I bought a cheapie [wireless rain gauge and temperature sensor from La Crosse Technology. The sensors apparently transmit at 433MHz, and the receiver just displays the info. The more expensive base stations have a PC interface, but I’m guessing that the sensors are the same across the lineup. Which means: I ought to be able to hook up a 433MHz receiver to a serial port and receive the rain/temp data myself, without forking out a lot of money for a fancy receiver and display that I don’t need.
Has anybody played with this stuff? Any idea whether one of the SparkFun receivers (like, particularly [this one) would receive the sensor signals?
I haven’t tried the La Crosse products, but the signal from the Radio Shack units can be picked up with these receivers. I wanted to integrate a few of Radio Shack sensors with the rest of my weather station. The problem with the Radio Shack units is that they use differential Manchester encoding with interleaved 0 bytes along with data values that I haven’t been able to decipher. It wasn’t a simple async serial transmission. I’m wondering if anyone else has tried to integrate either the La Crosse or Radio Shack weather products.
I’d open up the transmitter to see what’s inside. If you can find the digital input to the transmitter, you can see what it’s sending (with a scope, of course).
My guess is that receiver will work but encoding is very likely not async. probably manchester like riden’s. You will need to decipher both the encoding and the protocol. If you can get the receiver showing a waveform, I’d subject the transmitter to some known conditions and see what gets transmitted. without knowing that is being sent (for example the temp), you will have a hard time decoding it.
Philba:
I’d open up the transmitter to see what’s inside. If you can find the digital input to the transmitter, you can see what it’s sending (with a scope, of course).
D'oh, I didn't even think of that. The radio waves must have scrambled my brain; that's the first thing (well, maybe the second or third thing) I'd try if it was a wired system.
Fortunately, I have a scope, and I have reason to believe that the rain gauge sensor transmits a simple integer (the number of times the water buckets have tipped back and forth, possibly only counted since the last transmission). So I have a straightforward, easy-to-manipulate data source. Time to break out the screwdrivers…