   : no SDR detected                                                                                                                                                                         
   USB Port Bottom Right: SDR detected  ID=0  currently allocated to ADS-B reception on 1090Mhz
SDR's serial changed to 868                                                                                                                                                                                       
Do you want to set a Password (recommended first time) [y/N]:
 
Config Attempt 3 (Now only picks up FLARM in correct USB Port but is assigning ID=0 which was the ADSB assigned number) - Not sure why ADSB/1090 SDR is no longer being detected as it was only a few minutes ago:
 
(11:47:12) FILESYS   : Mount RW                                                                                                                                                                                   
Stopping Services                                                                                                                                                                                                 
Do not plug in or remove any SDR dongles whilst this configuration script is running.                                                                                                                             
It is strongly advised to have the SDR's plugged in and then reboot the Pi before running this configuration script.                                                                                               
Found 1 SDR:                                                                                                                                                                                                       
   USB Port Top Left    : SDR detected  ID=0  currently allocated to OGN/FLARM reception on 868Mhz
   USB Port Bottom Left : no SDR detected                                                                                                                                                                         
   USB Port Top Right   : no SDR detected                                                                                                                                                                         
   USB Port Bottom Right: no SDR detected                                                                                                                                                                         
 
Config Attempt 4:
 
(11:48:16) FILESYS   : Mount RW                                                                                                                                                                                   
Stopping Services                                                                                                                                                                                                 
Do not plug in or remove any SDR dongles whilst this configuration script is running.                                                                                                                             
It is strongly advised to have the SDR's plugged in and then reboot the Pi before running this configuration script.                                                                                               
Found 1 SDR:                                                                                                                                                                                                       
   USB Port Top Left    : SDR detected  ID=0  currently allocated to OGN/FLARM reception on 868Mhz
   USB Port Bottom Left : no SDR detected                                                                                                                                                                         
   USB Port Top Right   : no SDR detected                                                                                                                                                                         
   USB Port Bottom Right: no SDR detected                                                                                                                                                                         

« Last Edit: December 27, 2020, 02:09:17 pm by kevkdg »

steveu

Re: New ATOM Ground station SDR Detection Issues
« Reply #1 on: December 27, 2020, 05:24:17 pm »
The important thing is NOT to mess with the software on it...

The only command I can suggest is lsusb. All it does is ask the question, what's happening in USB land on this Pi?

Code: [Select]
pi@ognpaw:~ $ lsusb
Bus 001 Device 006: ID 1a2c:2124 China Resource Semico Co., Ltd                                                                                                                           
Bus 001 Device 005: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T                                                                                                               
Bus 001 Device 004: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T                                                                                                               
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter                                                                                         
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.                                                                                                                             
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub                                                                                                                           
pi@ognpaw:~ $

Here you can see the question has been asked and the Pi says there are two SDRs connected, and gives the device ID and the manufacturer.

There is also a keyboard connected, as I am a terminal based dinosaur.

If this list only gave you one SDR, then you know there is an issue.

My suggestion, not endorsed by PilotAware - I used short USB extension leads so the weight and bending action of the heavy SDR would not damage the motherboard. If the USB connector flexes, this may cause an issue. I could be wrong and clueless though.

 

kevkdg

Re: New ATOM Ground station SDR Detection Issues
« Reply #2 on: December 27, 2020, 06:24:03 pm »
I ran the lsusb query and then did a sudo reboot and ran config various times, as even when it correctly picked up both SDR's it didn't tune the FLARM, so it looks like it lost it again.

Ended up back where I started with only FLARM up and running, except it seems to one minute locate FLARM SDR in the correct USB socket (Top Left) but then another timein the Bottom Right USB which is where the 1090 antenna SDR is connected.  however it seems to tune FLARM OK even when i thinks it is connected to the 1090 USB Port which I don't think it would be able to do using the 1090 antenna!

I am wondering whether it might be a power supply issue??

pi@ognpaw:~ $ lsusb
Bus 001 Device 005: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T                                                                                                                                         
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter                                                                                                                   
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.                                                                                                                                                       
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

sudo roboot

Now it picks up 2 SDR's:

(18:32:09) FILESYS   : Mount RW                                                                                                                                                                                   
Stopping Services                                                                                                                                                                                                 
Do not plug in or remove any SDR dongles whilst this configuration script is running.                                                                                                                             
It is strongly advised to have the SDR's plugged in and then reboot the Pi before running this configuration script.                                                                                               
Found 2 SDR's:                                                                                                                                                                                                     
WARNING: Either an SDR has no serial number or two or more SDR's have identical serial numbers.                                                                                                                   
The configuration can only continue once all SDR's have unique serial numbers assighned.                                                                                                                           
The SDR's will now have their serial numbers changed to randomly assigned values and a reboot will be required.                                                                                                   
If any of the SDR's are plugged into a powered USB hub then the hub will also need to be powered down at the same time.                                                                                           
Proceed with updating the serial numbers and reboot [Y/n]:

(18:36:08) FILESYS   : Mount RW                                                                                                                                                                                   
Stopping Services                                                                                                                                                                                                 
Do not plug in or remove any SDR dongles whilst this configuration script is running.                                                                                                                             
It is strongly advised to have the SDR's plugged in and then reboot the Pi before running this configuration script.                                                                                               
Found 2 SDR's:                                                                                                                                                                                                     
WARNING: Either an SDR has no serial number or two or more SDR's have identical serial numbers.                                                                                                                   
The configuration can only continue once all SDR's have unique serial numbers assighned.                                                                                                                           
The SDR's will now have their serial numbers changed to randomly assigned values and a reboot will be required.                                                                                                   
If any of the SDR's are plugged into a powered USB hub then the hub will also need to be powered down at the same time.

pi@ognpaw:~ $ lsusb
Bus 001 Device 005: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T                                                                                                                                         
Bus 001 Device 004: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T                                                                                                                                         
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter                                                                                                                   
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.                                                                                                                                                       
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Now it has assigned them correctly:

(18:46:20) FILESYS   : Mount RW                                                                                                                                                                                   
Stopping Services                                                                                                                                                                                                 
Do not plug in or remove any SDR dongles whilst this configuration script is running.                                                                                                                             
It is strongly advised to have the SDR's plugged in and then reboot the Pi before running this configuration script.                                                                                               
Found 2 SDR's:                                                                                                                                                                                                     
   USB Port Top Left    : SDR detected  ID=1  currently allocated to OGN/FLARM reception on 868Mhz
   USB Port Bottom Left : no SDR detected                                                                                                                                                                         
   USB Port Top Right   : no SDR detected                                                                                                                                                                         
   USB Port Bottom Right: SDR detected  ID=0  currently allocated to ADS-B reception on 1090Mhz
One SDR is currently configured for OGN and the other is configured for ADS-B reception.                                                                                                                           

Test tuning however does not pick up the FLARMM
...
Test tuning of rtl-sdr device=1                                                                                                                                                                                   
                                                                                                                                                                                                                   
Testing --ppm=0 --gain=0                                                                                                                                                                                           
Not enough data was collected                                                                                                                                                                                     
                                                                                                                                                                                                                   
Testing --ppm=0 --gain=5                                                                                                                                                                                           
Not enough data was collected                                                                                                                                                                                     
                                                                                                                                                                                                                   
Testing --ppm=0 --gain=10                                                                                                                                                                                         
Testing --ppm=0 --gain=15                                                                                                                                                                                         
Testing --ppm=0 --gain=20                                                                                                                                                                                         
Testing --ppm=0 --gain=25                                                                                                                                                                                         
Testing --ppm=0 --gain=30                                                                                                                                                                                         
Testing --ppm=0 --gain=35                                                                                                                                                                                         
Testing --ppm=0 --gain=40                                                                                                                                                                                         
Testing --ppm=0 --gain=45                                                                                                                                                                                         
Testing --ppm=0 --gain=50                                                                                                                                                                                         
Not a valid number: _UNDEF_ for option ppm                                                                                                                                                                         

So re-ran config and back to picking up only 1 SDR (ADSB in the correct Bottom Right USB):                                                                                                                                                                                                                  
                                                                                                                                                                                                                   
Starting Services

(18:48:45) FILESYS   : Mount RW
Stopping Services
Do not plug in or remove any SDR dongles whilst this configuration script is running.
It is strongly advised to have the SDR's plugged in and then reboot the Pi before running this configuration script.
Found 1 SDR:
   USB Port Top Left    : no SDR detected
   USB Port Bottom Left : no SDR detected
   USB Port Top Right   : no SDR detected
   USB Port Bottom Right: SDR detected  ID=0  currently allocated to ADS-B reception on 1090Mhz
SDR's serial changed to 868

So re-ran config again still picking up 1 SDR BUT this time OGN/FLARM in correct Top Left USB and correctly tunes it:   

(18:49:55) FILESYS   : Mount RW
Stopping Services
Do not plug in or remove any SDR dongles whilst this configuration script is running.
It is strongly advised to have the SDR's plugged in and then reboot the Pi before running this configuration script.
Found 1 SDR:
   USB Port Top Left    : SDR detected  ID=0  currently allocated to OGN/FLARM reception on 868Mhz
   USB Port Bottom Left : no SDR detected
   USB Port Top Right   : no SDR detected
   USB Port Bottom Right: no SDR detected
...
Testing --ppm=-0 --gain=40                                                                                                                                                                                         
Capture @5ppm inrange=43 outrange=0                                                                                                                                                                               
Frequency Capture Improvement = 42 -> 43                                                                                                                                                                           
Receiver Xtal correction = 0-0.474 =  -0.474 (0.379) ppm [102]                                                                                                                                                     
setting APRS_SDR_PPM=-0                                                                                                                                                                                           
setting APRS_SDR_GAIN=40

So, re-ran config again still picking up 1 SDR OGN/FLARM but now thinks it is positioned in the USB in the Bottom Right instead of Top Left but seems to tune it OK (Bottom Right is 1090):   

(18:59:00) FILESYS   : Mount RW                                                                                                                                                                                   
Stopping Services                                                                                                                                                                                                 
Do not plug in or remove any SDR dongles whilst this configuration script is running.                                                                                                                             
It is strongly advised to have the SDR's plugged in and then reboot the Pi before running this configuration script.                                                                                               
Found 1 SDR:                                                                                                                                                                                                       
   USB Port Top Left    : no SDR detected                                                                                                                                                                         
   USB Port Bottom Left : no SDR detected                                                                                                                                                                         
   USB Port Top Right   : no SDR detected                                                                                                                                                                         
   USB Port Bottom Right: SDR detected  ID=0  currently allocated to OGN/FLARM reception on 868Mhz
...
Testing --ppm=-0 --gain=40                                                                                                                                                                                         
Capture @5ppm inrange=43 outrange=0                                                                                                                                                                               
Frequency Capture Improvement = 41 -> 43                                                                                                                                                                           
Receiver Xtal correction = 0-0.466 =  -0.466 (0.369) ppm [102]                                                                                                                                                     
setting APRS_SDR_PPM=-0                                                                                                                                                                                           
setting APRS_SDR_GAIN=40

pi@ognpaw:~ $ lsusb
Bus 001 Device 005: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
« Last Edit: December 27, 2020, 07:19:01 pm by kevkdg »

steveu

Re: New ATOM Ground station SDR Detection Issues
« Reply #3 on: December 27, 2020, 08:11:36 pm »
All I can suggest is that you have intermittent connections to the SDRs, or they are about to croak.

The only thing to double check is that the frequency of the aerial is the correct one in the config program.

You could test the USB sockets by moving to different ones. You need to check the config program has the right SDR + aerial for the socket. If not, the procedure will not receive the signal because of a mismatch, AIUI, between the tuning procedure and the aerial using the wrong aerial to try and tune to a set of frequencies it wasn't designed for.

Check all connections. Check SDR USB into Pi is not strained...

kevkdg

Re: New ATOM Ground station SDR Detection Issues
« Reply #4 on: December 27, 2020, 09:57:48 pm »
Thanks, will check.

kevkdg

Re: New ATOM Ground station SDR Detection Issues
« Reply #5 on: January 02, 2021, 03:41:00 pm »
Hello,

It seems the updated ATOM software version 20201230 has resolved the RTLSDR USB issues I was having.  Early days but fingers crossed.

According to Keith this SW release included a bug fix where a buffer was being overwritten to make it seem like the RTLSDR was losing its value.

1. I am just wondering, is there a way to see the USB’s detected, the USB Port they are plugged into, and the SDR assignment (OGN/FLARM or 1090) as you do when you first run config but without running the config as this shuts down the services.  For example:

Found 2 SDR's:                                                                                                                                                                                                     
   USB Port Top Left    : SDR detected  ID=1  currently allocated to OGN/FLARM reception on 868Mhz
   USB Port Bottom Left : no SDR detected                                                                                                                                                                         
   USB Port Top Right   : no SDR detected                                                                                                                                                                         
   USB Port Bottom Right: SDR detected  ID=0  currently allocated to ADS-B reception on 1090Mhz
One SDR is currently configured for OGN and the other is configured for ADS-B reception. 

Or can you run 'config', 'ctrl+c' out of it, then run just a command to restart services?

2. On the grid view, for OGN traffic you can see ‘l’ or ‘r’, is it possible to add a column to display the receiving station for ‘r’ OGN signals.  You can see this on OGN Viewer as it flicks between the receiving stations when you click on the Glider?

3. Out of interesting, for ADSB, sometimes you see an uppercase ‘A’ and sometimes a lowercase ‘a’ in the grid view, what’s the difference?

For example:
---al
---Al

4. When you run 'config' on the new SW release 20201230, more options appear:

Do you want to change the ADSB Antenna Gain value () [y/N]: N                                                                                                                                                     
Do you want to change the FLARM Antenna Gain value () [y/N]: N                                                                                                                                                     
Do you want to change the PAW Antenna Gain value () [y/N]: N

These aren't documented on the buidling an ATOM Ground Station PDF so am not clear when you might need to answer 'Y'.

Regards

Kevin

exfirepro

Re: New ATOM Ground station SDR Detection Issues
« Reply #6 on: January 03, 2021, 01:05:15 am »
Hi Kevin,

Sorry to come late to this thread. I have been monitoring it closely, but didn’t like to comment as you had said you were already dealing with Keith/Chris/Lee. Now that a resolution to the problem has been achieved, however, I feel that comment is now appropriate.

Firstly, I’m very glad to hear that the latest 20201230 firmware has resolved the issue with the naming of your SDRs. I had noticed a couple of similar glitches myself during some recent setup tests, though they were nowhere near as serious or persistent as those you were reporting and in my case were easily resolved, so I understand your concern. What I am concerned about, however, especially now that Lee has resolved the issue, is why you still feel the need to ‘tweak the system’ by introducing options so that you can check the USB setup, when this can already be safely and effectively done simply by re-running the config? IMO the more additional ‘options’ we introduce, the greater the risk of mistakes being made by inexperienced users and we should therefore discourage such ‘alternatives’ unless absolutely necessary.

As you are obviously aware, stopping the services is necessary prior to making any changes. Many early users fell foul af this and other issues when trying to establish and configure their stations and simply couldn’t manage to complete the setup. With the significant improvements Lee has introduced over the years, users no longer have to go through the exhaustive process of setting up the stations from scratch and need only a very basic set of instructions and almost no knowledge of Linux. Lee has even simplified the more regularly needed commands so that we no longer need to change directories or run extended configure scripts. Should it be necessary to reconfigure the station, we can now simply log in to the Pi and type config [enter] at the prompt. This stops the services, checks and reports the USB status, and if you don’t need to make any changes it’s simply a case of answering ‘No’ to each question to maintain the status quo. MUCH easier than it used to be. OK it also reruns the GSM scan, but that’s no particular hardship - and before it was automated was probably the major cause of failure to complete the setup and subsequent poor quality operation.

Since we first started the OGN-R project, all of us in the Development Team have maximised our efforts towards simplifying and standardising the setup process to ensure that (as far as possible) all stations on the network are configured to exactly the same standard, regularly automatically updated and operating in exactly the same manner. Preventing unauthorised or inappropriate modification or ‘tinkering’ is essential to this process. This makes things infinitely simpler both for ‘non-techie’ installers and for those of us who have to support them, makes fault finding easier and minimises the potential for errors or incompatibilities to be introduced.

Perhaps more importantly, it also detracts from the opportunity for others to levy criticism that the network fails to achieve an acceptable common standard and has been ‘cobbled together by amateurs’. This is becoming ever more increasingly important in the light of the polarised opinions expressed on the various forums and elsewhere and in the areas and at the levels at which we are now striving to operate.

I hope you can understand my reasons for these comments, they are intended as an explanation, not a criticism.

Best Regards

Peter



Ian Melville

Re: New ATOM Ground station SDR Detection Issues
« Reply #7 on: January 03, 2021, 07:25:32 am »
Quote
Should it be necessary to reconfigure the station, we can now simply log in to the Pi and type config [enter] at the prompt.

That is not reflected in the current instructions.

exfirepro

Re: New ATOM Ground station SDR Detection Issues
« Reply #8 on: January 03, 2021, 08:31:37 am »
Hi Ian,

Yes, I appreciate that - nor are the new antenna gain questions reported in Kevin’s latest post.

Unfortunately it’s a case of rapid development to address issues or introduce improvements as they arise, with the instructions playing ‘catch-up’, rather than waiting for the instructions to be rewritten before introducing the fix or improvement.

I have to say, I wasn’t aware of the antenna gain additions to the config myself until I read Kevin’s  post and don’t yet fully understand the reason for them, so won’t speculate here. In the absence of any instruction to the contrary, however, I suggest simply reply ‘n’ (no) and accept the defaults. I will make some enquiries and let you know what I find out.

Are you having any more luck with your Pi3 setup yet?

Best Regards

Peter


exfirepro

Re: New ATOM Ground station SDR Detection Issues
« Reply #9 on: January 03, 2021, 10:00:42 am »
Kevin,

I meant to comment (positively) on your points 2 to 4, from yesterday’s post (which in general I agree with and would support) but simply ran out of steam last night due to the lateness of the hour (for which I apologise).

When I come across unannounced and undocumented changes to setups or displays (which happens fairly often when testing beta software/firmware) I echo your frustration. I have raised this with Lee and the rest of the Team on several occasions. It is certainly most frustrating to be presented with new installation or configuration steps or ‘coded’ display terminology with no information or explanation as to what they mean or what we are expected to do with them, though I fully understand why this happens and have tried to explain the reasons in my reply to Ian.

You have obviously worked out (as did I) that ‘l’ and ‘r’ in the Status Column indicate whether the traffic is being received by the ‘local’ receiver or ‘relayed’ from another nearby station via the GRID network respectively and whilst I don’t know the definitive answer, I would suspect that ‘a’ versus ‘A’ may be to differentiate between DF-17 (true ADSB) and DF-18 (CAP 1391) signals, though I could be WAY off the mark here. Hopefully Lee will confirm or advise otherwise.

Good idea about a separate column to indicate the receiving station for ‘r’ signals BTW.

We are as a group definitely NOT against change - where this represents improvement. This is in fact the ethos of PilotAware. Where necessary or desirable, change can be implemented extremely quickly. We are just against over-complicating the system and introducing unnecessary options which can lead to confusion and mistakes - especially for ‘non-technical’ users. To this end ALL suggestions are considered. It’s just that with such a small team and so much happening at pace, improvements have to be prioritised and fixes and development can quickly outstrip the team’s ability to keep the paperwork ‘up to the minute’. We need to work harder on this.

Hopefully Lee will come back with definitive answers if I have got any of this wrong.

Best Regards

Peter
« Last Edit: January 03, 2021, 11:14:30 am by exfirepro »

Ian Melville

Re: New ATOM Ground station SDR Detection Issues
« Reply #10 on: January 03, 2021, 10:26:15 am »

Are you having any more luck with your Pi3 setup yet?

Thanks Peter for the info.

The Pi I was using has a dead Wifi module. I should have known there was a reason it was in a box on the shelf and not in use.  Got a feeling it was originally in a PAW, but withdrawn. An own goal  ::) New one on order.

kevkdg

Re: New ATOM Ground station SDR Detection Issues
« Reply #11 on: January 03, 2021, 11:24:40 am »
Thanks Ian for your comments :-)

I agree, if re-running 'config' periodically is now stable (previously if I ran it I would get varying results wrt SDR detection and assignment), then you're right that a separate report is not required.  I assume that the GSM tuning process is related to the Flarm, and re-running this via config is not a problem.... having said that, I notice each time it runs, it gives slightly different tuning results, even if run in quick succession.

The reason I wanted to periodically check is due to the recent issues which have now been reported as fixed in the new SW release, but which I wanted to monitor for a while.  I believe I was running previously for a period (on previous SW version) where the 1090 RTLSDR was assigned to OGN/FLARM and therefore believe it was affecting (very reduced) the range Flarm signals were being received locally before being relayed from a station much further away.  This makes sense as it was using the 1090 antenna which is not tuned for 868.

Incidentally, I noticed that if I only had the 1090 RTLSDR plugged in, config would auto assign it to OGN/FLARM and the option to allowing you to amend this assignment did not appear.  Not sure if this is/was another bug, or whether this still is the case in the new SW release.  This could affect users only connecting a 1090 antenna, maybe for testing purposes.

With regards to instructions, the "Upgrading an OGN Station" PDF is quite out of date compared to the "Building an ATOM Station".  So, either though I was upgrading, I used the latter "Building an ATOM Station" instructions for the software config side of things.

Incidentally, why in Grid view do registrations not always display, yet in radar view they are there for the same aircraft?

exfirepro

Re: New ATOM Ground station SDR Detection Issues
« Reply #12 on: January 03, 2021, 12:20:16 pm »
Hi Again Kevin,


I agree, if re-running 'config' periodically is now stable (previously if I ran it I would get varying results wrt SDR detection and assignment), then you're right that a separate report is not required.  I assume that the GSM tuning process is related to the Flarm, and re-running this via config is not a problem.... having said that, I notice each time it runs, it gives slightly different tuning results, even if run in quick succession.

The reason I wanted to periodically check is due to the recent issues which have now been reported as fixed in the new SW release, but which I wanted to monitor for a while.  I believe I was running previously for a period (on previous SW version) where the 1090 RTLSDR was assigned to OGN/FLARM and therefore believe it was affecting (very reduced) the range Flarm signals were being received locally before being relayed from a station much further away.  This makes sense as it was using the 1090 antenna which is not tuned for 868.

All understood. Thanks for the clarification.

Quote
Incidentally, I noticed that if I only had the 1090 RTLSDR plugged in, config would auto assign it to OGN/FLARM and the option to allowing you to amend this assignment did not appear.  Not sure if this is/was another bug, or whether this still is the case in the new SW release.  This could affect users only connecting a 1090 antenna, maybe for testing purposes.

The software is deliberately configured to automatically configure the 1st (or only) SDR for Flarm Reception - as collecting and rebroadcasting Flarm Positions was the primary reason for extending OGN to OGN-R and Flarm Reception is technically more complicated (see below). In the early days OGN-R didn't do MLAT or data uplinks. 1090 MLAT and data uplinks are a much later addition, so setup of 1090 only takes place where a second SDR is fitted.

Quote
With regards to instructions, the "Upgrading an OGN Station" PDF is quite out of date compared to the "Building an ATOM Station".  So, either though I was upgrading, I used the latter "Building an ATOM Station" instructions for the software config side of things.

OK on this - I agree the content of these documents does need to be looked at again and any anomalies or inconsistencies addressed.

Quote
Incidentally, why in Grid view do registrations not always display, yet in radar view they are there for the same aircraft?

Not sure, I'd need to check with Lee.

Quote
I assume that the GSM tuning process is related to the Flarm, and re-running this via config is not a problem.... having said that, I notice each time it runs, it gives slightly different tuning results, even if run in quick succession.

Correct. The GSM Scan is designed to check for frequency offset in the Flarm Receive SDR and set an accurate centre frequency. This is very important as Flarm actually 'frequency hops' between two frequencies spaced slightly apart and also runs at very low power. 'Cheaper' dongles can have a fair degree of inaccuracy and frequency drift, so determining the offset and setting the centre frequency accurately for each specific dongle is extremely important. The GSM scan process tests to determine the frequency offset of your specific dongle by using nearby GSM signals - which is why the results can vary from test to test, though usually within acceptable limits. (It's not so much what it is reporting but what the software then does with this information that counts). In point of fact, Frequency Offset is usually very near zero when we use SDRs with Temperature Controlled Crystal Oscillators (TCXO) like the ones you will have been supplied with if you got them from Keith - but the GSM Scan is still the best way to ensure an effective setup and also allows us to determine the optimum gain setting for the SDR. It isn't needed (or done) for the 1090 MHz Rx SDR (much broader bandwidth and higher power signals) and the P3i frequency is set by the Bridge.

Hope this helps clarify things a bit further.

Best Regards

Peter

steveu

Re: New ATOM Ground station SDR Detection Issues
« Reply #13 on: January 03, 2021, 03:53:50 pm »

Unfortunately it’s a case of rapid development to address issues or introduce improvements as they arise, with the instructions playing ‘catch-up’, rather than waiting for the instructions to be rewritten before introducing the fix or improvement.

Without wanting to make myself unpopular or upset anyone, with software it makes sense for the auditing process to help users.

There is a reason why software gets revised, and it should be in the revision notes. Whilst I'm not suggesting that a release that fixes a problem should be delayed for the instructions to be updated, it's about an hour a month for a volunteer to just look through and update the instructions, get them proof read then issue a PDF with a revision version attached to it.

If we keep the instructions up to date (or close to it) then it might lead to less support queries on the forum.

Even if you have a Google or Dropbox document that one liners get dropped whilst development is going and when problems are solved, it's something to beat into a form to update the instructions with. Otherwise, there may be a risk of frustration on the part of those who follow the instructions, and don't know to come here when stuck. They then provide anonymous accounts of how things don't work elsewhere...




kevkdg

Re: New ATOM Ground station SDR Detection Issues
« Reply #14 on: January 03, 2021, 04:59:00 pm »
Hi Peter,

Regarding my earlier point:
Quote
Incidentally, why in Grid view do registrations not always display, yet in radar view they are there for the same aircraft?

When I say radar view, I meant the OGN fed www.gliderradar.com radar.  This is now fed by our ATOM station and displayed the aircraft registrations for the OGN traffic being received locally by UKRUF, yet the UKRUF Grid and UKRUF VRS did NOT display the registrations for 2 of the Flarm gliders but incidentally did for the Flarm equipped tug (G-OYGC which only has Flarm, no Mode S or ADSB).  I wonder if they resolve the Hex/ICAO Id for the aircraft against their own local database for the reg?  Please see the attached screenshots:

Keith supplied us with one RTLSDR which we are using for the 1090 antenna.  We already had a FLARM antenna and RTLSDR which we used to feed the OGN network for a couple of years before upgrading (the RTLSDR is housed directly beneath the Flarm Antenna in a weatherproof box and a 4m to 5m USB cable runs externally to the Raspberry Pi which is housed inside).  These are the figures we're getting post the GSM tuning process (I've no idea what each one means or whether it is good or bad):

Station SDR PPM is             : 67                                                                                                                                                                               
Station SDR Gain is            : 40                                                                                                                                                                               
Station SDR Freq Centr is      : 922.800

Both RTLSDR USB's appear to be listed as the same type:

pi@ognpaw:~ $ lsusb
Bus 001 Device 005: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T                                                                                                                                         
Bus 001 Device 004: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T                                                                                                                                         

Finally, as you can see from the attachments, this morning we had some local Flarm signals picked up from 3 aircraft, yet the UKRUF Flarm report is not reflecting these in the "over last 12 hours"
 
Traffic rates [visible/all]   
Aircrafts received over last 12 hours   0/0

Kind Regards

Kevin