Topic: 433MHz Receiver and a "generic" weather console

[nincehelser]

I've been doing some research on 433MHz receiver modules, and apparently it's not too hard to hook up an inexpensive receiver module (around $4) to a Raspberry Pi using available interface pins.

So what's to stop someone from using this as a base to collect data from any brand of weather sensor transmitting on 433MHz and feeding that into a weather program? 

There's already some "sniffer" code available, and that could be used as a base to identify and extract the data from the packets.  You could then feed that data into some software like weewx and really make an interesting all-in-one system  (except for the sensors, of course).

So would it really be that straightforward, or is there something critical piece I'm missing? 

[aweatherguy]

Short answer: been there, done that. There is lots of stuff out there about how to build your own receiver for various brands of weather stations.

I've got one put together here that uses an Arduino controller instead of the Pi -- the Pi is kind of overkill for that task unless you want to make a complete console with display and LAN connection -- which would be another fun task.

I've got free designs available at the URL below for the Arduino solution -- which include a simple unit that is not too hard to build for the average hobbyist plus a more advanced design which is also available already built. The web site also has a document on decoding Oregon Scientific packets plus a couple other items. One caveat however -- the designs linked below are specific to one particular weather logging program http://wmrx00.sf.net, so if you don't want to use that logging program then these design won't help you directly but might still provide useful information.

http://www.osengr.org/WxShield/Web/WxShield.html

Hope this helps...

[wxtech]

I started the project titled the Wxtech Dream Machine.  On a topic here:  http://www.wxforum.net/index.php?board=109.0   I used the Acurite 5-n-1 and 3-n-1 integrated multi-sensors.  They are wind, T/H, rain using 433 MHz transmitters.  Acurite provided me with the data stream encoding breakdown.  I don't have permission to share that proprietary information yet.  I got what I wanted working with an Arduino Uno using techniques similar to a chapter in the book "Practical Arduino".  My Dream Machine was intended to be a forum member do-it-yourself project.  It turned out to be too complicated for anyone else who seemed interested.

It's very simple to buy the 5-n-1 with the 01010 console, open the console and find the 433 MHz receiver.  Attach a cable to the common, PON, and data to feed the Arduino.  Nothing to build.  The difficult part is programming the Arduino.

If anyone else has a project similar to the "Dream Machine", feel free to post your project there and create another dream machine for this forum.
Al - Wxtech

[nincehelser]

Thanks for the info, guys!  It might take me some time to digest it all...

I've picked up an Arduino and a 433Mhz shield last week, but I haven't had time to work with them yet.  I've also got an old 1010 console I can cannibalize.

I just wish Acurite were more forthcoming with information.  Every time I ask for any technical information I get turned down.  Another user recently asked about their protocols on their support board and was turned down, too. 

I think there's a lot of interest in their gear, and a lot of potential for the high-school science-fair crowd.  I don't understand why they won't cater to it with a couple of tech notes. 

Seems like it would be good product promotion and good PR.

[wxtech]

Totally opposite view of Acurite.  I have pages of info supplied to me.  I was even offered spare parts.  Acurite has an excellent feedback program where they want to learn what we do with their products.  They also have prizes, gifts for customers who register ownership.
Attached photo shows the 01010 console with a cable attached to the 433 MHz receiver output.  This is a simple data stream input to the microP.  Three wire cable for 2 signals and common.  PON goes high when the data signal is valid.
The 01010 console still works normally as it feeds data to the Arduino.  You don't need to remove the receiver from the console.

[aweatherguy]

Who did you talk to at Accurite? Do you have an e-mail for contact? I'd like to get those documents on RF stream coding...

[wxtech]

Ryan, aka Rhino on this forum.  Send him a personal message.  I can help you with the decoding but I can't provide a copy of the documents because of the 'non-disclosure agreement'.
Be subtle and ask for assistance personally and privately, don't ask them to respond to a forum conversation.

[nincehelser]

Looks like the magic words are "NDA".   

Unfortunately that makes things incompatible with most sorts of open development.

[wxtech]

This is from a previous post in http://www.wxforum.net/index.php?topic=18690.0
WXforum.net > Weather Station Hardware > What Weather Station Should I Buy? > Topic: davis & arduino
I'll repeat it here because it's already been said.
I used the VN1TX 5-IN-1 sensor and the 1010 console.  The 1010 console has a 433 MHz receiver circuit board module which makes it easy to identify the points to tap into VCC, data, POM, and common.  POM is an envelope that goes high during the time the data is valid.
Simply stated, the data stream is 1 byte preamble; 2 bytes for ID; 1 byte for message type; 1byte for data 0; 1 byte for data 1; 1 byte for data 2; 1 byte for data 3; 1 byte for checksum.  Message type 111000 = wind gust, outside temp and humidity.  Message type 110001 = wind gust, wind direction and rain.  Message type byte also has a VN1TX sensor battery indicator bit.
Al