Radio interference when using Raspberry+UPiS in the car

Post here your applications done based on UPiS
Share your ideas about new possible applications

Radio interference when using Raspberry+UPiS in the car

Postby juiba » Sat Aug 23, 2014 1:25 pm

Hello,

The following is not firmware related issue, but rather than UPiS or maybe even Raspberry related thing. (Firmware has been working fine except couple of instances when Raspberry has been powered off while power is still supplied, but this might relate to my scripts as well - I will investigate this in near future and will come back if issue is UPiS related.)

The issue which I'm having at the moment is the radio interference when using system in the car. I disabled all USB modules (wifi and GPS receiver), but even then every time I supply power to Raspberry+UPiS there is significant interference in the car radio. When UPiS runs on battery with no power supplied from cigarette lighter there is no interference. I have not yet tested if interference is in place if I use only Raspberry without UPiS, but I will do that when I have time.

Have you guys noticed anything like that and if yes how did you get rid of this?

BR, Jussi
juiba
 
Posts: 24
Joined: Thu Jul 10, 2014 10:45 pm

Re: Radio interference when using Raspberry+UPiS in the car

Postby Pimaster » Sat Aug 23, 2014 5:49 pm

Hello,
Hi,
My answer is in the text as usual.


The following is not firmware related issue, but rather than UPiS or maybe even Raspberry related thing. (Firmware has been working fine except couple of instances when Raspberry has been powered off while power is still supplied, but this might relate to my scripts as well - I will investigate this in near future and will come back if issue is UPiS related.)

The new firmware update is still beta and we are working on it to cover the last remaining weak points.
Basically we changed completely the initial firmware design, so it takes time to adopt it to complete new reality, following our customers requests.

The issue which I'm having at the moment is the radio interference when using system in the car.
OK

I disabled all USB modules (wifi and GPS receiver), but even then every time I supply power to Raspberry+UPiS there is significant interference in the car radio.
OK

When UPiS runs on battery with no power supplied from cigarette lighter there is no interference.
QUESTION: What voltage and what powering input you are using for the UPiS powering ?
OK
On my opinion there are two suspicious noise sources:
1. The EPR Switching power converter
2. The cigarette lighter


I have not yet tested if interference is in place if I use only Raspberry without UPiS, but I will do that when I have time.

Have you guys noticed anything like that and if yes how did you get rid of this?

Please answer to my question above and we will fix the problem you have.

Warmest Regards
Pi Master

BR, Jussi
Warmest Regards
PiM
---
Designing with Mentor Graphics PADS - www.pads.com
Please read and follow the PiForum rules
http://www.forum.pimodules.com/viewtopic.php?f=13&t=196
---
Pimaster
Site Admin
 
Posts: 1593
Joined: Fri Sep 14, 2012 7:50 am

Re: Radio interference when using Raspberry+UPiS in the car

Postby juiba » Sun Aug 24, 2014 10:33 am

Cigarette lighter USB adapter is providing 5V output. I tested with both UPiS and Raspberry input and static noise was present each time. Then I also tested using separate device (small USB charged battery) with my adapter and noise was present also then.

I guess this issue is not UPiS or Raspberry related, but possibly car or cigarette lighter USB adapter. I will test with or other adapters next. Unfortunately it's always challenge to find adapter that provides enough current; my experience is that cheap China adapters provide less than 1A which seems not to be enough for charging. :(

BR, Jussi
juiba
 
Posts: 24
Joined: Thu Jul 10, 2014 10:45 pm

Re: Radio interference when using Raspberry+UPiS in the car

Postby Pimaster » Sun Aug 24, 2014 2:26 pm

Hi,

Cigarette lighter USB adapter is providing 5V output.
If you are powering the UPiS with 5V (to their micro USB) there is no witching power converter working on that time.
So, therefore there is no nose source on the UPiS


I tested with both UPiS and Raspberry input and static noise was present each time. Then I also tested using separate device (small USB charged battery) with my adapter and noise was present also then.

It is fact that, during cable powering of the UPiS, the switching power converter of the 5V, is in stand by mode, in order to start-up as fact as possible, but it is not a noise source at all.

I guess this issue is not UPiS or Raspberry related,
I Agree

but possibly car or cigarette lighter USB adapter.
This should be a source of this nose.

I will test with or other adapters next. Unfortunately it's always challenge to find adapter that provides enough current; my experience is that cheap China adapters provide less than 1A which seems not to be enough for charging. :(
Agree, and if you are drawing more current from a device that has been designed with possible lowest cost, you are always, running near the technical maximum, so on a switching converter can cause noise generation.

Warmest Regards
Pi Master


BR, Jussi
Warmest Regards
PiM
---
Designing with Mentor Graphics PADS - www.pads.com
Please read and follow the PiForum rules
http://www.forum.pimodules.com/viewtopic.php?f=13&t=196
---
Pimaster
Site Admin
 
Posts: 1593
Joined: Fri Sep 14, 2012 7:50 am

Re: Radio interference when using Raspberry+UPiS in the car

Postby juiba » Thu Aug 28, 2014 6:55 am

Hi again,

As this most likely is not UPiS related problem so this forum might not be the correct place to continue this discussion. However, as it seems that many users use UPiS+Raspberry combination in their car this might still contain some valuable info for them, so I will post my newest thought related to this issue.

I have now been able to isolate this problem a bit. See below.

1) My car contains three different cigarette lighter outputs (two in the front and one in the trunk). I am not able to reproduce problem when using outputs inside the car. The problem is related only to output in the trunk. (Unfortunately the trunk is the best place to store Raspberry+UPiS, so I would not want to change the location.)
2) I have tested two different USB adapters that can provide 2,1 A current: Belkin and Fuj:tech. Both of them produce the radio interference with any of the tested devices (Raspberry+UPiS, external USB battery, iPhone 5).
3) When I'm using no-name Chinese adapter that can provide only 1 A current, I cannot reproduce the issue. This adapter charges both external USB battery and iPhone correctly, but unfortunately the current seems not to be enough for UPiS - it is not charging.

I have couple of ideas how I could continue from here. First one is to buy a brand name (such as Apple, Nokia, Tomtom etc.) USB adapter that can provide enough current for UPiS and test if the problem would continue also then - to make sure if problem is adapter or car related. Second one is to try to ground trunk adapter more better as the problem is related only to that one (and not to outputs inside the cabinet).

I will let you know if I'm able to fix this problem, but your thoughts are also highly appreciated.

BR, Jussi
juiba
 
Posts: 24
Joined: Thu Jul 10, 2014 10:45 pm

Re: Radio interference when using Raspberry+UPiS in the car

Postby juiba » Fri Sep 12, 2014 9:35 pm

Just for the record, I was able to resolve this problem. I bought a new adapter (Insmat) which has micro-usb cable integrated and is providing only 1,2A current instead of 2,1A (the previous ones). If there is now any radio interference it is at least so minimal that it doesn't bother me anymore. So, that's good news. :)

One question came up during this process: When I tested these different adapters just to find solution to this problem I found out that UPiS will not charge if current is too low. I'm not quite sure, but it seems like UPiS needs about 1A currency all the time in every case in order to charge the battery. This seems strange as amount of currency that Raspberry is using doesn't seem to make change. In addition if the max charging currency is about 300 mA this doesn't make sense to me. Or is there something that I'm missing here?

BR, Jussi
juiba
 
Posts: 24
Joined: Thu Jul 10, 2014 10:45 pm

Re: Radio interference when using Raspberry+UPiS in the car

Postby Pimaster » Sat Sep 13, 2014 5:05 am

juiba wrote:Just for the record, I was able to resolve this problem. I bought a new adapter (Insmat) which has micro-usb cable integrated and is providing only 1,2A current instead of 2,1A (the previous ones). If there is now any radio interference it is at least so minimal that it doesn't bother me anymore. So, that's good news. :)


Yes, that is good news !

juiba wrote:One question came up during this process: When I tested these different adapters just to find solution to this problem I found out that UPiS will not charge if current is too low. I'm not quite sure, but it seems like UPiS needs about 1A currency all the time in every case in order to charge the battery. This seems strange as amount of currency that Raspberry is using doesn't seem to make change. In addition if the max charging currency is about 300 mA this doesn't make sense to me. Or is there something that I'm missing here?

BR, Jussi


Yes, that is right, if current is not enough, charger is stopping in order to safe power for the RPi. It is one of the "intelligent" features UPiS has.

BR Pi Master
Warmest Regards
PiM
---
Designing with Mentor Graphics PADS - www.pads.com
Please read and follow the PiForum rules
http://www.forum.pimodules.com/viewtopic.php?f=13&t=196
---
Pimaster
Site Admin
 
Posts: 1593
Joined: Fri Sep 14, 2012 7:50 am


Return to UPiS Users Application

Who is online

Users browsing this forum: No registered users and 1 guest

cron