News

Another problem that was forgotten in my previous post, what that of the data collection software appearing to stall in warmer weather (above around 22 degrees).  This issue was linked to the high humidity readings being observed around the same times.  This has now been resolved by suppling supplementary power (+19V) to the equipment on the roof.  Althought this power supply is meant to be optional, something must have been creating a demand for it... higher resistance due to the heat? Maybe.

Anyway, I will continue to observe the humidity readings to make sure there's no issue with faulty sensors.

* goes off to enjoy a BBQ in the rare summer sun...

3 years down the line, and I've decided it's time to post some more news.  In that time I've started and completed my degree in Computer Science at the University of Warwick, coming out with a First Class Honours result.  Because of that I've had very little time to give the weather station the care and attention it deserves.  Regular visitors may have noticed strange things happening over the years, but things got worse in around May this year when the wind instrument had to be taken down when it suddenly stopped working.  On top of this the solar sensor had been broken for many more months - giving constant readings in the 80-100% range.

Now university is over I've spent almost a solid weekend tweaking things:

• The weather station is mounted in a slightly different location.  During the winter months the heat from the boiler was affecting the temperature reading, so it's been moved further away from the chimney to prevent this.  The wind instrument has also been mounted slightly higher in order to get better readings.
• The humidity sensor has been moved in to a new pagoda with the outdoor temperature sensor.  The new design has easier to use RJ-45 connectors so the network can be reconfigured easily, and malfunctioning sensors can be disconnected without taking down everything else.
• A new solar sensor is in place, mounted on top of the pagoda.
• New cable has been laid to all outdoor sensors, as the old stuff was getting brittle from sun exposure.
• The rain gauge has been recalibrated as readings were nearly double what they should have been.

The only outstanding issue is that of humidity readings; the values being reported seem to be higher than expected.  This will be investigated over the coming weeks.  Possible causes include lack of ventilation for the pagoda and dampness on the velcro strip that holds the sensor case in place.

Once the hardware is fully functional again, I might even start working on a new website, as this one is starting to look a little dated!  The other problem I'm having is with the sheer volume of data - there have been over 3 million readings taken over the years, so queries against this for statistical information are getting very slow and expensive.  Some sort of partitioning scheme will have to be worked out for this.

I hope these improvements will keep the weather station active for many years to come.  I'll try to provide more regular updates now I have the time for it!

Fact of the day: this website receives nearly 1000 unique visitors per month! Thank you all for looking.

The humidity sensor was returned yesterday, and I've been testing it indoors since then.  The temperature reading from the board can currently be seen as 'Perspex pagoda' on the Technical Info page.

I've been experimenting with AJAX (Asynchronous JavaScript And XML) a little on the site now to improve the usability and experience of the site.  My latest addition means that weather data can now be displayed in real time without having to refresh the page.  To the left you'll notice a countdown (assuming you have javascript enabled).  When it reaches zero the data in the left menu column is refreshed automatically, and this continues to happen every minute you leave the page open for.  Additionally you can leave the main page of the site up and the current weather data and images on that page will automatically refresh every minute too.  To refresh the data manually, but without reloading the entire page you can use the Force Update link to the left.