Getting Temp from La Crosse transmitter


 
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Dave Robson

New member
I apologize if this has been covered but I've been searching for an hour and can't find a solution.

I've just finished assembling my HM 4.0 and am trying to get an ambient temperature reading from my La Crosse weather station. It looks like it's seeing the transmitter but it's not reading the temperature, it's just saying "OFF". Here's a screen shot of the configuration:

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On the plus side I have my web server working.
http://chargriller.bbqroast.net/luci

Dave!
 
What you're seeing in the configuration is the receiver, the HeaterMeter. The negative quality means that it is getting CRC errors on the packets. Did you install an antenna onto the RF module? For 915MHz that's a 78mm piece of wire attached to the antenna pin of the RF module.
 
Yes there's a a 78mm grey wire soldered into the board.

https://www.flickr.com/photos/31312887@N04/14393029436/

I moved the whole unit to the window where the sensor is so there's just glass separating them and the signal is -9. So it sounds like the module is functioning it's just not getting a good signal then? I stood the wire up perpendicular to the PCB and the signal dropped to -11. Maybe I'll resolder the wire and recheck it. Is the 78mm the length of copper including the 1-2mm sticking through the PCB or is it that critical?

Thanks for the help.
Dave!
 
It seems like the HeaterMeter is communicating to the RF module on board, but they don't really have good signal strength meters so the number you're looking at isn't a signal strength meter. It's a count of how many messages failed checksum vs succeeded. Once a message passes checksum it can get its ID read and then you can see the signal strength (which is a 0-3 value displayed as an icon). What model transmitter is it? It might be a packet format that I've not seen before so the checksum method isn't working. I only have tested with a TX28U-IT and TX29UDTH-IT (if memory serves).

The wire length isn't super critical but it is measured roughly from where it goes into the PCB. A mm here or there doesn't affect signal strength enough to fail checksum every time, it just would reduce the range from like 40ft to 39.95ft.
 
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It's a WS-1912-IT that I got at Canadian Tire, but I ordered a rain sensor TX32U-IT directly from LaCrosse and it works with the weather station.

I did get a Qual:0 at one point but it didn't link up.
 
Ah yes, that transmitter almost certainly sends a different packet format than the straight Temp/Humidity transmitters that HeaterMeter expects. It is seeing the packets, it just doesn't know how to translate them. If you want, I can take a look at what the data is and there's a chance I can decode it. If you're interested I'll need your heatermeter login information (email bmayland capnbry.net) and for it to remain plugged in near the transmitter for a while.

EDIT: And Qual starts at 0 before any packets are received. If it is working 100% that number should start at 0 then climb to 128 and stay there,
 
email sent.

Thanks for looking into this for me Bryan.

Now I can stop obsessing about it and get my rotodamper wired up :)

Dave!
 
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