Weather Meter Kit

I interfaced these wind and rain sensors to an Arduino. The sensors are actually just simple magnetic switches. The anemometer has a magnetic reed switch that closes every time it rotates around one time, and it has "somewhat" of a linear ratio of wind speed, to # of rotations per second. The wind vane uses multiple magnetic reed switches to create a resistor based voltage divider to generate different voltages for the 8 wind directions. Most of the time, you will only get directions for N, NE, E, SE, S, SW, W, and NE, but sometimes you can get 2 switches to close and get the inbetween directions of ESE, WSW, ENE, etc... not every unit seems to do this, and you cannot reliably get all 16 directions, so when programming, assume you're only going to get the 8 cardinal directions. The rain gauge is also another simple switch. Every time the measuring bucket inside the gauge tips, the switch will close/open. Every tip / switch change equals .011" of rain. Just count the number of switch toggles and you get rain fall. You can measure the time between tips to get the rate of rainfall in inches/hour. The 3 sensors are all made of plastic as are the supporting arms. The metal pole and screws used to attach the sensors seem like stainless steel. The sensors use RJ11 (telephone jack) connectors to connect. The wire from the sensors doesn't seem like anything weather resistant, so I an concerned that long term UV exposure will damage them in the long term, but right now I am just speculating. I got all of mine hooked up to an Arduino Nano and they work well for now.

So far the kit has been good, from what I can tell somewhat accurate result though I'm still in the building phase of my weather station. I do have one caveat though. If you are using this kit with SparkFun's weather shield, you will need to edit their source file of the "Weather Meter Kit" library. Specifically the SparkFun_Weather_Meter_Kit_Arduino_Library.cpp file. There is a comment about the shield using a different circuit therefore the values are different. I was getting wildly inaccurate wind direction readings and thought it was defective. Going to their sight and finding the weather meter station data sheet, I was able to confirm all of the readings of the resistance by direction were accurate. That meant the problem was either code or on the shield. Turns out a bit of both. In the referenced file I commented out these lines: // _calibrationParams.vaneADCValues[WMK_ANGLE_0_0] = 3143; // _calibrationParams.vaneADCValues[WMK_ANGLE_22_5] = 1624; // _calibrationParams.vaneADCValues[WMK_ANGLE_45_0] = 1845; // _calibrationParams.vaneADCValues[WMK_ANGLE_67_5] = 335; // _calibrationParams.vaneADCValues[WMK_ANGLE_90_0] = 372; // _calibrationParams.vaneADCValues[WMK_ANGLE_112_5] = 264; // _calibrationParams.vaneADCValues[WMK_ANGLE_135_0] = 738; // _calibrationParams.vaneADCValues[WMK_ANGLE_157_5] = 506; // _calibrationParams.vaneADCValues[WMK_ANGLE_180_0] = 1149; // _calibrationParams.vaneADCValues[WMK_ANGLE_202_5] = 979; // _calibrationParams.vaneADCValues[WMK_ANGLE_225_0] = 2520; // _calibrationParams.vaneADCValues[WMK_ANGLE_247_5] = 2397; // _calibrationParams.vaneADCValues[WMK_ANGLE_270_0] = 3780; // _calibrationParams.vaneADCValues[WMK_ANGLE_292_5] = 3309; // _calibrationParams.vaneADCValues[WMK_ANGLE_315_0] = 3548; // _calibrationParams.vaneADCValues[WMK_ANGLE_337_5] = 2810; and uncommented the similar lines immediately below them. Now the wind direction is accurate.

I had an Ambient Weather model 2080 whose anemometer had quit registering on the base station, so I ordered SparkFun's weather meter kit. It was a perfect match for the Ambient Weather pieces. All I had to do was plug it into the power source/transmitter in the thermometer/humidity part for it to work. Here's a workaround for the only drawback I found, which was that with an additional length of pipe to work with, there was no way to keep the top pipe from twisting on the bottom pipe, which changed the reported wind direction. The SparkFun kit came with no instructions, so here's what to do: the arm which holds the rain gauge piece has a collar to hold it on the pipe, with two screws on top and two on the bottom. Secure the top two screws on the top pipe and the bottom two screws on the bottom pipe, with the seam between the pipes in between. This will prevent the top pipe from twisting and changing the reported wind direction.

Wind vane died in under 2 years. They don't sell replacement parts, you have to buy an entire new kit to fix one failed piece. It is fairly inexpensive, but having to replace failed parts (and buying an entire new kit) diminishes the value. If you're looking for a science experiment then it might be worth it, if your looking for a weather station then you might want something different. Update: the anemometer bearing has now gone bad a couple of months after the wind vane failed. Still under 2 years old. I may have to purchase another kit since I don't have time to rework the weather station and then hope the replacement will last another 18 months.

I am so happy with this kit! I was beside myself looking for replacement wind cups for my beloved weather station after severe wind gusts blew it off the unit & 2 cups broke off. After 2 weeks of trying all kinds of strong glues to repair it, none could stand up to the heat of the desert. Finally, I found this and took a chance. Easy set up...plug and play to my existing transmitter. Plus it comes with its own poles, which I used as an extension to what I have. As a result I have better accuracy all around. A definite upgrade for me without the cost of the electronics.