yashsingh1/xdaforums huggingface dataset:
[Android Head-Units] ab1702:
I must say I agree with what you’re saying.

I used to have a unit I got from erisin which I think was a KGL px5 android 6 and using a window sticker antenna. Signal wasn’t great but when I increased the brightness of the screen on the unit it lost the signal for the dab( must be some shielding/noise issue from the unit). Also if I pulled the headunit out of the dash that sometimes also increased the signal for dab. I have the dab receiver in the glove box at the moment but I remember previously having it in different places where it was once behind the unit and the signal was terrible. Also I once opened up one of the dab units that I received from erisin and there was no shielding inside it at all.

Anyway I returned the unit in the end and got a GS px5 from xtrons with Android 8 and low and behold I had the same problem.

In the end I bought a roof mount fm/am/dab antenna from eBay for about £25 and drilled a hole in the roof of the car and it’s been the best thing I ever did. I have a ford custom work van with factory dab with a big antenna on the roof and the dab(using this app) coverage in the car is just as good as the factory fit dab in the van. The signal must now be that strong with the roof mount antenna that the noise from the unit isn’t enough to affect it anymore as signal is always good now.
[Android Head-Units] mcwieger:
[MENTION=7838245]realzoulou[/MENTION] can you add a link to the post where manually adding station logo's is explained to your starting topic? Searching the current 242 forum pages for this is not something that can be asked from end-users, since a search itself is giving 12 pages of search results...:)
[Android Head-Units] DrRobin:
I did some more digging:

USB 3.0 generates noise all the way up the spectrum and especially causes problems with WiFi (2.45GHz) as USB 3.0 operates in this band, it is hard to filter. See the following link, still lots of noise at DAB (200-250MHz).

https://usb.org/sites/default/files/327216.pdf

USB 2.0 isn't much better, since it runs at 480mb/s the fundamental is 240MHz, not far from the DAB frequencies (in the UK) and as a result causes interference, unless it is surpressed, see the following:

https://www.murata.com/en-eu/products/emc/emifil/techdoc/automotive1/sgn/main1

Without supression, USB 2.0 actually fails the emissions part of CE marking, that is how bad it is.

I can't tell from the specs which USB it has, I think it is USB 2.0, but that is still a potential problem for DAB.

It looks like the solution is a Common Mode choke, I have some of these so will try them on the USB and coax to see if it helps. I will also add a screen and decent earth at the dongle.
[Android Head-Units] typos1:
It is USB2.0.
[Android Head-Units] realzoulou:
Maybe it is more useful if someone tells me what information is missing on the screen in the app. I tried my best, but seems that I did no good job...

EDIT: Added a picture of how this screen mentioned above currently looks like (v1.7.75)
[Android Head-Units] ZeroZorro:
In the app itself, when you go to Settings>Station Logo's there is a tiny arrow on the bottom that can be ticked. Maybe you have to scroll down to find it even if it looks like the page is already 'ended'. The arrow will open a alinea with text explaining how to get those logos and where to put them to be found by the app....

Verstuurd vanaf mijn Z2_PRO met Tapatalk
[Android Head-Units] DrRobin:
DAB noise solved

I have got to the bottom of the noise problem.

At my test location (DAB) 4 bars on a good head unit, no or 1 bar on the problem head unit, I made measurements with an SDR tuned to 220MHz with 10MHz bandwidth, this covers our national and local DAB frequencies.

The noise floor measured near the head unit (Xtrons TA709IPL) with it switched off is -125dBm. The DAB signal is -105dBm.

With only the head unit powered, the noise jumps to about -100dBm and the signal is completely lost.

If I leave the Xtrons on but with the screen blanked the noise drops to -115dBm. There doesn’t appear to be any noise from the USB.

If I move my SDR and antenna away from the head unit, but still in the car I can get the noise down to -120dBm. So it is the the head unit and most specifically the display.

I reckon the solution is to get a screened usb extension cable with common mode choke and put the DAB dongle in the boot with a good local earth connection and screen the case (I have some copper tape used for a slug barrier which is an excellent screen). Then an external antenna as far from the head unit as possible, which is also on the boot as my car is a soft top. A shark fin would be okay on most cars, just cut the wire.

I will be speaking to Xtrons but don’t suppose I will get anywhere.
[Android Head-Units] realzoulou:
Wow I am impressed by your measurements. Thanks a lot.

This confirms the observation of some users here that the signal drops out, when the display is on.

EDIT: added a picture to #2422 to show the instructions regarding manual logo import
[Android Head-Units] Duvel999:
Yes, found this tutorial

DAB Antenna Installation - http://bbs.xtrons.com/

http://bbs.xtrons.com/viewtopic.php...ang=nl_NL&fromApp=true#p58&statusBarHeight=80
[Android Head-Units] ab1702:
Just as I thought from my previous experience.

What headunit is it you’re using? The trouble I had it with was a KGL px5 and a GS px5.

Before these units I had an android 4.4 unit, didn’t know about mcu’s or anything then so don’t know what kind of unit it was but I had a windscreen antenna with that one and the signal was a lot better than when I tried to do the same thing on the px5 units so this problem must only be with certain units.

These common mode chokes that you refer to are they the same as a ferrite bead? I have put some of these on my unit if so. I think I put one on the usb for the dab, I put one on each power cable and I put some on the speaker outputs as I had alternator whine and it considerably improved the sound and got rid of most of the whine. I tried earthing things before but it made no difference as everything is already earthed one way or another. All the noise/interference always appears to be from the unit itself.
[Android Head-Units] DrRobin:
Hi,

The head unit that makes all of the noise is an Xtrons TA709IPL. I do have another Xtrons HU (an Octa Core Android 8), that seems to be okay.

A common mode choke comes in two basic forms one, is a ferrite core and the other is a transformer, they do a similar job but are to guard against different things.

A ferrite core is used to clamp over a multi-core cable, or better yet wrap the cable through several times, this attenuates noise in all of the cores of the cable and especially effective against noise in the screen (if it has one). A ferrite bead is similar, but is usually much smaller (just big enough to fit over a single core) and is used to filter noise on a power line (+12V DC).

A common mode transformer, is used for data or signal lines, it only filters common mode noise from differential signal lines/pairs. USB ports usually use a transformer on the data lines and a ferrite bead on the +5v line.

The problem with my Xtrons unit seems to be noise in the [coax] screen or directly in to the [un-screened] DAB dongle so moving the dongle away from the HU, screening it and use a ferrite core on the USB and coax should fix the problem as I doubt I am going to be able to stop the noise coming out through the display of the HU.
[Android Head-Units] mcwieger:
Apologies, indeed this is a good manual. I did not see the triangle that expands this text on my screen. Got it now.
[Android Head-Units] realzoulou:
Yeah, I need to fix these layout issues...
[Android Head-Units] hapaman:
What could be the reason to have a 2-3 second stutter when changing station in omri modus? I'm dab-z user since a while and it came with the upgrade and omri support. If I disable the omri modus, there's no stutter.
[Android Head-Units] VBA_Dev:
Logcat attached that hopefully shows something from the laggy settings pages.
[Android Head-Units] DrRobin:
After another weekend of testing I now know that it is the backlight on the display which is causing the noise at 220MHz. If I dim the display the noise reduces and it goes altogether if I turn the display off. It is worst at full brightness. I assume it is the LED backlight which is noisy. This isn't very good, it means without special measures you cannot use this head unit with a DAB adapter.

My DAB dongle is now wrapped in copper tape, in the boot, earthed and fed with a 5m USB cable with ferrites both ends. I have also gone for an external mag mount antenna. DAB reception is now much improved, nearly as good as my other head unit.
[Android Head-Units] ba55bar:
I found an adapter on amazon for my standard car aerial and it works just as well as the window one. Highly recommended it so you get a cleaner look and is obviously much easier to install
[Android Head-Units] realzoulou:
A recommendation without a link where to get it from, or what the name of the adapter is, is quite ... hmm... sub-optimal
[Android Head-Units] Duvel999:
Where's the link:laugh:
[Android Head-Units] ba55bar:
Can't post links when you have less than 10 posts :p

If you search amazon for 'Eightwood dab aeriel splitter' you will find them. They come with different connectors so just need to work out which one you've got
[Android Head-Units] HaTeNL:
How is the antenna working for you? It's really bad here.. Maybe the problem is the led lights I just read about

Edit: nvm, you are not using it..
[Android Head-Units] Flemischguy:
Hi Typos1, sorry for the late reaction, the led lights are original on te car and don't causes the interference with the DAB+ receiver even if they are shielded. The problem in this case, is the radio screen that causes electromagnetic interference noise with the DAB+ receiver. The DAB signals are quite sensitive for EMI noise, a German guy on a Xtrons/ibus group on FB, try to find a solution to block the EMI noise but it ain't an easy task. The brands who build those radio's, has to shielded those radio screens to eliminate or reduce the EMI disturbance.
[Android Head-Units] typos1:
Yes, I think I read a later p[ost that the problem is the screen, at least for some units. Maybe you can shield that somehow ?
[Android Head-Units] Flemischguy:
Shielding the screen on the unit it self is quite hard i think, because it is so close to the components. I was more thinking of separating the radio from the screen, a sort of a hide away unit style like they did in the early days like my old clarion vrx 928 rvd radio.
[Android Head-Units] typos1:
I ve taken units apart in the past many times, so I ve seen inside a few and I really dont think it would be that difficult, but funnily enough, I m modifying my unit and placing the screen higher up the dash. :)
[Android Head-Units] 1979Damian:
If you do decide to take the steps outlined above, could you please do them one at a time and then test for the results because it may be that just 1 of the "fixes" is the solution and if so it would save others attempting all the fixes when they may not need to.
[Android Head-Units] DrRobin:
The TA709IPL has USB 2.0 ports and they are not causing the issue, it is the display backlight which is causing the issue as reported in later posts.

BTW manufacturer's shouldn't sell units in Europe if the fail EMC, so they have to fit chokes and other noise suppression to interfaces like USB. The radiated emmissions of the TA709IPL might be in spec (I doubt it somehow) and the immunity offered by the un-screen USBDAB02 might also be in spec (again doubt it), so might comply with EMC, but the two don't work together.

I doubt I am going to be able to stop the noise coming out of the display, I have wrapped the DAB dongle in copper tape, put it in the boot and earthed everything. I am also using a home made external 1/4 wave mag mount, this has improved DAB reception to nearly as good as my other car with an older Xtrons unit.
[Android Head-Units] r_james_s:
Hi [MENTION=7838245]realzoulou[/MENTION].

Recently I've been having problems with DAB, and I'm certain it's not the fault of your fantastic app because I see the same behaviour with the stock DAB+ app. However,I wondered whether you might be able to shed some light on the problem at all please?

DAB will play for a short while and then the audio will start the stutter (like signal is poor) until finally it will stop completely, the app closes AND the launcher (FCC and stock) restarts. It will take a minute or two for DAB audio to come back, but when it does the symptoms start all over again. This will happen regardless of actual signal strength, which is very good where I live, stationary or moving.

I suspect the USB DAB adapter is faulty. Is there any way within your app or otherwise I can see what's going wrong?

Many thanks in advance

---------- Post added at 09:38 PM ---------- Previous post was at 09:38 PM ----------

Hi [MENTION=7838245]realzoulou[/MENTION].

Recently I've been having problems with DAB, and I'm certain it's not the fault of your fantastic app because I see the same behaviour with the stock DAB+ app. However,I wondered whether you might be able to shed some light on the problem at all please?

DAB will play for a short while and then the audio will start the stutter (like signal is poor) until finally it will stop completely, the app closes AND the launcher (FCC and stock) restarts. It will take a minute or two for DAB audio to come back, but when it does the symptoms start all over again. This will happen regardless of actual signal strength, which is very good where I live, stationary or moving.

I suspect the USB DAB adapter is faulty. Is there any way within your app or otherwise I can see what's going wrong?

Many thanks in advance
[Android Head-Units] realzoulou:
Create a logcat via Settings->Info after this happened. I understand you have a minute before it crashes again, so this should be enough time. If your unit is rooted, then choose to create a system-wide logcat.

Then send this via email to yourself and attach it here.
[Android Head-Units] r_james_s:
logcat

Not sure if the system is rooted... I haven't done so myself.

Logcat created before app crash. Nothing stands out to me (I don't know what any of it means really! :laugh:). File attached.

Thank you!
[Android Head-Units] r_james_s:
This one is after a crash. Not sure if it's any different? The log file looks quite different... I still can't determine if it's telling me there's something wrong!

There is now no audio from DAB after the first crash. It will probably come back after the system has rebooted, but the problem seems to have worsened.

I also sent an Android system app crash report when it crashed, which hopefully you will receive via email.
[Android Head-Units] realzoulou:
[MENTION=4977567]r_james_s[/MENTION] The logs really don't tell much. It is not even visible that the app crashes. The only thing looking really strange is that the Garbage Collector quite often kicks in and stalls the app for several 100ms up to half a second quite often.

You are using OMRI mode. Have you tried with OMRI disabled in Settings->General ? Note: You will need to run a new station scan then.
[Android Head-Units] r_james_s:
I don't recall enabling OMRI mode, but I switched it off and the problem has gone away! DAB is working properly without stalling again - thank you!

What is OMRI and what's the reason for the option in the app?
[Android Head-Units] ale_prince:
I have a Rockchip PX5 A53 Head Unit on a Fiat 500X, apart from a few small bugs the app works well, a suggestion for [MENTION=7838245]realzoulou[/MENTION]: it would be fine if you could see the name of the radio station on the top bar so even if you use it another app you know which channel you are tuned to
[Android Head-Units] NogenLunde:
[MENTION=7838245]realzoulou[/MENTION]

Attached zipped mp4 (mp4 not allowed) showing permanently dead stations in OMRI mode (stations 17, 18, 19, 20).
[Android Head-Units] royalhawk2002:
OT: I think I know you....on the italian 500x forum.....

Inviato dal mio SM-N960F utilizzando Tapatalk
[Android Head-Units] oddvarr:
[MENTION=10451415]NogenLunde[/MENTION]

From your username I assume you are norwegian, so am I.

You can PM me your problems and I can check if I get the same problem as you.

It could help realzoulu find solution.
[Android Head-Units] realzoulou:
[MENTION=4977567]r_james_s[/MENTION]

In January with 1.7.72 (see #2324) I activated OMRI as default mode. Not my best decision as I found out quite quickly...

OMRI specific features are:

- Timeshifting

- Title and Artist of current song (if transmitted by the station)

- Better Slideshow support

- Logo download via Internet

- Some users report generally better sound and more stations.

[MENTION=10500133]ale_prince[/MENTION]

To show the station name instead of "DAB-Z" in Android status bar is technically not possible AFAIK

[MENTION=10451415]NogenLunde[/MENTION]

Thanks for the video. Interesting to see that also the bitrate is not detected. I suspect some sub-optimal implementation of the DAB standard in OMRI regarding primary/secondary service components. And there is another difference: For "NRK_P1_More&Ro" OMRI shows SId=F501, but libdab uses SId=F511.

One thing I was missing in your video: What are the station details in libdab mode for "NRK P1 Trondelag"?
[Android Head-Units] ale_prince:
....buy my uconnect!! :laugh::laugh:

thanks anyway [MENTION=7838245]realzoulou[/MENTION]
[Android Head-Units] okij:
[MENTION=7838245]realzoulou[/MENTION]: I also experience issues when flicking stations rapidly.

As a workaround I would suggest a built-in (or adjustable) delay when switching stations in OMRI mode, so that DAB-Z waits e.g. 1 second before the next station change.

That should fix at least one of the known OMRI bugs. What do you think?
[Android Head-Units] oddvarr:
[MENTION=7838245]realzoulou[/MENTION]

I have recently upgraded my PX5 from stock Android 8 to Hal9K Android 9.

Running FCC as launcher

After this I discovered something strange I do not seem to recall was there before i upgraded.

I have made a favourite list containg 18 stations.

When I change station I get a toast notification with prefix "2/18" and then the channels name.

Number 2 is the new stations place in my list and 18 is then total number of stations.

These numbers are things I would like to NOT see.

Are the numbers added by DAB-Z or is it pulled from Android system?

I can not find a way to disable these numbers from notification.

The same apply to music when changing song, Poweramp.

Speedfire-, FCC developer, says these number is NOT generated by FCC. So it must be the app or android system.

I am trying to narrowing down where to ask for some soultion.
[Android Head-Units] realzoulou:
No, this would not help. By rapidly changing stations you only increase the probability of a general issue to occur in a certain time period.
[Android Head-Units] realzoulou:
Not from DAB-Z either. Must be something else.
[Android Head-Units] okij:
OK, I see.

So I suggest a different approach: What about some sort of watchdog which looks if the OMRI decoder has crashed and then restarts it?
[Android Head-Units] NogenLunde:
OMRI and libdab shows the same SId, it's just the very similar names of the stations that is confusing (i.e. "NRK P1 Trondelag" and "NRK P1+ Trondelag" are two different stations).

So the conclusion is that this probably is a bug in OMRI implementation, and nothing we can do? I can test the same stations in a BMW with original DAB+ radio later this month, if that can be of interest.

Regarding the toast "No audio! try with OMRI disabled", I've had a couple of false positives, in relation to switching (or browsing) stations. The other "no sound" bug, where stations randomly can loose audio, still doesn't trigger this toast. I will try to catch that on video next time.
[Android Head-Units] IG_Vasilich:
[MENTION=7838245]realzoulou[/MENTION]

small glitch in latest version: during scan there is a message, that RadioDNS logo won't be downloaded because of missing internet connectivity. So far fine, but i have disabled RadioDNS in settings :) and still got that message.

And additional question: Where RadioDNS logos are saved?
[Android Head-Units] IG_Vasilich:
and some more test results:

installed latest DAB-Z, deleted all stations from hessen ensemble, did an "update rescan", got all stations back, unfortunately with same wrong bitrate 32kbps (instead of 136 or 144 or anything higher that 88 kbps). Note that i have seen proper bitrate in DAb-Z release about ~1.5 months ago, and still se proper bitrate in libdab mode.

P.S. I still have a strong feeling, that the stuttering of such stations is correlated with general CPU load. after closing/killing all possible background processes (like Torque, music player in stop mode, etc.) and with stopped car engine i have listened hr3 several minutes without stuttering. No stuttering when using libdab mode in all scenarios.

P.P.S. Do you know whether OMRI lib goes opensource somewhen? though it has much more features than chinese libdab, it is quite unstable yet (as i often get DAB-Z crashed in OMRI mode - either on fast station switching, or just during listening to stations with DAB-Z in background)...
[Android Head-Units] DrRobin:
TA709IPL Noise sorted

Hi,

I have finally fixed the DAB noise problem on my Xtrons TA709IPL, here is what I did:

1) Moved the DAB dongle to the boot on a 5m USB cable with common mode chokes fitted;

2) Wrapped the DAB dongle in copper tape and added an earth;

3) Fitted an external (DIY) mag mount DAB antenna;

4) Applied copper tape to the TA709IPL case, connecting the case near to the display to the RF connectors on the rear panel;

5) Fitted 3 pieces of copper tape to the radio cradle/tray and connected to the vehicle earth;

6) Ensured a very good connection between the TA709IPL taped case and vehicle earth.

This has killed the noise coming out of the TA709IPL and entering the USBDAB02 dongle. Previously where I would get no signal or 1 bar I now get 4 to 5 bars.

In summary, the Xtrons TA709IPL screen/display or backlight is very noisy at DAB frequencies. Moving the DAB dongle away and through a metal panel helped, but earthing the TA709IPL case also assisted greatly. Looks like Xtrons didn't shield the head unit very well and no shielding at all on the DAB dongles.
[Android Head-Units] typos1:
Cool, well done !

Xtrons did not make your unit, they are just a retailer, they buy units from manufacturers stick their badge on and sell them, your MCU will tell you who made your unit, the letters in it refer to the manufacturer.
[Android Head-Units] realzoulou:
Oh, yes you are right. I mixed the P1 and P1+.

As of now, I cannot modify OMRI. But the plan is still that it will be published as Open Source. No need for test in a BMW.

The toast only comes when you switch to a new station and after 5 sec still the information about the codec (MP2 or AAC) is not available to the my app, but the signal level is at least 2 bars. When audio is lost afterwards it does not trigger a toast. Rapid switching between stations may confuse my hacky algorithm...

Currently in OMRI mode, RadioDNS logo download is ALWAYS happening, irrespective of the setting. The setting only decides whether the RadioDNS logos are used.

But I agree that this is confusing. I'll change it.

In the app cache directory, typically this is /data/user/0/com.zoulou.dab/cache/

My current state of analysis points towards heavy memory allocations of the app, followed by garbage collection by Android, which stalls the app as a whole for several 100ms.

A generally high CPU load at that time due to other apps makes it then audible due to audio drop outs.
[Android Head-Units] VBA_Dev:
:good: Some good changes and bug fixes there. I’ll download the beta tomorrow. :)