Archive for the ‘Weather Station’ category

THGR810 Wireless Remote Sensor Review

October 1, 2011

One of the selling points of the Oregon Scientific series of ‘professional’ weather stations (their designation, not mine) is how easy it is to extend their capabilities by adding additional sensors. I put this to the test recently by by purchasing and installing an additional temperature and humidity sensor for my existing WMR88 weather station.

I intend upgrading to the more advanced WMR200 weather station so wanted a sensor that would be guaranteed to work on it and my WMR88. After consulting some compatibility charts provided on the Oregon Scientific web site I settled on the THGR810 which is compatible with both weather station models. Unlike the sensor that comes bundled with the WMR88 (the THGN800), the THGR810 has an LCD screen that displays the current readings. This can be handy as you can consult it directly rather than having to go to the base station. In fact it makes a good sensor even if you don’t have a base station. In addition it can operate over any one of ten channels. While my WMR88 only receives on three channels, an upgrade to the WMR200 would be able to exploit the extra channels. While I am unlikely to require more than three temperature sensors I think that it is better to have the flexibility than not. Besides the THGR810 costs £10 less than its three channel LCD screen equivalent, the THGR800.

I ordered the sensor from UK-based Weather Shop who were offering it for £30 with free delivery. The sensor arrived promptly within a few days and was well packaged. Unboxing provided me with a Sensor, Wall mount, table stand, 2 AAA batteries and instructions:

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Setting up the sensor is easy. Simply open the back compartment, insert the batteries, flip a toggle switch to choose between centigrade or fahrenheit display and finally select the broadcast channel. To save on  switches the THGR810 provides four small switches for the channel selection with different combinations of switch settings corresponding to different channels. The various settings are detailed in the manual which I will be holding onto for reference should I ever need to alter the channel.

On inserting its batteries the sensor immediately began to report temperature and humidity readings on its LCD display. Handily it also displays the current channel. It also translates the current readings into a ‘Comfort Level’ which can be one of ‘Wet’, ‘Comfortable’ and ‘Dry’. This strikes me as being a bit pointless as, if I am in the same space as the sensor to read the display, then I already know if I am comfortable or not.

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The final step was to get the sensor talking to the base station. Provided the sensor’s broadcast channel is setup correctly this is a simple matter of pressing the ‘Search’ button on the back of the base station and waiting until the sensor next sends a signal.

Once the sensor and base station were ‘paired’ I moved the sensor to its current location in the garage. Despite this being further away than the existing sensors and through several walls I have had none of the intermittent signal problems I have had with them. The difference seems to be that the signal does not have to travel through an exterior wall to get from the garage to the base station.

Installing extra sensors for the WMR88 could hardly be easier and is an inexpensive exercise in terms of time and money. My intention is to use my THGR810 as a mobile sensor which can be placed wherever I need it. The supplied table stand, as opposed to the wall mount, is perfect for this purpose as it can moved swiftly. For now it will stay in my garage in preparation for what may be a very cold winter to come.

My New Weather Station – Part Three

September 11, 2011

In my last post I detailed the process that I went through to set up my Oregon Scientific WMR88 weather station. The weather station has been up and running for two weeks now and the base station’s live reports on the weather are a nice addition to the desk of my home office.

The WMR88’s base station is quite basic compare to more expensive models. It reports live readings from each of the sensors and remembers highs and lows for elements including temperature and wind speed. What it doesn’t do is act as a data logger, i.e. it does not keep an internal record of all sensor readings it receives. Now that I have been running the weather station for a while I want to see more than simple highs and lows. I would instead like to see all historical data, preferably in graph form.  In addition publishing live sensor data to the Internet is also of interest to me. Fortunately all of this can be accomplished with the addition of a PC and the appropriate software.

The WMR88 comes supplied with a USB cable and Oregon Scientific’s Weather OS software is a free download. My advice is to ignore Weather OS entirely. It is very buggy and doesn’t provide data logging capabilities.

Happily the WMR88 is well served by alternatives. One such alternative is the Weather Station Data Logger (WSDL). WSDL is an open source Windows-based application that interfaces with a range of Oregon Scientific weather stations including the WMR88. There are many other options including the popular, multi-platform Weather Display which, although not free, is cheap to purchase and looks to be very capable, especially when combined with Weather Display Live (one weather station local to me uses Weather Display Live – its a very impressive setup including a fancy Flash display of live weather). If I get serious about data logging and internet publishing of weather data I will probably give Weather Display a closer look. However, for now I’m just tinkering so will stick with WSDL.

Setting up WSDL with the WMR88 is ridiculously easy.  Simply download and run the installer, connect the WMR88 by USB, start WSDL and select Kick Start from the File menu. As each sensor reports data to the base station it is simultaneously reported to WSDL. WSDL logs all data to a CSV and begins drawing graphs. Here is a screenshot of my temperature/humidity readings in WSDL:

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WSDL is simple to configure too. It provides a plethora of options to configure elements such as units of measurement, sensor names, graph colours and what data elements to plot.

WSDL also provides the capability to periodically upload weather information to various Internet weather websites including CWOP, Weather Underground and PWS Weather. For my setup I chose Weather Underground (Wunderground for short) simply because I have seen it mentioned in so many weather related forums.

Signing up for a Wunderground account and registering your own weather station is a straight-forward process simplfied greatly by clever use of Google Maps (to enter your elevation, latitude and longitude simply pinpoint your location on the supplied map). Armed with an assigned Wunderground Station ID and account password WSDL will upload its data to the service at defined intervals. Within minutes I could see my weather station’s data on the Wunderground website:

The sight of data from my own personal weather station on the web is just too cool.

In summary WSDL is simple to use, very configurable and feature-rich. The way software should be. The Wunderground service is no slouch either providing a means of viewing live and historical data via an intuitive interface.

I should be really happy with my new set up. I have data logging without an expensive weather station and I can, over the web, check my very-local weather (and see all historical data) from anywhere.  Unfortunately there are two issues with my set up as it stands.

The first issue is with the WMR88 itself, specifically with the wireless transmission of sensor readings. My base station is scant metres away from all of the sensors. However, it is separated from them by the outside wall of my house. This seems to be causing an issue as the base station does not pick up all sensor transmissions. I have noticed that, on occasion, either the outside temperature/humidity readings or the wind readings on the base station will go blank for a short period of time.

This is not an issue in itself. I accepted when I went for a wireless solution that it would not be 100% reliable. Convenience has its price and losing the odd reading is a fair price to pay if it avoids the need for lots of cabling. However, the amount of lost communication increases when the base station is connected to a PC by its USB cable. In this case an external sensor can disappear for minutes at a time. With some research I discovered that this is a common problem for Oregon Scientific wireless weather stations.

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.

The second issue is that I do not own a desktop PC, only a laptop. This means that I have no machine available to run weather software on a continuous basis. So far I have been experimenting with WSDL and Wunderground on my boot camped Macbook Air, a machine that travels with me frequently. To make my data logging and internet data publishing arrangement permanent I will need to purchase a desktop or media PC (I can see a Mac Mini in my future, perhaps linked to the TV and a WMR200). All in I will be looking at a serious amount of money to make this work.

(Note: I have now purchased a WMR200. You can read my thoughts on it here).

All of that is in the future, probably early next year. I have had a glimpse of what is possible but, for now, will happily make do with my relatively simple set up.

My New Weather Station – Part Two

September 4, 2011

In my last post I described the first steps in setting up my new Oregon Scientific WMR88 weather station: installing the base station to get indoor temperature, humidity readings and atmospheric pressure readings. In this post I will go into the process I undertook to install the outdoor sensors.

The WMR88 comes with three outdoor sensors:

  • Temperature & Humidity
  • Wind Sensor  (Anemometer & Wind Vane)
  • Rain Gauge

(Some special offers from Oregon Scientific also supply a UV sensor with the WMR88. Not mine however, but as I live in Scotland I don’t think that I need fear over-exposure to UV. The base station also supports up to three Temperature & Humidity sensors. I am currently considering purchasing another such sensor which I can move around my house).

I describe the installation process for each sensor below. Even with the supplied fit kits each required a little DIY on my part. DIY is something I enjoy but not something I am very good at. I therefore limit myself to small jobs where I cannot do too much damage and hire professionals for the big jobs. Fortunately the sensor installs were all relatively simple.

Temperature & Humidity Sensor Install

The Temperature & Humidity sensor is a very small unit which comes supplied with a plastic wall bracket with two fixing points. It doesn’t come supplied with fitting screws like the other sensors so I raided my loose screws box for those. The sensor needs to be placed around 1.5m from the ground and be shielded from direct sunlight and rain. More expensive weather stations come with a shielding box for this type of sensor. I would have to improvise.

I picked a spot on my fence that doesn’t get much sunlight and is partially shielded from rain by a fence beam. Fitting the sensor in place was simple enough using the wall bracket but the sensor was still a little too exposed to the elements for my liking. Fortunately I had some planks of wood-effect plastic left over from a recent door and window fitting I had at my home. I cut several pieces to size with a saw and fashioned a small shelter to shield the sensor from rain from above and sunlight from the front. This arrangement protects the sensor but leaves it well ventilated.

Here the finished product viewed from above:

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The only calibration required is to switch the sensor to channel one via a small switch inside the battery compartment. Channel one is reserved by the base station for external temperature and humidity readings.

Wind Sensor Install

Next was the wind sensor. Ideally this should have been placed high up above the roof of my house. I don’t like heights much and wanted the sensor to be accessible – after all it is battery powered and the thought of hiking up a ladder to replace batteries frequently fills me with dread. I was prepared to sacrifice the quality of readings for convenience by placing the sensor lower down. Where I live the prevailing wind direction is from the west. Happily there is a good spot near one of the side gates to take advantage of this. This happens to be right beside the Temperature & Humidity sensor.

Again, more expensive kits will come with a mounting pole, but not the WMR88. I got my pole from an old broom, painted it the same colour as the gate and drilled five fixing points through it and into the gate post. Attaching the pole to gate post with screws gave me a sensor height of eight feet. The supplied connector and U-bolt can be attached to any reasonably thick pole and the wind sensor slots easily into the connector.

The only tricky part was ensuring that the wind sensor was pointing North. With a round pole and the U-bolt it is easy to adjust the wind sensors facing before a final tightening to keep it in place. I used my iPhone’s built in compass to ensure I had the sensor facing North.

Here is the finished installation:

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Rain Gauge Install

The rain gauge was the most difficult sensor to install. It has to be in an open area and must be completely level. The former ensures that the funnel captures the required amount of rainfall for an accurate reading while the latter helps captured rainfall to drain away easily. My shed (only a few meters from the other sensors) is a good spot for capturing rainfall but has no flat surface. To get around this I built a small shelf onto the side of the shed just under the roof line using a couple of steel brackets and some spare wood. The wood was not completely flat but the fit kit comes with a number of washers that solved this issue. Using a spirit measure and the supplied washers I was able to secure the rain gauge to its shelf by each of its four screw-mounted feet such that it was completely level.

The finished product:

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With all three sensors in place and the supplied batteries inserted into each I retired inside to check that I was receiving data on the base station. It was soon raining and the wind was increasing nicely (did I mention I live in Scotland?). This was fortunate as I could confirm readings from all of the sensors and see them alter in response to the changing conditions.

At the time of writing I have had my weather station operational for a week. It is quite interesting to compare what the weather station tells me as compared to what I can see out of the window. I have noticed that previously I had a tendency to over-estimate what I was seeing outside. For example, when I think it must be very windy the weather station actually tells me that the conditions I am seeing are only the result of a  20 mph moderate breeze as opposed to the strong wind I presumed was present.  The same goes for rainfall – while a sudden downpour may look to me like it is dumping an inch of water the rain gauge reports a more reasonable couple of millimetres.

In my next post I will conclude this series by investigating using a PC to extend my weather station for data logging and publishing weather data to the web.

My New Weather Station – Part One

August 28, 2011

Since I completed the ‘Understanding the Weather’ Open University Short Science Course late last year I’ve been bitten by the weather bug. I keep a close eye on weather forecasts on both the UK MET Office web site and on the television and examine the sky to try and forecast short term (4-6 hour) changes in the weather. Given my new-found interest in meteorology the logical next step would be to setup my own home weather station and that is exactly what I have done this weekend.

A home weather station will typically comprise of a range of sensor to measure temperature, humidity, atmospheric pressure, wind speed, wind direction and rainfall. In addition, it will include a base station to collate the readings from the various sensors and present them via a screen. The sensors communicate with their base station wirelessly. Optionally data can be collected from the base station for use with a PC. Really fancy weather stations will go one better and automatically record all readings to a data logger and report it live to a web site.

When purchasing a home weather station it is possible to spend a relatively little (< £100) or a lot (> £1,000). As this is my first weather station I did not want to be too extravagant but, at the same time, didn’t want to buy cheap kit which was not fit for purpose. After some research I settled on an Oregon Scientific WMR88 which retails at £150. This package includes three separate outdoor sensors for temperature/humidity, wind speed/wind direction and rainfall. Having separate sensors was crucial for me as an all-in-one sensor solution would not work well on my property as each sensor has different criteria for optimal placement. Where I live there is no single place that would satisfy this criteria for all sensor types. In addition to the outdoor sensors the base station also measures indoor temperature/humidity and atmospheric pressure. The WMR88 allows a PC to be hooked up to the base station via USB for weather data to be extracted in realtime. While looking at live and summarised weather data on the base station’s screen is cool actually having the data to play with is even better.

As luck would have it Amazon were offering a discount on this model. In fact the discount was so hefty it struck me as being a mistake on their part – £75 was all they were asking. This was so cheap that it would cost less than lesser Oregon Scientific weather stations they were also selling. I ordered my bargain immediately and noted that scant hours later the price had risen to £130. To their credit Amazon have billed me £75 despite this being an obvious listing error.

My weather station arrived four days later in a large but well packaged and well presented box:

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I immediately unpackaged the contents and compared them with the manifest in the instructions:

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Top-left: Rain Gauge, Fixing Set of 4 screws and 6 washers, 2AA batteries

Top-Right: Wind Sensor (Anemometer & Wind Vane), Connector, U-bolt, 4 screws, 2 AA batteries

Bottom-left: Temperature & Humidity Sensor, Wall mount, table stand, 2 AAA batteries

Bottom-middle: Quick Start Guide and Manual

Bottom-right: Base station, USB cable, Power Adapter, 4 AA batteries

The kit contains everything needed to get up and running for an ideal install. That is, where you happen to have perfect install locations for the sensors on your property. I didn’t have ideal locations which is where most of the fun of the install came from and which I will describe in part 2 of this post.

The PC software was not included but is a free download. This makes a lot of sense as software CDs tend to be a waste for non-networking kit as they typically hold out-of-date versions of software.

Everything was present but not everything was correct. All sensors and the base station are battery powered. However, there is the option of powering the base station with the supplied power adapter. Unfortunately the adapter I had been supplied with was the EU model not the UK one. A quick call to Amazon resolved the issue to my satisfaction (to be fair they called me immediately after I completed an online form with my telephone number – this is great customer service). I was offered a replacement or a £10 discount. I gratefully accepted the latter as I knew I could source an EU to UK adapter for only a couple of pounds and did not want to wait for a replacement. In the meantime the base station could operate off batteries. My weather station was now even more of a bargain at less that half price.

The first step was to get the base station up and running. This is a simple matter of powering it via batteries or the power adapter. It will immediately begin displaying indoor temperature and humidity data as well as atmospheric pressure. The only calibration required is to set your altitude as atmospheric pressure readings must be adjusted for higher altitudes. Finding the altitude at your location is made easy by various online services. Used this one daftlogic.com. Entering the value into the base station is simple enough and accepts values in the tens of metres (more than accurate enough for the pressure adjustment the base station will carry out).

The base station also records the current data and time. This is useful when looking at min and max records as these timestamped and for the built in moon phase display. You can set the date and time manually but its easier to let it set itself using clock synchronisation. This nifty feature has the base station listen out for time synchronisation signals from Anthorn in NW England where several atomic clocks are located and set its date and time automatically.

The base station displays a wealth of information including the latest sensor readings in various units of measurement, 24-hour highs and lows with timestamps, derived measurements such as wind chill and dew point, a local forecast based on sensor readings and the moon phase. Here it is with the timed back-light on and all sensors hooked up:

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I only have two minor issues with the base station. First of all some of the smaller items on the display can be difficult to read. Fortunately the small text is confined to a minority of labels rather than actual readings and the inclusion of a strong back-light helps. The second issue has no work-around and is that the base station emits a loud beep whenever a button a navigation button is pressed. This is irritating and I cannot find a way to switch it off. However, these are niggling flaws and otherwise the base station is a nice bit of kit which looks good in the living room and presents its information intuitively.

In follow-up posts I will describe the process of fitting the outdoor sensors and collecting data from the base station to PC. This is where the real fun is to be had.