WiFi connection always breaks down after a few hours

[UliZappe]

Hi everyone,

I’m fairly new to the Arduino Yún and don’t even know if this is the best place to report this issue, but here we go …

Since starting out with the Yún last October, I’ve never been able to get a stable WiFi connection. Everything works fine for a few hours (something between 5 and 50), and then the connection breaks down (i.e. all network requests to the Yún time out). This has happened in 100% of my trials.

So far, what I could verify is that it’s not:

1. A Bonjour/mDNS issue – trying to connect via IP address fails, too
2. A hardware issue – I have three Yúns bought several weeks apart from different sources, and they all sport exactly the same issue
3. A router issue – I use many WiFi devices apart from the Yúns, and none has any problems. I also took one Yún someplace else with a completely different router, with exactly the same result. (My router is a DrayTek Vigor2750.)

Since I found some at least similar reports on the Arduino-Yún forums, I was hoping that updating to the new OpenWrt-Yún software version would finally fix this issue, but it’s completely unchanged.

What I don’t get is that clearly, built-in WiFi is one of the main points why you would use an Arduino-Yún, so this issue is central to the whole product. For anyone who intends to use the Yún for something where permanent network connection over long periods of time is crucial (like home automation), this issue makes the Yún basically unusable. So I wonder why there’s seemingly not much attention given to this issue; I can’t be the only one who experiences it?!?

As I said, having basically no experience with OpenWrt, I cannot help much in fixing this issue, but of course I could help tracking it down if it doesn’t reproduce easily, if I’m told what to do/which information to gather.

Uli

[ffissore]

Hi. We have experienced similar problems on our own and pointed our fingers against the abundance of wifi networks surrounding our office (not to mention those created by iphones and such). We ended up using the plain old and reliable ethernet cable.

A solution has been proposed on the forum: scheduling a script for restarting network when pinging google fails
See this and this

I don't think we can just put such a script into every yun and make everyone happy. For example, restarting the network interface, on which you've scripted a python socket to listen to, would probably kill that script. How to restart it properly is a knowledge only you have.

Your thoughts?

[UliZappe]

We ended up using the plain old and reliable ethernet cable.

That’s always preferrable if it’s possible, but there are many situations where it’s not, and clearly you would expect a WiFi equipped device to work in these situations, too.

A solution has been proposed on the forum: scheduling a script for restarting network when pinging google fails

But that's not a fix of the issue; it's a (quite an ugly) workaround.

(BTW, I don't understand why pinging Google was suggested; pinging the router should be sufficient. Constantly pinging Google will probably lead to IP blacklisting on their side; not a good idea.)

I don't think we can just put such a script into every yun and make everyone happy.

Certainly not.

Your thoughts?

I think WiFi is one of the main selling points of the Yún. As such it must work reliably out of the box, and the issue should be really tracked down and fixed.

I never encountered a WiFi enabled device with this kind of problem before. There must be a bug somewhere. For instance, https://forum.openwrt.org/viewtopic.php?id=44877 looked like it was possibly what I would consider an actual fix; unfortunately, the last entry reports that this modification doesn't help either in the latest release version of OpenWrt.

[ffissore]

Your laptop/computer, in attempting to re-establish a broken network connection, is doing the same thing: checking and restarting the network interface at will. Most of the time, this happens without requiring your attention. The difference with the yun is that there is no "network manager" of any sort, so bash comes to the rescue.

Of course we are open to more elegant and reliable solutions.

PS: the last fix you mention was actually applied at a155167 as yun users reported it working

[UliZappe]

Your laptop/computer, in attempting to re-establish a broken network connection, is doing the same thing: checking and restarting the network interface at will.

Yup, but it most certainly doesn't check the connection by pinging Google. And does it break sockets when restarting the network interface (as you mentioned above wrt/ a python script)? I’ve never run into this kind of issue when writing scripts running on computers.

The difference with the yun is that there is no "network manager" of any sort, so bash comes to the rescue.

Once it's clear how to best deal with this issue, a small, dedicated Unix utility in C might be more efficient, no?

Of course we are open to more elegant and reliable solutions.

As I wrote above, I have basically no experience with OpenWrt, so I'm afraid I cannot suggest anything profound here. But from my POV, the first and foremost task would be to have any solution at all that works out of the box and is installed on the Yún by default.

PS: the last fix you mention was actually applied at a155167 as yun users reported it working

Ah, OK, so now we definitely know it doesn’t help here … ;–)

[ffissore]

Yeah, I think it only cares about things like having an IP address or being authenticated with the hotspot

[sngl]

I tried to reproduce the incorrect behaviour with no success. I configured my Yun to connect to an access point, and if I turn off the AP and then turn on again, the Yun recover the connection. I waited 5 minutes and 2 hours before turning on the AP and I tried with WPA2 and with no encryption. I have the latest version of the firmware on my Yun.

[UliZappe]

@sngl
Wel, the problem I reported is slightly different. The AP is always on in my case, that's not the issue. The issue is that the Yun, after some time, loses the connection all by itself for no apparent reason, and then is unable to recover (meaning the connection won’t come up again until the Yun is rebooted). However, it usually takes 12 – 48 hours until this occurs. So this is no problem if you use the Yun for something where you switch it off after usage (because you will hardly use it longer than 12 hours at once), but it's a complete showstopper for any 24/7 application such as home automation.

[UliZappe]

@sngl
Have you tried to reproduce the issue as I described it in my last post? If so, what was the result?

[NerfyGeko]

I've only just started using the Yun myself and came across this topic by chance, but one thing I have seen is that the board seems to get very warm in a short period of time.
If this problem happens (I have not experanced it yet, thought I have not run it for long enough) after 12 to 48 hours do you think the problem is the board is getting slow cooked?
Ideal situation is the Yun has using risers, in a cool place, out of direct sunlight with plenty of ventilation.

Worst case its in a small box, no ventilation outside in direct sunlight bolted hard up agents the floor of the box.

Other factor that may make weird things happen is you power. The yun has no regulator on board and must get a solid 5v (not sure of tolerance. USB standards?). If you are using an unreliable power supply or you get regular power spikes or drops even for a second or so this may cause the voltage to drop below 5v and put the Yun in a bad state.

Don't just rule out the power as I thought my work had very reliable power until I looked at my UPS logs and found we get very short drops over night (never during the day) every few days to a week.

The above may explained why so many people have the problem and why it would affect all 3 of your units.

This may not the issue but it is still worth checking especially for any system that is going to run 24/7.

[UliZappe]

do you think the problem is the board is getting slow cooked?

No. For one, my Yuns don’t get that hot (never more than 40°C / 104°F). And if I reboot them, the connection will last again for at least several hours, although there was no cooling in the meantime.

Other factor that may make weird things happen is you power. The yun has no regulator on board and must get a solid 5v (not sure of tolerance. USB standards?). If you are using an unreliable power supply or you get regular power spikes or drops even for a second or so this may cause the voltage to drop below 5v and put the Yun in a bad state.

Again, I’m quite sure that this isn’t the problem. I use different power supplies for my Yuns, one is USB powered, one is connected to a high quality laboratory power supply and one is connected to its dedicated high quality power supply. Also, the rest of the Yun/Linino keeps working just fine. It’s just WiFi that breaks down.

From what I understand, WiFi is fragile and interruptions might not be unusual. The bug might not be the interruptions as such, but rather that the Yun does not automatically recover from them. (But I’m by no means an expert in this matter.)

[bo01ean]

I too have had similar issues as the OP.
I found changing to super clean power (I.E. laptop USB) and a super strong AP addressed most of my issues.
The Yun's WiFi simply would not boot with certain power supplies.

As previously mentioned, there are no onboard regulators, so ensure your power is clean and consistent. A laptop USB is in spec, and should not fluctuate.

[UliZappe]

Well, as I wrote before, I used various high quality power supplies during my tests, in my case to no avail.

But that’s beside the point. The WiFi connection can get lost for a number of reasons; the important thing is that it will be automatically reestablished as soon as possible. Every WiFi device I know of seems to do that, except the Yun.

Github says that no-one is assigned to this bug, so it seems this will not be fixed (the Yun is 1 year old already …). Why that is is beyond me. This is a most basic, crucial bug that effectively renders the Yun useless for any serious wireless application.

I would certainly volunteer to fix this if I could, but unfortunately, wireless networking is beyond my area of expertise.

Could someone of the Arduino team please comment on the state of this bug?

I’ve invested a lot of time and resources in the Arduino Yun and planned to do various things with it, but if nobody even cares to try and fix this bug, I’ll have to let go and look somewhere else. :–(

[PCcunha]

I´m having this issue too, and for now if i mantain a steady flow of ping packets from my laptop to the arduino it´ll stay up.

There must be a work around.

[isantolin]

Any stranger dmesg debug error when disconnects?