stevhorn5
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Sadly, I've given up on RPi

Sat Aug 18, 2012 6:40 pm

After nearly two months of tinkering with it I cannot resolve the problems it causes with my wifi network. In a nutshell, after being powered up for an hour or so, bandwidth on my wifi network completely drops off until it is unusable with any device. It doesn't matter whether the RPi's connected to the wired network, wireless network, or no network. Just being in a powered-on state causes the problem. When I unplug it, my wifi comes back to life. (Perhaps my RPi is faulty.)

I'm quite certain that it's not my router as I have various devices which connect to it without an issue:

4 desktops
4 tablets
5 laptops
1 iPhone
1 Blackberry

My dreams of a cheap media centre are over. (Maybe not, I've ordered the Rikomagic MK802 II :D )

ksangeelee
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Re: Sadly, I've given up on RPi

Sat Aug 18, 2012 7:53 pm

stevhorn5 wrote:After nearly two months of tinkering with it I cannot resolve the problems it causes with my wifi network. In a nutshell, after being powered up for an hour or so, bandwidth on my wifi network completely drops off until it is unusable with any device. It doesn't matter whether the RPi's connected to the wired network, wireless network, or no network. Just being in a powered-on state causes the problem. When I unplug it, my wifi comes back to life. (Perhaps my RPi is faulty.)
...
My dreams of a cheap media centre are over. (Maybe not, I've ordered the Rikomagic MK802 II :D )
You've got a golden opportunity to solve an obscure and intriguing problem - is there no end to the joy this little device brings us? Perhaps it's radiating too much RF for some reason.

Does this happen when nothing but the power supply is connected to the Pi? (no dongles, no Ethernet cable, no HDMI)
Are there any wires (or other metal, such as a case) underneath the Pi?
If the Pi is moved to the other side of the room, or to another room, does the problem go away?
If the Pi is plugged in next to a computer, but away from the router, does this localise the problem?

fredjam
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Re: Sadly, I've given up on RPi

Sun Aug 19, 2012 1:29 am

Its not sad at all. The pi wasn't designed to be a cheap media centre, although it will be used in this
way when the teething problems are sorted out.

You obviously don't have any patience so you should stick to buying finished consumer
products in future. Try the WD TV live, that's a good media centre and it works out of the
box so no unpleasant tinkering around. .

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Re: Sadly, I've given up on RPi

Sun Aug 19, 2012 3:22 am

I suggest the Roku2, pretty much the same HW as the Raspi with some added bells and whistles.

It's a very odd issue though - I'd actually suggest trying to RMA it - it does sound like it may be radiating badly, which I would think is a valid RMA case.
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Jim JKla
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Re: Sadly, I've given up on RPi

Sun Aug 19, 2012 6:32 am

There's a lot of people out there after a RPi I am sure you could move it on at cost. ;)
Noob is not derogatory the noob is just the lower end of the noob--geek spectrum being a noob is just your first step towards being an uber-geek ;)

If you find a solution please post it in the wiki the forum dies too quick

dom
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Re: Sadly, I've given up on RPi

Sun Aug 19, 2012 10:07 am

This exact issue has been reported before and was solved by replacing the HDMI lead. Poor shielding on the HDMI cable can lead to interference.

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Jim JKla
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Re: Sadly, I've given up on RPi

Sun Aug 19, 2012 10:17 am

Is that on the wiki troubleshooting page dom?
Noob is not derogatory the noob is just the lower end of the noob--geek spectrum being a noob is just your first step towards being an uber-geek ;)

If you find a solution please post it in the wiki the forum dies too quick

dom
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Re: Sadly, I've given up on RPi

Sun Aug 19, 2012 10:40 am

Jim JKla wrote:Is that on the wiki troubleshooting page dom?
No, although there is only one report I'm aware of where this was confirmed. I'd prefer to see more of a pattern before this is reported as fact.

tech_monkey
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Re: Sadly, I've given up on RPi

Sun Aug 19, 2012 10:54 am

Is it always after an hour or is it sometimes more or sometimes less. It could be a device gets disconnected when not used for a while, and then tries to reconnect when in use (power saving mode on many laptops and phones etc work like this and some desktops as well). And when this device reconnects it causes a conflict.

Some routers have a limit on the total number of devices that can be connected. This is normally done, by your ISP, to prevent too many people sharing the same internet connection ( the default seems to be either 15 or 16 connections). I would log into your router, and check the log and see what is happening there, and if you can see if you can change the total number of connections. Also there could be an IP conflict, this has caused me no end of problems with my wife's Vista laptop causing problems over the network. Had to give it a static IP address in the settings within Windows, even though I had set it up via the router to always give it the same IP address.
Have you tried unplugging/ disconnecting everything except the PI from the router, does this still work after an hour. If it does then try reconnecting devices one at a time as it my not be the PI causing the problem.
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stevhorn5
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Re: Sadly, I've given up on RPi

Sun Aug 19, 2012 1:16 pm

Thanks for the advice. Maybe I'll tinker some more until my MK802 II shows up. My thoughts are that it's giving off some kind of RF interference. I'll try swapping out the HDMI cable. I haven't tried powering it up without any cables so I'll give it a whirl as well.


fredjam:
I take offence at the statement, "You obviously don't have any patience so you should stick to buying finished consumer products in future." I've been playing around with this almost on a daily basis since June 20, when I received it, so I'm not sure patience is what I lack. I've been in the computer world in one form or another since 1985, IT site manager at my place of employment before I retired, and I've been building my own computers since 1995 and proud to say I haven't bought a retail desktop since that time. None of them run Windows: two are Hackintoshes and two are Linux. This RPi, and the network issues it has caused, are a mystery to me. I can't say I've ever seen anything quite like it.

I'm well qualified to deal with most IT issues, but this one eludes me.

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Jim JKla
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Re: Sadly, I've given up on RPi

Sun Aug 19, 2012 2:07 pm

dom wrote:
Jim JKla wrote:Is that on the wiki troubleshooting page dom?
No, although there is only one report I'm aware of where this was confirmed. I'd prefer to see more of a pattern before this is reported as fact.
Wonder if it is worth putting a refrence in the troubleshooting page with a request for a PM here if it results in a fix? ;)
Noob is not derogatory the noob is just the lower end of the noob--geek spectrum being a noob is just your first step towards being an uber-geek ;)

If you find a solution please post it in the wiki the forum dies too quick

fredjam
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Re: Sadly, I've given up on RPi

Mon Aug 20, 2012 2:03 am

Well you say you have been tinkering since June but what has your tinkering amounted
to. The pi is giving off interference, I think this is true. Have you tried putting it in a metal
box and connecting the metal box to the ground line of the pi.

stevhorn5
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Re: Sadly, I've given up on RPi

Mon Aug 20, 2012 12:11 pm

fredjam wrote:Well you say you have been tinkering since June but what has your tinkering amounted
to. The pi is giving off interference, I think this is true. Have you tried putting it in a metal
box and connecting the metal box to the ground line of the pi.
That's better! Now you're giving some practical advice. I'll give it a try.

Joe Schmoe
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Re: Sadly, I've given up on RPi

Mon Aug 20, 2012 12:16 pm

Heh heh. My little bon mot has been censored.
And some folks need to stop being fanboys and see the forest behind the trees.

(One of the best lines I've seen on this board lately)

stevhorn5
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Re: Sadly, I've given up on RPi

Mon Aug 20, 2012 12:39 pm

Thanks for the feedback tech_monkey.
tech_monkey wrote:Is it always after an hour or is it sometimes more or sometimes less. It could be a device gets disconnected when not used for a while, and then tries to reconnect when in use (power saving mode on many laptops and phones etc work like this and some desktops as well). And when this device reconnects it causes a conflict.
It can be more or less. I've had it run for 3 or 4 hours sometimes before the wifi drops off.
tech_monkey wrote: routers have a limit on the total number of devices that can be connected. This is normally done, by your ISP, to prevent too many people sharing the same internet connection ( the default seems to be either 15 or 16 connections). I would log into your router, and check the log and see what is happening there, and if you can see if you can change the total number of connections. Also there could be an IP conflict, this has caused me no end of problems with my wife's Vista laptop causing problems over the network. Had to give it a static IP address in the settings within Windows, even though I had set it up via the router to always give it the same IP address.
Have you tried unplugging/ disconnecting everything except the PI from the router, does this still work after an hour. If it does then try reconnecting devices one at a time as it my not be the PI causing the problem.
I assign static IPs to all my devices, including the RPi.
tech_monkey wrote:Have you tried unplugging/ disconnecting everything except the PI from the router, does this still work after an hour. If it does then try reconnecting devices one at a time as it my not be the PI causing the problem.
I'm checking this idea out today. I'll report back later.

drgeoff
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Re: Sadly, I've given up on RPi

Mon Aug 20, 2012 5:06 pm

fredjam wrote: Have you tried putting it in a metal box and connecting the metal box to the ground line of the pi.
Unless the ground line of the RPi is well grounded at radio frequencies, connecting it to a metal box could actually make any radiated interference stronger, not weaker.
Quis custodiet ipsos custodes?

stevhorn5
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Re: Sadly, I've given up on RPi

Mon Aug 20, 2012 10:17 pm

Maybe the RPi just doesn't play nice with my D-Link DIR-655.

I setup my old D-Link DIR-615 as an AP (It had stopped serving IP addresses about a year ago and I replaced it with the DIR-655.)

I moved all my wireless devices to the DIR-615 and after 10 hours of use my wifi is still going strong.

I'll see how things play out over the next couple of days and report back.

fredjam
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Re: Sadly, I've given up on RPi

Tue Aug 21, 2012 1:30 am

drgeoff wrote:
fredjam wrote: Have you tried putting it in a metal box and connecting the metal box to the ground line of the pi.
Unless the ground line of the RPi is well grounded at radio frequencies, connecting it to a metal box could actually make any radiated interference stronger, not weaker.
Well yes it could make it worse but that in itself would show something. The Raspberry pi is
a completely unshielded computer board so it probably radiates at many frequencies and
should be kept well away from other wi-fi devices.

I use a logitech wireless keyboard and trackball with my pi and I know that it only has a range
of a few inches. Used with my main computer which is no doubt well shielded it has a range
of several feet.

However the symptoms you describe i.e it only happens after an hour or so are more puzzling,
perhaps your pi is faulty. Perhaps it is the effect of heat build up on the board or in the power
supply. You are the only one who can pin it down. As far as I know you are the only person to
report this fault.

When your network slows down open a terminal on the pi and enter 'tail -f /var/log/messages'
disconnect your keyboard and reconnect it to see if there are any eth0 error messages.
When the network slows down open a terminal and enter 'ping yahoo.com'. .What are the ping
times.

.

stevhorn5
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Re: Sadly, I've given up on RPi [Solved]

Wed Aug 22, 2012 10:57 am

Well, it seems my wifi woes were the result of interference from my (cheap) HDTV. My original setup had my wireless router and RPi within centimetres of my HDTV which was the source of the interference. (Perhaps the cheap speakers in the TV are unshielded.) Once I put some separation between the 3, the problem disappeared.

Thanks to all for the advice.

fredjam
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Re: Sadly, I've given up on RPi

Thu Aug 23, 2012 3:51 am

Glad to hear you have resolved the problem and don't think that the pi
is a complete waste of time any more.

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