![]() ![]() I also made sure every time I pop in the battery I get the same waveform. Following the same procedure as before, pop in the battery, power on the RF sniffing circuit, and launch the Audacity recording software, I got a waveform like the one shown in the image below.Ĭool, this looks a lot better. So let’s see if this rain gauge is easier to tackle. By detecting how many clicks there are within a given time, we know how heavy the rain is. The way this works is quite neat: the seesaw swings left and right, every time the magnet passes by the reed switch, it triggers a click. So where is the magnet? It’s on the bottom of the seesaw. At the center is a reed switch, which is normally open but will close if there is a magnet nearby. Remove some tiny screws, the transmitter circuit is finally revealed. Basically the rain water drains through the bucket hole onto the seesaw, and creates some motion to be detected.Īt the bottom of the assembly is the battery compartment. Underneath the bucket is a plastic seesaw which swings left and right. The outside of the transmitter unit looks like a bucket. It’s probably worth explaining at first how the rain gauge works, because it’s quite a clever design. This time I bought an Acu-Rite 00899 wireless rain gauge. They look nothing alike, even though both were captured right after the batteries are popped in and no rain has been detected.Īfter pulling my hair for a couple of days and finding no clue at all, I decided to give it up and try a different model. Here are two examples of the captured waveforms. Also, the 0/1 bit patterns are completely unclear from the captured waveform - there are at least 4 or 5 different wavelengths. The main problem is that I can’t even register a consistent reading at 0 - every time I pop in the battery, I get a different signal that seems to have nothing to do with the previous readings. ![]() I bought it two years ago and I don’t know if it’s still available now. My first target was an Acu-Rite 00875W rain gauge. There are several different wireless rain sensors on the market. Update: RPi is also supported now! Check the provided programs at the end of this post. Continuing from Part 1 and Part 2, this is the third and last post about how I reverse engineered a few off-the-shelf wireless temperature, humidity, and rain sensors, and used an Arduino to listen to and decode the sensor data. ![]()
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