Introduction

Last Christmas, I recieved a LaCrosse WS-2350 weather station. This pages reports some of the experiences I had while trying to tease some decent data out of it.

The hardware

The hardware comes in several parts. The first is a LCD base station which shows various readings and also has an indoor thermometer and humidity sensor as well as a barometer. This can be linked to a PC to read the data. The outdoor assembly consists of a control unit which has a thermometer and humidity sensor. It also has a combined wind vain and anemometer as well as a rain gague, both of which are connected by cable to the control unit. The control unit can either be cabled to the base station or link by a 433MHz wireless link.

The hardware has a number of short comings. Most notably is the unreliability of the wireless link. The base station can loose connection to the controller for hours at a time and then reeastablish connection several times a day. It is also know to go through several sessions of losing connectivity, getting it back, then losing it again. There are a number of mods on the internet to improve the wireless by installing a better antenna in the base station or controller, although most people tend to abandon this in favour of using a wired connection. In addition to this, LaCrosse's engineers also neglected a few things, like actually installing any filtering on the connections from the wind and rain sensors. The weather station is known to give outragious readings at times, such as high and low wind readings. Apparently there is also phantom rain when people are operating radio transmitters. Again, there are some people on the Internet who have modified the station by replacing the rather crap Cat3 cables and adding Cat5 with ferrite rings.

There are a number of other mods on the Internet and these include

  • Increasing the surface area of the rain sensor to increase precision
  • Adding a heater to the rain sensor to stop it getting blocked by snow and ice
  • Modifing the controller to send data more frequently to the base station when using wireless
  • PC interface

    The base station has a RJ11 socket and connects to the PC via a DB9 serial connection. It also comes with a USB to serial adapter that has an intergrated Prolific PL2303 USB to serial converter. Here's where the cleverness ends. It then uses some propritory protocol to talk to the weather station. The system comes with some software for Windows. Linux users might be interested in Open2300 which is an Open Source tool for gathering data from the weather station. It can output in a dump format, to a SQL database or submit to a number of ameature weather sites.

    Placing the weather station

    We have a brick BBQ at the bottom of the garden that has fallen into disrepair. It has two 6' poles, one on either side. After a trip to the local B&Q, I bought a couple of fence post holders and a plank of wood. I painted the wood with wood preserver and bolted the fence post holders onto the plank. This created a nice shelf above the BBQ onto which I was able to mount the weather sensors. After a couple of weeks, the local kids managed to kick a football at it and distroy the anemometer holding, so I had to fashion a new one out of a piece of wood.

    The current set up has a couple of shortcomings. Firstly, it is more sheltered than I had envisaged and doesn't give the best wind readings. Second, due to the failure of the wireless link, it often loses connection to the base station. I am currently researching attaching the anemometer to a TV aerial pole and sticking it above the roof line. Something of a challenge on a three storey building!

    Collecting the data

    Every five minutes, I run a cron job that runs the Open2300 dump command and pipes the output into a PERL script that I wrote. This write the data both to a MySQL database and to some RRDtool round-robin databases. I created by own MySQL database rather than using the Open2300 tools, as it gives me more flexability over the data. I also used RRDtool as this is ideal for graphing. I could probably have used one or the other but it was easlier (read lazier) to do it this way. I have some web pages here that show the current weather. I am also working on some pages to show historical data and graphs.