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		Davis Instruments Weather Club January 1999. ====== Here's a quick preview of this month's contents: ====== An Excel-ent API for software sophisticates .... Tips on sending a clear signal with wireless .... A Wireless Monitor mans the trenches of putting green warfare .... One reader wins, another installs .... And a "once in a blue moon" explanation .... Enjoy! ====== Davis: New Excel-ent API in the Programmer's Reference Library ====== The new year rings in new applications in the Programmer's Reference Library (PRL), our free toolkit for software developers. We've just added a powerful modeling and analysis tool to the formidable PRL lineup - the WeatherLink for Excel API! The API enables Microsoft Excel to store, manage, and model data from a Davis weather station. For the non-software-savants amongst us, "API" stands for "Application Programming Interface." The Davis API allows Excel to communicate with the WeatherLink data logger. On top of the raw API technology, we've piggybacked an Excel template that simplifies your control over the interface. You can then create an Excel application - either through macros or Visual Basic for Applications (VBA) - that displays, manipulates, calculates and summarizes your data in whatever way you want, whenever you want, towards whatever purpose you like. You could, for example, develop a pest or degree-days model that simplifies your monitoring, spraying, or irrigation decisions. (A sample degree-days model is included.) The API uses Excel's VBA facilities to set up your weather station, download data from it, and store the data in a worksheet for analysis. You can set the API to update the data automatically at intervals between 15 minutes to 24 hours. Then, after each update, you can set the API to automatically pull the new data into ongoing calculations. To make full use of the API and it's modeling capabilities, you need to have a good working knowledge of Excel's macros and/or VBA. You'll also need either a WeatherLink or GroWeatherLink data logger and be running Microsoft Excel 97. You can download the API, free of charge, at http://davisnet.com/support/weather/software.asp. ====== How To: Send a Clear Signal ====== Our tech support supervisor, Brett, offers advice on positioning wireless sensor arrays: In an open environment, the Davis system may well exceed our specification of 400 feet. As with all wireless devices, however, barriers, distance, and RF (radio frequency) noise can reduce the strength of the signal. When installing your system keep the following three things in mind: 1. Barriers can reflect or degrade the strength of the signal. If you have a choice, keep the number of barriers as low as possible. Barriers are basically walls, ceilings, roofs, trees, entire buildings, etc. Certain materials, such as metal, are even more likely to shield or reflect the radio waves. 2. If you're considering several possible locations for your sensor array, choose the location closest to the display console. 3. RF noise can interfere with the signal. Some devices are meant to emit RF energy (e.g., cordless phones, two-way radios, wireless doorbells, etc.) Other devices have a side effect of emitting RF noise (e.g., computer monitors, microwaves, motors, fans, etc.) If possible, you should position your display console and sensor array away from these devices. When setting up your system, put your display console in the beeping, or test, mode (see manual). In this mode the station will beep each time it receives a packet of data (every 2.5 seconds). As you locate both your display console and sensor array, you can listen to this beep and determine if the current location is optimal. Having said all this, it's quite likely that you'll be able to set up your system with no problems whatsoever. If your environment does present a problem, the hints above should suffice to get you up and running. ===== Cool Applications: Manning the trenches of putting green warfare ===== Extra! Extra! Extra! News for disease model researchers, rye grass growers, and, um, recreational golfers! This month's cool application comes to us from Albany, Oregon, where one of our new Wireless Weather Monitors has joined a research brigade bent on minimizing the incidence of rust in ryegrass. You've probably seen, even stepped on, this hapless victim - it blankets putting greens the world over. The Wireless station belongs to Mr. Terry Plagmann, a ryegrass grower and vineyard owner in Willamette Valley, Oregon. Terry says he bought the station for his own monitoring use, but that it quickly drew the attention of a USDA research team. The USDA National Forage Seed Production Research Center (NFSPRC) at Oregon State University, led by Dr. Bill Pfender, leapt at the chance to test out their disease model for perennial ryegrass rust. Dr. Pfender's team is looking for grass growers who can help test the disease model in real life conditions. There are three conditions that must be met simultaneously in order for rust to develop: the humidity needs to be above 98%, the temperature must lie between 39(F and 69(F, and the time of day needs to be somewhere between 6 p.m. and 6 a.m. Terry's Wireless Station will monitor these conditions at his field and report back to the folks at the NFSPRC. Thanks, Terry, for sharing this report from the trenches of rust-warfare! We'll keep in touch in the months to come for any updates. For more information about the perennial grass rust research, check out the NFSPRC's site at http://pwa.ars.usda.gov/nfsprc/azevedo/azevedo.htm. And if you're currently involved in - or would like to be involved in - disease model research using your weather station, drop us a line! === Talk Back - One club member wins by replying, another by installing! ==== Hearty congratulations go to Chris Anfossi of Picton, Ontario! Chris was selected randomly from the over 900 respondents who filled out last month's online survey. Chris, your $65 gift certificate should be chugging its way through Montana right about now. Thanks to all of you who participated; the response was phenomenal and your input invaluable! Now for a club member's story - Jay Neale writes: >We live in Afton, Virginia, on top of the Blue Ridge Mountains. Folks are always asking me what the weather's like up here, so this spring I bought and installed a Weather Monitor II. We love it! Now we can quantify all kinds of weather data. >The installation instructions suggested mounting the anemometer on the TV antenna mast. But since we have an antenna rotor, the wind direction would get all screwed up. Also, my antenna is strapped to my chimney and I really didn't want all the woodstove smoke wafting over the equipment - so here's my solution: I went about halfway down the ridgeline and ran 2" PVC pipe through a roof flange. The pipe is bolted to rafters in the attic. >OK, so I'm bragging a bit, but I thought if anyone could appreciate this, you folks would. Thanks, Jay, brag away! And, yes, we do appreciate your solution. ====== Miscellany of the Moment: Blue Moons ====== As some of you may know already, the next three months will feature two, one-night-only, blue moon extravaganzas. The first will arrive on January 31st, and the second, March 31st. This got us wondering what exactly blue moons are, why they come and when, and how often is "once in a blue moon" anyway. Though there's not the time nor space to delve into it here, here's a link to one researcher's surprising findings that span over 400 years and 6 different meanings: http://web.physics.twsu.edu/lapo/EMS/blumoon.htm. ====== That's it for January's E-news! See you next month! The Davis Weather Club E-newsletter mailto:news@davisnet.com