Author Topic: Receiving Davis Vantage weather data with a RTL-SDR dongle  (Read 1035 times)

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Offline lui

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Re: Receiving Davis Vantage weather data with a RTL-SDR dongle
« Reply #25 on: March 15, 2019, 08:55:50 AM »
I tried modified version of rtldavis and getting some data from my station. Would be great if it will work some day.

Offline Lucas

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Re: Receiving Davis Vantage weather data with a RTL-SDR dongle
« Reply #26 on: March 15, 2019, 11:25:44 AM »
Just try the rtldavis program with your frequencies. Then you will know what I mean.

Offline lui

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Re: Receiving Davis Vantage weather data with a RTL-SDR dongle
« Reply #27 on: March 17, 2019, 03:28:07 PM »
Is that output good?

20:24:41.375016 TRANSMITTER 0 SEEN
20:24:41.376999 Hop: {ChannelIdx:2 ChannelFreq:868360000 FreqError:-11307}
20:24:43.936956 5006C1FF7300EA68 2 0 0 0 0 msg.ID=0
20:24:43.937267 Hop: {ChannelIdx:4 ChannelFreq:868603000 FreqError:-11074}
20:24:46.500670 4006B70001003458 3 0 0 0 0 msg.ID=0
20:24:46.500978 Hop: {ChannelIdx:1 ChannelFreq:868238000 FreqError:-8901}
20:24:49.062644 8005B28E0100F8A4 4 0 0 0 0 msg.ID=0
20:24:49.062956 Hop: {ChannelIdx:3 ChannelFreq:868490800 FreqError:-9375}
20:24:51.624519 E004B5460300B5F4 5 0 0 0 0 msg.ID=0
20:24:51.624850 Hop: {ChannelIdx:0 ChannelFreq:868118000 FreqError:-7641}
20:24:54.188440 5004BAFF710094E3 6 0 0 0 0 msg.ID=0
20:24:54.188736 Hop: {ChannelIdx:2 ChannelFreq:868360000 FreqError:-7035}
20:24:56.750544 duplicate packet: 5004BAFF710094E3
20:24:56.814898 ID:0 packet missed (1)
20:24:56.815183 Hop: {ChannelIdx:4 ChannelFreq:868603000 FreqError:-5848}
20:24:59.312580 9003B90C030AA3A8 7 0 0 0 0 msg.ID=0
20:24:59.313780 Hop: {ChannelIdx:1 ChannelFreq:868238000 FreqError:-11067}
20:25:01.875945 8003B98E03004D5C 8 0 0 0 0 msg.ID=0
20:25:01.876368 Hop: {ChannelIdx:3 ChannelFreq:868490800 FreqError:-10482}
20:25:04.438088 E004BD4603003037 9 0 0 0 0 msg.ID=0
20:25:04.438413 Hop: {ChannelIdx:0 ChannelFreq:868118000 FreqError:-8013}
20:25:07.002012 5006ACFF7100EC5E 10 0 0 0 0 msg.ID=0
20:25:07.002317 Hop: {ChannelIdx:2 ChannelFreq:868360000 FreqError:-11009}
20:25:09.563924 C007B20B71000EC4 11 0 0 0 0 msg.ID=0
20:25:09.564230 Hop: {ChannelIdx:4 ChannelFreq:868603000 FreqError:-9363}
20:25:12.125514 8005B78E010044E1 12 0 0 0 0 msg.ID=0
20:25:12.126687 Hop: {ChannelIdx:1 ChannelFreq:868238000 FreqError:-5994}
20:25:14.689551 duplicate packet: 8005B78E010044E1
20:25:14.752289 ID:0 packet missed (1)
20:25:14.752580 Hop: {ChannelIdx:3 ChannelFreq:868490800 FreqError:-10641}

Offline Lucas

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Re: Receiving Davis Vantage weather data with a RTL-SDR dongle
« Reply #28 on: March 17, 2019, 03:40:15 PM »
Hi Lui,

Yes, this is the normal logging. A 'packet missed' percentage of 10-15 percent of the total to be received messages is normal.
With only one transmitter active the percentage of missed messages will be lower.

Program weewx (with the weewx-rtld driver installed), will run rtldavis, parse the raw messages and store the parsed data in the weewx datbase.
For weewx-rtld see: https://github.com/lheijst/weewx-rtld

Luc

Offline kobuki

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Re: Receiving Davis Vantage weather data with a RTL-SDR dongle
« Reply #29 on: March 17, 2019, 03:50:27 PM »
It's worth noting that the real discussion is going on in the following threads, for anyone interested:

https://groups.google.com/forum/#!topic/weewx-development/jhGleLxu-p0
https://groups.google.com/forum/#!topic/weewx-user/ZjDVbSmwmZY

Offline mcrossley

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Re: Receiving Davis Vantage weather data with a RTL-SDR dongle
« Reply #30 on: March 17, 2019, 05:00:59 PM »
My 2p worth, I found the US frequencies matched the Auruido code values almost exactly using my offset corrected RTL dongle - which is also very temperature sensitive! I have to leave it running for some time to stabilise.

There is also a fair bit of variation between different transmitters, I did not record the frequency offsets sadly. The VP2 consoles also vary, Davis "tune" each one with an offset value, I have tweaked this console offset to match my console to my ISS better.
« Last Edit: March 17, 2019, 05:12:48 PM by mcrossley »
Mark

Offline kobuki

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Re: Receiving Davis Vantage weather data with a RTL-SDR dongle
« Reply #31 on: March 17, 2019, 05:02:51 PM »
My 2p worth, I found the US frequencies matched the Auruido code values almost exactly using my offset corrected RTL dongle - which is also very temperature sensitive! I have to leave it running for some time to stabilise.

Yes - for me too. There's a bug in the original demodulator code that breaks the frequency settings somehow. Luc is trying to find that.