request for help with RTL_433 + 2832 RTL-SDR DVB and 915Mhz no decode LaCrosse

[Tim Reimers KA4LFP]

Hi all -

New here --

I have a Raspi running rtl_433, which can successfully decode LaCrosse 2310 data at 433 Mhz. That's a 2310 weather station at 433 Mhz on a 25' pole.

I provide that info just to clarify the fact that I do have a known working setup with all required libraries, collecting data, etc.... 

I'm trying to get the same SDR to now switch and read a LaCrosse LTV-R1 rain guage

that transmits at 915 Mhz.

I can see the bursts of data (or something) every so often on SDR-Sharp,  and the indoor LCD display is reading the unit outdoors, and is right next to the Pi.

Burst data does appear to be centered very close to 915Mhz.

But when I put -f 912000000 or -f 915M , it does switch to 915Mhz,

but will not decode my LaCross LTV-R1 raingauge...

I also have a LaCross TX32U-IT that isn't decoding - 

Again -- with the exact same setup, omitting the -f 915M 

makes it tune to 433Mhz, and it immediately starts to decode things.

Is there some other option I also need at 915Mhz???

The command I'm using is

/usr/local/bin/rtl_433 -f 915M -F json

rtl_433 version 20.02-146-g7164f4a branch master at 202009121810 inputs file rtl_tcp RTL-SDR

Use -h for usage help and see https://triq.org/ for documentation.

Trying conf file at "rtl_433.conf"...

Trying conf file at "/root/.config/rtl_433/rtl_433.conf"...

Trying conf file at "/usr/local/etc/rtl_433/rtl_433.conf"...

Trying conf file at "/etc/rtl_433/rtl_433.conf"...

New defaults active, use "-Y classic -s 250k" for the old defaults!

Registered 137 out of 166 device decoding protocols [ 1-4 8 11-12 15-17 19-21 23 25-26 29-36 38-60 63 67-71 73-100 102-105 108-116 119 121 124-128 130-149 151-161 163-166 ]

Found Rafael Micro R820T tuner

Exact sample rate is: 1000000.026491 Hz

[R82XX] PLL not locked!

Sample rate set to 1000000 S/s.

Tuner gain set to Auto.

Tuned to 915.000MHz.

The 

[Christian Z.]

If the signal is exactly centered it will help to tune away a bit (avoid DC), e.g. -f 914.9M.

You can try a lower sample rate (narrow band = less noise) if you know where the signal is, e.g. -s 250k

You can try the other, older demod, e.g. -Y classic.

I don't really know what to recommend, if it's DC, sample rate or the demod, let me know what works!

[Blaine Horrocks]

While I don't have a rain gauge, 

rtl_433 -f 914900000 -s 250k

detects my LaCrosse TH3 temperature and humidity sensor:

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

time      : 2020-11-29 08:55:49

model     : LaCrosse-TH3 Sensor ID : 13xxxx

Sequence  : 3            unknown   : 0             Temperature: 1.9 C        Humidity  : 78 %          Integrity : CRC

[Jesse Kohn]

What kind of range do you get between your sensor and the receiver? Would you mind telling me what SDR setup you are using / antenna type? I have the same sensor but the signal seems quite weak or I don't know what i'm doing... as soon as I move it outside I can't pick data up. Works fine in the same room and a short distance away within the house. It wouldn't be practical for me to have the antenna mounted outside but i'm tossing up whether it'd be worth picking up a dedicated 915Mhz antenna. Obviously the signals penetrate my house just fine as the LaCrosse indoor unit has no problem receiving the data from much further away!

[Blaine Horrocks]

It's about 18 metres, with three wooden stud walls and a layer of brick.  The SDR I have is one I got off Amazon a few years ago.  or was it Adafruit?   It's detected as "Found Rafael Micro R820T tuner", small, black, 2cm square. I'm using the stock magnetic whip antenna. 

Fresh batteries in the TH3?   

I did have an epic fail with a home built coax antenna.   A good ground plane is essential so you could check the base of your antenna.  In my whip antenna the base was a bit loose, and I had to solder in the micro-coax shielding to the metal / magnetic base of the antenna. 

I'd also suggest looking at cubeSDR or similar and look at the signals on the display.  The SDR has a fairly narrow frequency range that it will pickup, and if you are off just a bit you can miss the packets.    And of course the transmitters are not necessarily all that finely tuned.  

hope that helps

 

--
You received this message because you are subscribed to a topic in the Google Groups "rtl_433" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/rtl_433/GkUvanaNglU/unsubscribe.
To unsubscribe from this group and all its topics, send an email to rtl_433+u...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/rtl_433/46d91101-6b51-448e-91f2-6c8f2fd63a91n%40googlegroups.com.

[Jesse Kohn]

Yep both sensors have fresh batteries. I have the dipole from the RTL-SDR kit with the short antenna connectors at around 8cm each (and the SDR usb device itself too. https://www.amazon.com.au/RTL-SDR-Blog-RTL2832U-Software-Telescopic/dp/B011HVUEME/ref=asc_df_B011HVUEME/?tag=googleshopdsk-22&linkCode=df0&hvadid=341774294791&hvpos=&hvnetw=g&hvrand=218843545669740078&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9069312&hvtargid=pla-521867821094&psc=1 )

maybe the dipole just isn't as effective on this frequency or the base it connects to just isn't solid enough.. not sure. I'm a total amateur with this stuff. Was thinking of getting one of the following: https://au.element14.com/siretta/delta22b-x-smam-s-s-20/915mhz-ism-band-115mm-small-antenna/dp/3020310

I'll keep playing around with SDR Sharp to see if i can pinpoint the frequency my particular sensors broadcast on & see if i can work out how far I can catch the signal indoors (my hallway should provide a reasonable test "tunnel"!

[Tolip Wen]

I have had excellent results with a Tram 1089-SMA Scanner Mini-Magnet Antenna.

I have 3 of them in use indoors, purchased seperately over the last few years. I keep buying one to deploy outdoors and end up just sticking it on a different SDR. It works well for me @ ~915MHz. I have an outdoor Ambient Wx about 100 meters(300ft) away. I also have an Ecowitt Wx that I use for calibrating anemometers that I design/dabble with and have to hide from the antenna if in the same room.

Your mileage may vary, I'm NOT an antenna-ologist! All I know is I tried a few of the common/popular SDR antenni and I was underwhelmed. Then I tried the Tram 1089 and I've been a happy camper ever since.

It's not magic it's tuned. It's tuned to what many rtl_433 users are specifically interested in.

I also use em for broadcast FM, air traffic control, ADS-B(1060MHz), railroad scanner, fire dept., etc.

One of the evil overlord places has it for about the same price as the whip mentioned earlier.

https://www.amazon.com/1089-BNC-Mini-Magnet-800MHz-1-BNC-Male-Connector/dp/B01DY8FOK0/ref=sr_1_27?crid=173FR4Y11OVYP&dchild=1&keywords=tram+antenna&qid=1610218715&s=electronics&sprefix=tram%2Celectronics%2C181&sr=1-27

--
You received this message because you are subscribed to the Google Groups "rtl_433" group.
To unsubscribe from this group and stop receiving emails from it, send an email to rtl_433+u...@googlegroups.com.

To view this discussion on the web, visit

https://groups.google.com/d/msgid/rtl_433/CAJGL92kcpqpXQHk%3DQP%2BYsZaZDby5-2FyC-UjEXgYqNDrWs5%2B9Q%40mail.gmail.com

.

[Tolip Wen]

The link I posted previously was for the BNC flavor. I intended to link to the SMA male terminated one.

https://www.amazon.com/1089-SMA-Mini-Magnet-800MHz-1-SMA-Male-Connector/dp/B01DY8FTD2/ref=psdc_3236443011_t3_B01DY8FOK0