Interference from other 433MHz devices

[Andrew Wilkinson]

Hi all,

I've been having a problem with my WH2080 losing connection to the sensors. I've been trying various things to track the problem down, including moving it around and turning various electrical devices on and off. I think I've tracked it down to interference from my CC128 electricity monitor (http://www.currentcost.com/product-cc128.html) which also broadcasts on 433 MHz. I suspect that when the weather station and cc128 broadcast at the same time they interfere, and the weather station 'loses' because the transmitter is further away. The problem is that the disconnect is temporary and irregular, but happens often enough to be irritating.

 

I was wondering if any one else has had a similar problem? I'm not sure what the best solution is because I want to track both, and I want to connect them to same pc so I have to have them close to each other!

At the moment I have my weather station disconnected and have it closer to the transmitter. I then plug it in occasional and download the data, but this means that my website (http://www.welwynweather.co.uk) it far from the live data I would like!

Any advice appreciated.

Thanks!

Andrew

[Jim Easterbrook]

On 14/02/13 20:30, Andrew Wilkinson wrote:
>
> I've been having a problem with my WH2080 losing connection to the
> sensors. I've been trying various things to track the problem down,
> including moving it around and turning various electrical devices on and
> off. I think I've tracked it down to interference from my CC128
> electricity monitor (http://www.currentcost.com/product-cc128.html)
> which also broadcasts on 433 MHz. I suspect that when the weather
> station and cc128 broadcast at the same time they interfere, and the
> weather station 'loses' because the transmitter is further away. The
> problem is that the disconnect is temporary and irregular, but happens
> often enough to be irritating.
> I was wondering if any one else has had a similar problem? I'm not sure
> what the best solution is because I want to track both, and I want to
> connect them to same pc so I have to have them close to each other!

The receivers need to be close to the PC - each transmitter can be as
far away as possible. If the receivers have aerials that are at all
directional you might be able to exploit this. If the unwanted source is
90 degrees away from the wanted source for each system you might be able
to reduce the interference. (Aerials often have a sharper notch where no
signal is received than main lobe for max signal, so being a bit off
axis might not reduce the wanted signal much, but could greatly reduce
the interference.)

Curiously just today someone has mentioned a similar interference source
on the Cumulus forums:
http://sandaysoft.com/forum/viewtopic.php?f=13&t=4507&start=30 (message
timed 12:07 from 'mr.sneezy').

> At the moment I have my weather station disconnected and have it closer
> to the transmitter. I then plug it in occasional and download the data,
> but this means that my website (http://www.welwynweather.co.uk) it far
> from the live data I would like!

Set up a low power secondary box (SheevaPlug or RasPi or similar) for
one of the systems? Or swap your station for an 868MHz one?
--
Jim Easterbrook <http://www.jim-easterbrook.me.uk/>

[goo...@wittongilbert.free-online.co.uk]

On 2013-02-14 20:30, Andrew Wilkinson wrote:

I was wondering if any one else has had a similar problem? I'm not sure what the best solution is because I want to track both, and I want to connect them to same pc so I have to have them close to each other!

 

No experience of this but I suspect that this is the right diagnosis.  The Raspberry pi guys were working on actually reading the transmitted signals which may provide a solution but I haven't heard any outcome from that.

 

Two or three possible "work arounds":

 

1. Long USB cables to each receiver (think the USB standard is max 5m without needing to go to extremes of adding powered hubs etc.)  That could allow you to increase the distance between the two receivers by 10m (PC in the middle).  If the transmitters are possitionable at different exteremes too this might JUST be enough?

 

2. Sheild the aerial of the WH2080 with some earthed metalwork from the angle of the transmitter?

 

3. Move the WH2080 away as you have, but connect it to something low powered to collect the data like a RasPi or a small router.  Use Ethernet or WiFi to then get the info to the other computer.

 

[Andrew Wilkinson]

Hi,

Thanks for the quick replies and suggestions.

A Raspberry Pi had crossed my mind, but it'll add more complexity and frankly I'm running out of plugs for gadgets in my house!

I don't know why I didn't think of longer USB cables, I'll definitely give that a try first. It seems to work fine on the other side of the room so if I can get it there with a long cable that should solve the issue.

Cheers,

Andrew

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