Reviving my WX station, now with RTL-SDR.

 I've setup my WX station (Maplin version of WH1080) for quite sometime now but since last year, it went down due to few reasons. One of it, because the problem with the intermediary software between the WX base station and aprs server. Anyway, the outdoor unit still out there, transmitting it data over 433.920Mhz freq. 

Had a bit of time yesterday, and I've received the BNC to SMA jumper cables that I ordered through Shoppe few days back, so no reason not to go ahead with this. My Raspberry 4 mini-server is under-load anyway, and the RX only multi-coupler given by Weerut has been laying down collecting dust for quite sometime. 

What needed to get the SDR to receive the WX data from WH1080 is a software called rtl_433. This software runs on my Raspbian without a problem and it could actually receive many other devices that use 433MHz frequency. 

To get started, I was using the instructions found in :

GitHub - matthewwall/weewx-sdr: weewx driver for software-defined radio

Few things needed to be changed since the rtl_433 has been updated, WH1080 support has changed too. The weewx-sdr won't work out of box. The following changes still not available in the final code. 

Resolve #79 - new model name and wind fields in RTL-433 V20 by mitchins · Pull Request #88 · matthewwall/weewx-sdr · GitHub

To be able to send the output into aprs, I'm using the setup that I've had since 2015. This extension is a modified code, not written by me but it works great my setup. My write up on the weewx2aprx can be found here.

9M2TPT / KT2O / M0HIK: Getting your WX station out to RF using weewx + aprx

My current setup as below ( yes, I'm using multi-coupler for my setup which is connected to Diamond D190).

Oh am going to redo the power into the multi-coupler, it kind of dangerous using the croc-clip for it for sure :)

Getting your WX station out to RF using weewx + aprx

I have been using my WH1080 since two years ago and it is still working great until few days ago when I found out that the anemometer doesn't seem to give any reading anymore. Anyway, other than that, everything still working just fine.

I have been experimenting with Raspberry Pi for quite sometime and I've moved my WX and aprx along with few local server apps into Raspberry Pi (previously on my router running OpenWRT). Anyway, for this post, I'm going to guide you on how to get the WX data into RF without a need of the Internet connection after the first setup.

What needed?

1. Raspberry Pi, I'm using raspbian. I'm not going in details on how to set it up. By now you should've been able to get this up and running.
2. weewx software, more information can be found in http://www.weewx.com/. Installation guide can be found here: http://www.weewx.com/docs/debian.htm
3. A weewx extension that I've adopted from cwxn extension so it could produce an aprx ready beacon file can be found here: weewx2aprx-0.4.zip (old deprecated package ->) weewx2aprx-0.1.tgz
4. Aprx package which can be found here (prepackaged): http://thelifeofkenneth.com/aprx/debs/

After you've got everything installed, the weewx and aprx package. You can install the weewx2aprx extension, to do this, just use the following command:

wee_extension --install weewx2aprx-0.1.tgz

          wee_extension --install weewx2aprx-0.4.zip   

You need to edit the /etc/weewx/weewx.conf. Toward the end of the configuration file, there is a new section created by the above extension installer. Edit as required, the necessary fields are the lat, lon and the note.

# Options for extension 'aprx'

[Weewx2APRX]

    lat = 0312.81N

    note = "WH1080+weewx+aprx Sg Buloh, Malaysia"

    symbol = /_

    lon = 10133.17E

    filename = /var/tmp/aprx_wx.txt 

Change the above to suite your preference and rerun the weewx's service by issuing the following commands:

$ sudo /etc/init.d/weewx stop 

$ sudo /etc/init.d/weewx start 

Edit your /etc/aprx.conf file and add the following information under the beacon, change the callsign as necessary :

        beaconmode radio

        beacon srccall 9M2TPT-13 \                                             

              via WIDE1-1,WIDE2-2 \                                            

              file /var/tmp/aprx_wx.txt

 That should be it.

Maplin N96GY(WH1080) WX station + APRS

During my trip back to Manchester last month, I've got myself a cheapo WX station. Sold by Maplin under it's Maplin Gadget brand with N96GY model, I made to understand by reading some of the documentation found in Maplin website, it is an OEM from Fine Offset Electronics which produces few variants of the WX station with USB connectivity. I was a bit hesitate to buy it at first since 1) it is cheap 2) getting it to connect to a router will be a hassle. After few more research, I found out that there is a package called FOWSR available for OpenWRT and the price paid might be worth it to get it up for a year or so before getting something better/more expensive.

Assembling the unit is a no brainer, don't think you need to look at the manual to get the outdoor unit assembled. I've got it mounted on my porch since my house only has a small garden. For those who're thinking of putting a weather station, you should follow the one suggested here:

http://wiki.wunderground.com/index.php/PWS_-_Siting

Anyway, the next hurdle is to get FOWSR to talk to aprs-is server. The FOWSR software was developed quite sometimes back and it hasn't been enhanced further. It supports the following format:

• Weather Underground
• PWS Weather
• pywws
• XML

Left from the supported format is the APRS/CWOP format. I was looking to enhance the FOWSR but I couldn't get some of the libraries to compile properly using OpenWRT SDK (couldn't find this lib: libusb-compat), I might need to get the full source and recompile everything. But lucky me, I found someone using the same weather station + fowsr and his WX packet can be found on the aprs.fi. Emailed the packet owner, Nick (VA3NNW) to get more information on how he got his stuff running and he sent me a perl wrapper code that will reformat wunderground format into APRS/CWOP format. Thanks Nick for your help .. my WX station is up and running now and can be found here:

http://aprs.fi/weather/?call=9M2TPT-13

BTW, I've a workaround to have the WX packet to back-feed into the RF, by using aprx. What need to be done is to put a filter in section and in the section. If I ever get the OpenWRT SDK working, I might use it to output into a text file and let aprx to beacon out from the text file, this will then get picked up by other igate and into the aprs.fi. But for now, my current setup is working just fine.

I've modified Nick's perl script a bit to output a file into a /tmp directory instead of sending it direct to the APRS-IS server. I'm using aprx to beacon out from this text file into RF and back into aprs-is from someone's igate. This is now work well.

Nick has changed a bit on how his scripting works now, he is using CGI. For those who're interested in Nick's perl script, do head up to his page at:

http://noseynick.net/wx/noseywx.html