Please read the posts in the Announcements section about the current status of Cumulus development now that I have retired

Please read this post before posting

Latest Cumulus release v1.9.4 (build 1099) - Nov 28 2014
Latest Cumulus MX release - v3.0.0 build 3043 Jan 20 2017. See this post for download

Cumulus 1 and SDR radio

Discussion specific to Fine Offset and similar rebadged weather stations
g0gcd
Posts: 4
Joined: Fri Jul 20, 2012 6:57 pm
Weather Station: Fine Offset WH1081
Operating System: Windows 7
Location: Rothwell NN14 6JE
Contact:

Cumulus 1 and SDR radio

Postby g0gcd » Sun Aug 28, 2016 11:19 am

I have used the WH1081 for 4 years, with little trouble (usual sensor wear and tear and bird poop). Recently, a new radio signal popped up on 433.92. This repeatedly sent a 250ms burst every 10 seconds or so, starting at around bedtime. Due to the Fine Offset communications protocol, this didn't give problems until typically around 2-3am when it knocked my sensors out of synch with the console. This resulted in an 'outage' of up to 12 hours until the pair re-synchronised.

I tried fitting an external antenna and making it directional but because the console itself is not screened, I couldn't prevent the disruption from the interfering signal.

So next, I tried a WH3080 on 868 MHz. I checked that the frequency was clear before purchase (smart move, eh?) and installed the new station last weekend. First disappointment - 868MHz only seems to carry half the distance of 433MHz, which in my case is to the bottom of the mast but not indoors. I eventually found a windowsill where I could perch the console and get synchronisation and then began the physical migration of the associated PC to that location. However, in the meantime, Second disappointment - the WH3080 stopped sending wind direction - a fault eventually traced by substitution of parts to the sender transmitter, so that's now on it's way back for replacement. That's the end of 868 for me, for now.

Anyway, apologies for the lengthy background but it explains why I am considering another option.
The Fine Offset stations are known for two problems (apart from batteries, sensors and transmitters), namely 'loss of the sensor' and 'breakdown of the USB'. I was considering whether the console could be eliminated completely by the use of a USB TV Stick operating as an SDR radio receiver, plugged directly into the stations PC.

My theory is that by having better control of the receiver and not having to worry about power supply, I could implement a more sophisticated interference handling regime, allowing me to return to the longer range 433MHz band. Instead of waiting for the 12 hours for the two parties to drift back into alignment, a more intelligent algorithm could be used to determine the timing drift between console and transmitter, predicting better when the transmitter is on, thus reducing the relocking time. Also, by having the receiver in the PC, there is no console to PC USB link to fail, thus eliminating that problem as well.

So, to the two questions that I have (and these may belong in two threads):
Has anyone implemented an SDR receiver for the Fine Offset series of stations (and are they willing to share that?)
Is there a way of inputting the extracted data from the 'receiver' into Cumulus, bypassing the USB input (for example, can it be done using the EasyWeather file?)

Would appreciate any input before I launch myself into this quest..

As another approach, I am also considering the use of passive radio repeaters to reflect the 868MHz signal from the mast into the room where the console is - if I get a working 868MHz system back!

Currently off line :cry:

John
Rothwell NN14

User avatar
PaulMy
Posts: 1547
Joined: Sun Sep 28, 2008 11:54 pm
Weather Station: Davis Vantage Pro 2 w/Envoy USB
Operating System: Windows-8
Location: Komoka, ON Canada
Contact:

Re: Cumulus 1 and SDR radio

Postby PaulMy » Sun Aug 28, 2016 1:33 pm

Is there a way of inputting the extracted data from the 'receiver' into Cumulus, bypassing the USB input (for example, can it be done using the EasyWeather file?)

I don't have a FineOffset nor easyweather.dat so can't answer but this may help to understand http://wiki.sandaysoft.com/a/EasyWeathe ... eather.dat

Enjoy,
Paul

User avatar
VTHokie74
Posts: 130
Joined: Tue Apr 10, 2012 12:58 am
Weather Station: Davis Vantage Pro 2
Operating System: Rasbian
Location: Ashland, KY

Re: Cumulus 1 and SDR radio

Postby VTHokie74 » Sun Aug 28, 2016 1:50 pm

That is an interesting concept. Do you know what kind of encoding FO uses for the transmitted data? I wonder if there would be a market for a "headless" weather station consisting of a sensor array and a USB dongle? I hardly need a console for my Davis. If I want to see the values I can just use my phone, tablet or a PC.
Station: Davis Vantage Pro 2/CumulusMX/Raspberry Pi 3

User avatar
steve
Cumulus Author
Posts: 26247
Joined: Mon Jun 02, 2008 6:49 pm
Weather Station: None
Operating System: None
Location: On tour in France
Contact:

Re: Cumulus 1 and SDR radio

Postby steve » Sun Aug 28, 2016 1:57 pm

I know nothing about SDR radio, but have you looked at the Weatherduino? This uses Fine Offset (and other) sensors, and gets its data into Cumulus by the very neat approach of emulating a Davis weather station.
Steve
-----
Hosting available for Cumulus web sites. See http://sandaysoft.com/forum/viewtopic.php?f=2&t=11876

Please read the posts in the Announcements section about the current status of Cumulus development now that I have retired

g0gcd
Posts: 4
Joined: Fri Jul 20, 2012 6:57 pm
Weather Station: Fine Offset WH1081
Operating System: Windows 7
Location: Rothwell NN14 6JE
Contact:

Re: Cumulus 1 and SDR radio

Postby g0gcd » Sun Aug 28, 2016 3:43 pm

Thanks for the steers.
I am currently looking at the weatherduino solution that you've pointed at, but can't quite yet get my head around what I need to buy and what I can build. I can see how to use my current sensors, so this approach looks like it might be a go-er. I can probably review the source code for the radio comms to see if it can handle my particular problem with interference.
If not, then there's always the TV Stick approach. It's so annoying that I can clearly hear my 'wanted' signal on my walkie talkie, so it shouldn't be difficult to get it out - but the weatherduino might be an easier option!
I'll let you know how I get on. Thanks again
John

User avatar
VTHokie74
Posts: 130
Joined: Tue Apr 10, 2012 12:58 am
Weather Station: Davis Vantage Pro 2
Operating System: Rasbian
Location: Ashland, KY

Re: Cumulus 1 and SDR radio

Postby VTHokie74 » Sun Aug 28, 2016 6:20 pm

SDR stands for software defined radio. The short description is that a variable RF oscillator is used to mix RF signals down to a frequencies that a PC sound card can handle. Then the tuning, filtering, detection, etc. can be handled digitally in the PC. If you go to websdr.org you can tune and listen to various SDR's around the world.
Station: Davis Vantage Pro 2/CumulusMX/Raspberry Pi 3

AllyCat
Posts: 997
Joined: Sat Feb 26, 2011 1:58 pm
Weather Station: Fine Offset 1080/1 & 3080
Operating System: Windows XP SP3
Location: SE London

Re: Cumulus 1 and SDR radio

Postby AllyCat » Mon Aug 29, 2016 9:10 am

Hi John,

Concerning the 3081, did you test the range with the USB cable disconnected ? At least the 434 MHz version is well known to radiate inferference from the USB port and a better cable may help.

g0gcd wrote:I have used the WH1081 for 4 years,


The first consideration is whether that station uses the "Old" Fine Offset wireless protocol or the "New" one. Surprisingly, the old protocol used a complex (FM/FSK) wireless chip, whilst the new ones (including the 308x) use simple OOK (On-Off-Keying). I've never had any success capturing/decoding the old protocol but the new one is easy. For example, search for information from Kevin Sangalee and/or on the Raspberry Pi forum.

All the senosrs on the FO stations are "compatible" (with the exception that the Solar Pod needs to connect to an appropriate T/H transmitter) and the wireless protocols are also compatible (the 308x transmits an additional "Solar Data" packet). Obviously a 434 MHz transmitter cannot "talk" to a 868 MHz Console, or vice versa, but it did appear that it (now) might be possible to swap only the radio receiver module.

Unfortuantely, the WeatherDuino uses the Arduino "VirtualWire" library for its wireless protocol, so you need to "hack" that to transmit/receive data for the WeatherDuino (or of course use an Arduino). It's something I want/need to do in the future (or hope somebody else will do first) but I don't yet know if it will be better to port VirtualWire onto my processor, or to receive the FO protocol into some modified Weatherduino code (as was done for the "AuriolDuino" version).

Cheers, Alan.

g0gcd
Posts: 4
Joined: Fri Jul 20, 2012 6:57 pm
Weather Station: Fine Offset WH1081
Operating System: Windows 7
Location: Rothwell NN14 6JE
Contact:

Re: Cumulus 1 and SDR radio

Postby g0gcd » Thu Jul 13, 2017 8:27 pm

Well, I didn't get very far with the SDR approach. I had a little problem with my carrier smashing up the faulty 868 unit on return and having to go through the insurance claim rigmarole.

The 868 MHz unit is now on and running well. Well, for about 9 months... Guess what, the interference has now cropped up on the 868 MHz band as well, so I'm starting to get lockouts There. Yes it is interference, I have some sophisticated radio gear which allows me to hear exactly what's going on at that frequency...

So, another approach occurred to me. Has anyone tried using two radio links in diversity? I can believe that the single set of sensors could be tee'd into the 868 and 433 transmitters and I have the two consoles. I have sufficient PCs to support the consoles but haven't yet thought through how I could use my network to pass data from the 'working' link to a single database/Cumulus instance to drive the website.

As a result of the issue with postage, I actually have two 868 consoles and had considered the same approach using the one transmitter to the two consoles but I am thinking that it's unlikely that the alarm system (or whatever 'cordless' gizmo it is) would hit 868 and 433 at the same time, allowing the links some time to re-sync.

Or perhaps, two Cumulus'es with a switch, so that when the primary link 'loses sensor contact', it stops sending to the web and allows the secondary to take over. There's some options here (but it would be really nice if there was a more solid synchronisation in the FO units!)

Thoughts?

Thanks
John

philcdav
Posts: 240
Joined: Tue Jun 24, 2008 9:43 pm
Weather Station: MyDEL WX2008 Mk2 Fine Offset
Operating System: XP and W7
Location: Maghull, nr Liverpool, UK
Contact:

Re: Cumulus 1 and SDR radio

Postby philcdav » Fri Jul 21, 2017 11:55 am

Hi John

Interested in SDR possibilities myself but thats for another day.

I wonder if you have tried a slightly different 'directional aerial' solution?

The console aerial could be made directional by fitting a reflector behind the unit.

There are several designs for paper/foil based reflectors ...

http://www.instructables.com/id/DIY-WIF ... n-Booster/

https://www.google.co.uk/search?q=paper ... Ywq3X0zmWM:

A cheap and cheerful approach that may work.

Another solution could be to beam signals directly at each other. Or, how about cable? is the distance great? TV coax would do.

Regards - Phil (G0DOR -qthr)
Phil - G0DOR


Return to “Fine Offset/EasyWeather”

Who is online

Users browsing this forum: No registered users and 6 guests