I’m hoping people can give me some help with leveraging the wireless sensor from an Acu-Rite weather station. I have a 5-in-1 outdoor sensor that transmits to a display console and an ethernet connected “Acu-Link” Internet bridge. The Acu-Link sends the sensor data to a proprietary web service for display in a browser, iOS app, or forwarding to Weather Underground. I’d like to get a serial data stream from the sensor myself so I can munge the data and I can send updates to WUnderground more frequently and participate in additional community weather station networks.
I cracked open the LCD display console and the Acu-Link bridge to [see what was inside. I found that both units had a small peripheral PCB that has a MICRF211AYQS 1226 chip, which I’ve identified as a [433 MHz (nominal) RF receiver from Micrel. As best as I can understand, this provides a demodulated signal output that then has to be further decoded to recover the data payload.
So my question is, where should I go from here? I’m starting with a soldering iron, some basic tools, and a generic multimeter and very rudimentary knowledge of electronics (most of my practical technical knowledge is layers 3-7 of the OSI reference model). My hope was that I could invest less than $50 in parts for some sort of *duino and an RF module to get to the point where I have a serial data stream. I don’t have a big budget for instrumentation at this point, but I’d be happy to spend another $50-100 on stuff that I can reuse as I tackle some future projects (home energy monitoring, an LED light project).
Is there a a Sparkfun RF receiver with these, or is there something else I should look for? What else should I know (and where should I look)?
You will need to figure out how to decode the signal from the receiver, then you can do anything you want with it. All manufacturers of remote weather station sensors seem to use a different protocol but many have already been decoded. See this example: https://github.com/kayno/ThermorWeather … therRx.pde
There is usually some extra data in the bit stream, like battery status and error checking. Some progress has been made for Acu-Rite, see this thread: http://arduino.cc/forum/index.php?topic=112699.0
Just about any cheap 433 MHz receiver module will work; you can get them at SFE for $5.00 or salvage them from discarded weather station receivers (I found a couple at a thrift shop).
Thanks for the advice, and particularly the link to the people who have been working to work with the acu-rite data on an arduino. I missed that in earlier searches, though it looks like it may be for an older device that, for whatever reason, isn’t compatible with the sensors and receivers I’m using. Still, it is probably a good starting point.
This might be a more ambitious first-project than I anticipated, but I’ll probably pop for an RX and an arduino and see what I can get with a weekends work. If necessary, I should be able to use DNS hijacking to get at [the data the acu-link bridge is pushing up to the web service when it comes time to interpret the sensor values from the decoded bitstream.
As you may have already seen, Audacity is a great help in decoding these sensors. All you need to do is hook up the 433 MHz receiver with a resistive voltage divider and send the output to your PC audio input. Here is an example of a more recent attack on the Acu-Rite RF protocol. http://arduino.cc/forum/index.php?topic=145341.0