Posted tagged ‘WMR200’

Weather Station Winter Report

November 21, 2014

The onset of Meteorological Winter is a little over a week away here in New Jersey (it runs from 1st Dec to 1st March). Last year’s winter here represented a period of prolonged cold and quite sizeable snow fall. It was certainly more severe than anything my weather station setup experienced in the preceding years in Scotland (although note that the station was only installed there in August 2011 after the severe winters of 2009 – 2010 and 2010 – 2011).

This post relates my experiences with my weather station from last year’s winter (2013 – 2014) and is a record of what worked well and what did not work so well. I run a standard Oregon Scientific WMR200 setup and will describe how well each of the sensors stood up to the harsher than normal conditions. I have illustrated the post with pictures taken at the time and supplemented with various charts produced using my Meteo Sheeva setup.

Winter 2013 – 2014 in New Jersey

Last winter New Jersey, like many parts of the USA, was in the grip of a prolonged Polar Vortex. There were certainly colder places in the USA that winter. There were also places that got a lot more snow. Indeed, according to meteorological records, New Jersey has itself had much colder and more snowbound winters in its past. What made it unusual was how prolonged the cold was and, as a result, just how long the deep snow was able to persist.

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As I have already mentioned it was very cold. The coldest it got according to my instruments was -15.7°C on the morning of 7th January 2014. What was really extreme was that the temperature could remain entirely below freezing for days at a time. The chart below shows the number days per month from December 2013 to February 2014 when the temperature did not rise above 0°C. January was especially gruelling with 14 of 31 days spent entirely below zero.

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The following chart shows the minimum temperature for every day from the start of December 2013 through to the end of February 2014. Extended cold like this quickly becomes wearing on people and machines alike.

dec - feb min temperature

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Note the spike in minimum temperature on 22nd December 2013 (to 13.7°C). This is not a sensor anomaly and I remember that day well. Preceded by some rather cold days the temperature got up to 20.6°C. This made for shorts and t-shirt weather for one day in December. As we can see from the chart the warm weather did not last long and temperatures plummeted and stayed cold thereafter.

Then there was the wind chill. This dropped to a low of -21.3°C on the same morning as the lowest temperature was recorded. I suspect that the wind chill was worse than this in reality as my anemometer is not in the most exposed of locations. The graph below shows the daily minimum wind chill from late December 2013 (when the sensor was installed) through to the end of February 2014.

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Finally there was the snow. Up to 2 feet was present on the ground for weeks at a time. The problem was not that it snowed an incredible amount. Instead what did fall remained for weeks at a time because of the consistently low temperatures.

snow depth

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Weather Station Sensor Location

The siting of my weather station’s sensors has some bearing on my experiences last winter so I will describe that briefly here.

I am not entirely happy with my weather station setup at the moment. Unlike my previous setup in Scotland I am constrained in terms of space having no garden or roof to speak of. The anemometer/wind vane and rain gauge are installed fairly low down on the makeshift box and pole arrangement pictured below (a UV sensor is also pictured but this was not actually installed until mid-2014). The Temperature/Humidity sensor is better situated and can be found round the corner on another pole in a spot well sheltered from the sun.

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Before I turn to each sensor’s winter performance I will talk a little about batteries. Oregon’s various sensors are wireless and are therefore powered by AA or AAA batteries. Conventional wisdom in weather station circles goes that it is best to swap from alkaline over to lithium batteries when it gets cold as they perform better in such conditions. I stuck it out with normal alkaline batteries last winter and suffered no signal drop-outs from my sensors. Lithium based batteries are no doubt better for extremely cold conditions but they are an unnecessary expense for the kinds of conditions I saw last winter.

Temperature/Humidity Sensor

The WMR200 comes complete with a THGN801 temperature and humidity sensor. The sensor is a relatively small box installed within a plastic weather shield. Mine is mounted on a pole about a metre off the ground. During the winter the shield did its job well as it became heavily encrusted with ice and protected the sensor which kept reporting consistently with no signal drop-outs throughout the winter. The shield even sported a 30cm icicle at times as pictured below.

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Ice was a real hazard generally last winter. Indeed the accumulated ice managed to bow the previously vertical trees near the sensor to be almost horizontal under its weight.

winter weather

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The only let down with the THGN801 was a strange behavior that manifested whenever the air temperature dropped to -10°C. Whenever this occurred the humidity would continue to be reported by the sensor but would not vary until the temperature rose above -10°C at which point it would start to report the true value again.The following chart shows this behavior starting at just after midnight on the 7th of January and persisting until mid-morning on the 8th of January (where the blue plot goes flat).

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Basically the humidity reported by the THGN801 below -10°C will almost certainly be incorrect and as will the associated dew point. Various weather forum searches have informed me (for example, here) that this is not an individual sensor fault but an endemic problem with the THGN801 and other similar sensors . If I lived in an area with frequent -10°C cold I would not be relying on Oregon gear.

Anemometer / Wind Vane

The WGR800 is a combined anemometer and wind vane. Mine is mounted, less than ideally, on a relatively short pole. The sensor performed well with no signal drop-outs all winter. The only issue I had with it was with the wind vane component on top and I put this at least partly down to its low position. When heavy snow fell on it overnight it could become encrusted on the vane which froze and locked into a single fixed position. Pictured below is one occurrence of this (note the rain sensor is starting to disappear beneath the snow. More on this below).

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While frozen the wind vane reported a constant (and incorrect) wind direction until it defrosted sufficiently to move again. This wind vane would typically only be frozen for a few overnight hours at a time when there was heavy snowfall. One such instance is charted below when there was wind but a suspiciously constant South-Easterly wind.

wind vane frozen 25 jan

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Rain Gauge

The final outdoor sensor I had last winter was the PCR800 rain gauge. There is not much to say here as it was completely buried under deep snow for much of last winter as pictured below. Once it was buried I felt it was safer (for it and for me) to leave it there insulated under the snow until it was revealed in the thaw. Despite its imprisonment it reported (understandably zero rainfall) constantly with no signal drop-outs throughout the winter.

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Winter 2014 – 2015 in New Jersey

My setup remains the same as it did last winter apart from the addition of a UVN800 UV sensor. Customer reviews show this to be a particularly delicate sensor prone to permanent failure in colder conditions. Given that temperatures here are already falling frequently below zero and UV is already a distant summer memory I have already mothballed the sensor until spring comes around.

The rain sensor did fail the following May when it was hit by 11.5 cm/hr rain. As a result its innards got a bit wet and no amount of drying could get it to signal consistently again thereafter. I have since replaced it with a spare unit. The question is, did its icy incarceration shorten its time span? I will never know but if my replacement rain gauge starts to become entombed in the same way this winter I will fish it out and bring it inside. There is no point in risking it in conditions where there is no rain to report anyway.

With a week to go and temperatures already plummeting here I have prepared all of the deployed sensors with new batteries. All that remains now is to see what this winter will bring to my corner of New Jersey.

UVN800 Wireless Remote Sensor Review

April 13, 2014

Until recently I lived in Scotland where UV is hardly ever an issue given the hideous weather we tend to get there. However, I now live in New Jersey in the USA where the summers can be very hot and the risks of UV exposure are more of a concern for me. Given that I took my weather station with me when I relocated (which comprises of both the WMR88 and WMR200 base stations) it made sense to consider expanding its capability to record UV.

One of the advantages of Oregon Scientific’s range of wireless weather stations is the ability to add extra sensors. I have, for example, previously taken advantage of this by adding an additional temperature and humidity sensor in the form of a THGR810 unit.

Both of my base stations also support a UV sensor in the form of the UVN800. This sensor is not normally bundled with the WMR88 or WMR200 but I purchased one recently as an add-on. The unit normally retails for $59.99 but I was able to pick it up for $43.79 from Amazon (not including sales tax). Both the full and discounted prices are on par with what I would expect to pay for other additional sensors such as the THGR810 mentioned above. It arrived undamaged and well packaged in a relatively small box:

UVN800 boxed

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Upon unboxing I was presented with the UVN800 unit itself, a wall mount with two screws, a ground spike, AA batteries and instructions.

UVN800 unboxed

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This provided me with two different installation options. Either use the ground spike to insert the sensor in the ground or the wall mount and screws to attach it to a wall or pole. I chose the wall mount option which I attached to my existing sensor pole. However, I appreciate the flexibility of the ground spike option. The trick with the UVN800 is to orient it such that the UV sensor on top of it has a constant, uninterrupted view of the sky which I could more easily achieve with the pole mounting.

UVN800 mounted

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Installation of the UVN800 is fairly straight forward if a little more awkward than it could be due to some weird choices made by the unit’s designers. First of all accessing the battery compartment requires the removal of four small screws from the base of the unit to access the battery compartment. Why the compartment is not accessed by a sliding mechanism like most of Oregon’s sensors is a mystery.

Secondly the wall mount is screwed into place at the bottom of the unit obscuring the battery compartment and reset button. Given my pole mounted configuration changing batteries will be far more time-consuming than it should be. I will have to unscrew the wall mount from the pole, detach the sensor from the wall mount, remove the screws from the battery compartment. Only then can I change the batteries and will then have to reverse the procedure to reinstall the unit.

So far this is my only gripe with the UVN800 and it is not a deal breaker by any means. One the batteries were installed pairing it with my base stations was as simple as hitting the sensor’s reset button and initiating a search from each base station. They both started displaying UV Index readings straight away. On both the WMR88 and WMR200 this takes the form of a live UV Index display and a graph of the last 10 hours of values.

Having UV Index values displayed on my base stations was just the start, however. I publish weather data to my own website and wanted to add UV Index information to it. I use a Meteo Sheeva connected to my WMR200 as a data logger and to do uploads of weather readings and graphs to my website. As expected it was a snap to get it to start logging data from the UVN800. As an example here is one of several graphs I have configured on the Meteo Sheeva which display the last 7 days of maximum UV Index values:


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My Meteo Sheeva also uploads data in WD Live’s clientraw.txt format which includes UV Index readings. I have rearranged my existing WD Live console on my website to incorporate a UV Index bar:


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Returning to the UVN800 itself there is one more thing to note. The reviews on Amazon for the UVN800 indicate that many units permanently fail just after a year of operation. At the time of writing I have only been operating the sensor for a few days but will add a note to this review if and when it fails.

Should the sensor last at least a couple of years (as all my other sensors have already done) then I would not hesitate to recommend the UVN800 as a useful, easy to use addition to an existing Oregon Scientific wireless station.

Meteo Sheeva

November 23, 2013

Late last year I purchased a Meteo Sheeva to log the data from my WMR200 weather station. While the WMR200 is supposed to function as a simple data logger Oregon Scientific’s awful software renders the feature useless. Therefore, to log data from the WMR200, I required a separate connected computer. My requirements for a data logging machine were that it be:

  • capable of logging the data from my WMR200’s sensors
  • able to publish my  weather data live to the internet
  • compact
  • low-cost
  • turn-key

The Meteo Sheeva fulfills all of these requirements and then some.

A Meteo Sheeva is actually a combination of two things. Firstly there is the “Sheeva” part. This takes the physical form of a SheevaPlug Linux-based compact computer. Secondly there is the “Meteo” part. The Meteo Sheeva ships with an SD Card preloaded with a demo version of the Linux-based MeteoHub data logger software. I purchased the Meteo Sheeva unit from a UK vendor called New IT for £130 and licensed the MeteoHub software from Smartbedded for £50.

For me this is a relatively low price purchase compared to dedicating a full size machine to data collection. I could have created a data logger for less money by configuring a Raspberry Pi with, say, wview. However, I was more interested in my particular solution being turn-key in nature than in saving more money.

The SheevaPlug fufills the compact requirement as it measure only 11 x 7 x 5 cm. This makes it bigger than a cased Raspberry Pi but still small enough to tuck out of sight. This picture shows my SheevaPlug next to a beer mat for comparison purposes.

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Like the Raspberry Pi the SheevaPlug runs off of a SD Card. It is powered off the mains via a detachable radio type power cable. For connectivity it has a USB socket to connect to a weather station and has an ethernet port for networking.

The unit’s setup is indeed turn-key and couldn’t be much easier. I simply connected the SheevaPlug to the mains, attached it via USB to the WMR200 and to my router using an ethernet cable. Once powered up all interactions with the MeteoHub software are made via a web browser and a simple web-based UI. All I had to do to start data logging was access the Weather Station section of the UI, specify that a WMR200 was connected and then select which of the automatically detected sensors I wanted to log data from.

The MeteoHub interface is simple, uncluttered and well organised. For example, here is Sensors page which shows the current status of all connected weather sensors:

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The MeteoHub manual is excellent. The manual covers every detail of the software’s capabilities. This is invaluable, not because the MeteoHub software is difficult to use, but because of the massive amount of functionality it provides. I will describe a small subset of the main features which I have found to be the most useful for my own requirements. Bear in mind that MeteoHub is capable of much more than I make use of.

The first feature I started experimenting with was the ability to specify charts from the logged sensor data. I focused on bar and line charts but there are many more options available as well as flexible configurations for time period, aggregation buckets, scales and colours. With limited UI-based configuration I was able to create charts for all of my weather data types over many different time periods.

Here are a selection of some of the charts I have specified for my own setup:

Last Day of Maximum Wind Speed, Gust Speed and Wind Direction:

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Last Day of Temperature, Humidity and Dew Point:

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Last Month of Daily Surface Pressure Ranges:

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Last Month of Daily Maximum Wind and Gust Speeds:

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Last Year of Total Monthly Rainfall (data logging started in September):

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Any of the charts can be displayed via the MeteoHub UI at any time. However, the charting feature really come into its own when combined with the automated FTP upload feature. This can be used to publish updated charts to a website on a pre-defined schedule. I use this feature to publish my setup’s charts to my own weather website.

MeteoHub can also automatically publish its data via FTP in WD-Live format. This makes it capable of feeding the Flash-based Weather Display Live dashboard. This is separate software from another vendor but costs only $40 and enables a dynamic and attractive looking weather dashboard which is highly configurable. This is my particular online weather dashboard:

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Weather data can also be pushed to more than two dozen online weather services including WeatherBug, Weather Underground and the UK Met Office. For example, here is my data displayed on the Met Office’s WOW website:

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Publishing my weather station’s data to my website in WD-Live format had an interesting side benefit as I could use it to view my weather station’s latest readings from my smart phone. The paid-for but inexpensive Android Weather Watch Widget can be pointed at the WD-Live data file’s location and display the latest conditions for my weather station:

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In short I cannot recommend the Meteo Sheeva highly enough as a weather station data logger. Even though I only take advantage of a subset of its capabilities the features I do use make use of make it more than worth the money I have invested in it. You can get a cheaper and smaller solution using a Raspberry Pi. However, if you want something that works out of the box then the Meteo Sheeva cannot be beat.

WMR200 Weather Station

December 28, 2012

Towards the end of last year I wrote a three part post about my new Oregon Scientific WMR88 weather station (part 1part 2part 3). While the installation was successful the setup was not completely reliable. I concluded the final post stating:

“If I am serious about logging and publishing my weather station’s data I will have to invest in some better kit to minimise gaps in the data. I have my eye on the WMR200 and may purchase one next year. The WMR200 has a built in data logger and a hefty looking external antenna which unlike the WMR88′s internal antenna I can, if necessary, modify. Also it should be possible to use the same suite of sensors simultaneously for the WMR200 and my existing WMR88 base station. This means that I can have two operational weather consoles and a set of spare sensors.”

Six months ago I did exactly that and purchased an Oregon Scientific WMR200. The idea was to compliment, rather than replace, my existing setup. This post details my experiences with this new weather station. Note that in this post I tend to compare the WMR200 with the WMR88 so you may want to read my original posts on that first.


The WMR200 currently retails for £400. However, Amazon, Weather Shop UK and Oregon Scientific themselves tend to offer the unit at up to £120 cheaper from time to time. It pays to be patient and wait for such a deal rather than pay full whack. I ordered directly from Oregon as they had the cheapest price at the time.


When the WMR200 arrived the most striking thing about it was how much bigger it was boxed than the WMR88:

wmr200 boxed

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Then again you get a lot more with the WMR200 to help justify the extra cost. Pictured below are most of the package’s contents:

  • PCR800 Rain Gauge with rain filter
  • THGN801 Temperature and Humidity Sensor
  • WGR800 Wind Sensor (Anemometer & Wind Vane)
  • STC800 Solar Panel
  • USB Cable for connecting the base station to a PC
  • Batteries for all sensors and the base station
  • A mounting pole in three sections, base, rope, fasteners and stakes for ground mounting
  • Cable ties
  • Various brackets U-bolts and screws to allow for other mounting options
wmr200 unboxed 1

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The remaining contents are the WMR200 base station itself and its power adapter which are shown below:

wmr200 unboxed 2

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The included kit allows for a lot of flexibility as to how the sensors are installed, more so than the cheaper WMR88. All sensors bar the rain sensor can be placed together in a single array using either the supplied pole or an pre-existing one. Alternatively sensors can be distributed across separate locations using the supplied brackets. For example, attached to fences or buildings. The supplied pole which, in combination with the supplied ropes, fasteners and stakes allow for the option of a ground mounting which  gives substantial height to the sensors.

Sensor Installation

I had already installed a mounting pole for the WMR88’s wind sensor so used it and the supplied brackets to install the wind sensor (pictured top), solar panel (pictured bottom right) and temperature/humidity sensor (pictured bottom left) together in the same location:

wmr200 sensors

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The WGR800 wind sensor supplied with the WMR200 is the same as the one that comes with the WMR88. The curious thing is that the WMR88 manual states that its wind sensor transmits a signal every 56 seconds while the WMR200 manual says signal transmission occurs every 14 seconds. Certainly each station updates their displayed wind readings at the stated intervals. Clearly the longer display interval on the WMR88 base station is a limitation of the base station rather than the wind sensor which transmits more frequently.

The THGN801 temperature/humidity sensor that comes with the WMR200 is shielded unlike the THGN800 that came with the WMR88 (I had built a shielded housing for the THGN800 which I can now decommission). While the THGN800 had clearly been superseded it was not completely obsolete. I simply changed its broadcast channel from 1 to 3 and moved it into a room in the house so I could see readings from there (as detailed here I had already installed a THGR810 sensor on channel 2).

The STC800 solar panel is a nice addition as it helps to power the WGR800 and THGN801 and will hopefully save on replacement batteries. It has two cables attached to it which can be plugged into each of the aforementioned sensors. The connections look to be well insulated and the supplied cable ties can be used to attach the power cables firmly to the sensor brackets.

I had no cause to replace or move the existing rain gauge as the same rain sensor is supplied with the WMR88 and WMR200: the PCR800. The bonus with the WMR200 is that you get a rain filter in the form of a fine metal grille to place in the gauge to catch debris. I have placed this in my existing PCR800. See my previous post for details of the PCR800’s mounting on the side of my shed.

In summary my current sensor setup now comprises:

  • THGN801 for outside temperature/humidity
  • WGR800 anemometer & wind vane
  • STC800 solar panel to help power the THGN810 and WGR800
  • PCR800 rain gauge
  • THGR810 for temperature/humidity in the garage
  • THGN800 for temperature/humidity in the house (placed in a different room from either base station to compliment their readings)

All of the sensors now in place are compatible with both the WMR88 and WMR200 base stations. As the sensors simply broadcast both base stations can receive data from all of the sensors.

This hybrid setup has also provided me with unused backup sensors for both wind (WGR800) and rain (PCR800). Given the extortionate cost of replacement sensors these are handy items to have in case of failure in one of the original sensors.

Base Station Installation

The WMR200 base station is a super-charged version of the WMR88 capable of doing everything the cheaper unit can do and more. First I will cover the similarities between the two before looking at the differences.

Like the WMR88 the WMR200 functions as an internal temperature and humidity sensor and as an air pressure sensor. The WMR200 has an optionally backlit LCD display similar to the WMR88. The WMR200 also features the same clock synchronisation feature as the WMR88. Both units can be powered from the mains and be loaded with backup batteries.

The WMR200 displays the same information as the WMR88 (temperature, dew point, humidity, wind, rain, pressure, UV, historical highs and lows, forecast, moon phase and current time) but its larger screen means that it can display more of this information at the same time. For example, the WMR88 can only display one set of temperature and humidity readings at a time while the WMR200 can display the internal base station readings and the readings from a selected channel simultaneously. The WMR200 can also display rain, UV and atmospheric pressure readings at the same time while with the WMR88 you have to cycle between the values. This makes it possible to review the current conditions at a single glance.

The WMR200’s screen features a resistive touch screen rather than the physical buttons of the WMR88. This makes the operations of cycling between sensors, checking highs and lows, etc far more intuitive. Unfortunately the WMR200 has preserved the WMR88’s annoying feature of beeping whenever the touch screen is pressed. This again cannot be switched off.

The WMR200 also functions as a data logger. However, Oregon Scientific’s included software remains as useless as ever so accessing the stored data is nigh on impossible. This is not an issue for me as I now use an external data logger connected via USB (more on that in a future post).

The WMR200 supports up to 10 channels and therefore up to that number of temperature/humidity sensors while WMR88 only supports 3 channels.

Below is a picture of the base station mounted to a wall (easily accomplished as there are mount points on the back):

wmr200 base station

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The final advantage of the WMR200 over the WMR88 is the external antenna. Oregon Scientific’s wireless weather stations are famously awful at reliably picking up remote sensors. I did not expect a great improvement with the WMR200’s rather tiny antenna but at least it gave me scope to apply simple modifications to improve performance which I could not hope to accomplish with the WMR88’s internal antenna.

So is the WMR200’s external antenna more reliable than the WMR88’s internal antenna? That is difficult to say. What I can say is that it is far from perfect. My first site for the WMR200 was less than 10 meters from all sensors with an internal wall and brick wall inbetween. This location gave intermittent signal issues. A complicating factor was that this location was also my office and contains my laptop and router. I suspect that these may have been responsible for some interference with the signal.

After a few weeks of experimenting I had moved the base station into the upstairs hall which gave it almost line of sight to the sensors via a window. This took the interior wall out the equation and eliminated any interference from electronic devices. The new location experienced less signal drop-outs but did not cure them completely. I then implemented a simple modification by attaching a metal radio aerial to the existing antenna using a bulldog clip:

wmr200 base station with antenna long

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Since the base station move and my simple modification I have experienced minimal signal drop outs. Specifically, a few weeks apart and lasting no more than 5 minutes. This is more than acceptable for my purposes. Getting the best from the WMR200 appears to be a combination of closest location to sensors, line of sight to sensors or minimal obstacles, minimal electronic interference and putting more metal in the air.

I have attached my data logger via the supplied USB cable to the WMR200 through the wall. The WMR88 has been relocated to the living room downstairs for display purposes. Handily this means that I can now check the current conditions without changing floor.

On the subject of the data logger I have installed a SheevaPlug running Meteohub weather server software. I will detail my experiences with the data logger in an upcoming post. For now it will suffice to say the SheevaPlug/Meteohub combo is a nice piece of kit that is easy to set up and is feature packed.

Summing Up

I am happy with the WMR200 now that I have it working reliably. The antenna issues make it far from plug and play and any prospective buyers should be prepared to put a lot of effort into minimising signal drop outs. In hindsight I would have bought a WMR200 in the first place rather than the more basic WMR88. On the other hand, I find the flexibility of having two base stations to be the perfect setup and an advantage of having a wireless as opposed to a wired weather station.