strawberry
Posts: 51
Joined: Tue Oct 30, 2012 10:44 am

Raspberry Pi Zero Wifi signal gets bad after time

Mon Oct 30, 2017 10:12 am

Hi,

I have a Raspberry Pi Zero W setup as a security camera. In the beginning everything was working fine I had good wifi signal / webpage was loading fast. However after a few months the wifi speed was getting slower every week until a certain point where it totally stopped working (ping had like 90% packet loss).

So I decided to buy a new Raspberry Pi Zero and again in the beginning it was working fine, images/webpage were loading fast. Now a few months later it seems like i'm starting to get the same problem, webpage is loading slower every week or not at all and a lot of packets seem to get lost...

notice: I've never changed the location of the Pi.

Anyone had the same problem? Could it be the wifi chip getting too hot and destroying itself? I've already added a fan that cools down the Pi. The CPU temperature stays below 65°C but I don't know if there is a way to measure the temperature of the wifi chip?

SurferTim
Posts: 1769
Joined: Sat Sep 14, 2013 9:27 am
Location: Miramar Beach, Florida

Re: Raspberry Pi Zero Wifi signal gets bad after time

Mon Oct 30, 2017 11:29 am

From a terminal on the Zero W:

Code: Select all

iwconfig
It should give you link quality and signal level. Does it look ok there?

strawberry
Posts: 51
Joined: Tue Oct 30, 2012 10:44 am

Re: Raspberry Pi Zero Wifi signal gets bad after time

Mon Oct 30, 2017 11:52 am

It is around -80DBm / -88DBm

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B.Goode
Posts: 8987
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Location: UK

Re: Raspberry Pi Zero Wifi signal gets bad after time

Mon Oct 30, 2017 11:55 am

Since you don't mention it, I'll ask...

Have you tried rebooting and/or power-cycling the RPi?


And separately, what - roughly - is the ambient temperature around the board with the WiFi interface? (You haven't published a location in your forum profile - do you live somewhere where everyday temperatures might be a concern?)

SurferTim
Posts: 1769
Joined: Sat Sep 14, 2013 9:27 am
Location: Miramar Beach, Florida

Re: Raspberry Pi Zero Wifi signal gets bad after time

Mon Oct 30, 2017 12:12 pm

That is a very bad signal. You should try for -70dBm or better. How far is the Zero from your AP? Anything blocking line of sight?

strawberry
Posts: 51
Joined: Tue Oct 30, 2012 10:44 am

Re: Raspberry Pi Zero Wifi signal gets bad after time

Mon Oct 30, 2017 12:23 pm

Yes i've tried reboot but doesn't solve the problem unless I pull the power plug for 10-15 minutes after that it works better again for a short time.

Outside temperature is around 10-15°C a.t.m. in Belgium so not really hot, of course the Raspberry is inside a water proof box where ambient temperature may be a bit higher.

Distance is +/- 10m and has 1 wall in the line of sight.

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hansotten
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Re: Raspberry Pi Zero Wifi signal gets bad after time

Mon Oct 30, 2017 12:26 pm

What you describe sounds more of a resource problem leading to slower response.

You did not tell us what software you are running, or whether you started with a fresh SD card on your second Pi, so I guess things to check:

- SD card wearout
- SD card corruption
- does the camera store images on the SD card and does not delete periodically, card nearly full?
- SD card contact problems

Heat may destroy hardware, but SD card is more vulnerable than the rest of the electronics in my experience.
http://duinorasp.hansotten.com for Raspberry Pi and Arduino and ESP8266
http://retro.hansotten.nl for retrocomputing with the 6502 cpu

strawberry
Posts: 51
Joined: Tue Oct 30, 2012 10:44 am

Re: Raspberry Pi Zero Wifi signal gets bad after time

Mon Oct 30, 2017 12:38 pm

I'm using the IP camera software from https://github.com/silvanmelchior/RPi_C ... erface.git, I'm also using this on another Raspberry which is connected with LAN interface without problems.

SD card is a high endurance card and images are automatically deleted after a week, CPU usage is around 5%.

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