Educational Arduino powered weather station

For an educational project at the HAS (Geo Media and Design) students, I’m working on a digital weather station, built around the Arduino prototyping system.

The RHT03 sensor for temperature and humidity was up and running in minutes, which I did months ago already. I still had to hook up the barometric sensor, and this one took some more effort to get playing. Switching myself into ‘sustained programming mode’ yesterday evening, for a couple of hours until 1:15 AM, did help, as did a lot of Googling. The problem was that the tutorials and the available libraries for the sensor (BMP085) did not exactly match, the Arduino ‘Leonardo’ pin layout is slightly different from the other Arduino’s, and as a bonus there are multiple versions of the BMP085 breakout board.

I figured out how to get everything up-and-running. After messing around with different libraries, some not properly installed, others not compatible, the final trick appeared to be using a 5V power supply instead of 3.3V. The power voltage depends on the version of the breakout board, but the sensor itselfs can only handle 3.6V, so I was a bit afraid of putting 5V on the line, until I was sure that this version of the breakout board included a voltage regulator. Not all breakout boards do…

After a full night of measuring while I had a good rest, all the data was nicely recorded in my database. Comparing my results with the semi professional weather station in the near vicinity shows totally acceptable results:

  • +1 degree C
  • -5% RH
  • -1 hPa (millibar)

This can all be explained by the simple fact that the sensor was just outside the window on the third floor.

I will post the technical details (used libraries, code, wiring) on my wiki sooner or later, I’ll add the link by then. The next step will be a simple web-viewer on the database, where I’ll be working on now.

Soldering the pins to the breakout board for the barometric pressure sensor (BMP085).


The full set up: Arduino + breadboard with barometric pressure sensor, the big light-grey cable connects to the temperature and relative humidity sensor (RHT03).


Live, streaming measurement data in my ‘Python weather station manager’.


The Netherlands at night as seen from ISS

A few months ago I had the honor to prepare images of The Netherlands at night, taken from the ISS by Andre Kuipers (and others). The images had to be published as a WMS webservice, so they could be embedded in the ‘Atlas Leefomgeving‘. The imagery itself is located under: ‘Licht’, ‘ISS Foto NL’.

From a technical point of view, I described in my wiki how to achieve this:
WMS, Mosaicking large images. Attempts by others to assemble the multiple large images using $$$$$ GIS software failed, so this is also a nice showcase for the power of open source GIS software!
To my regret, the display of the imagery is incredibly slow in the Atlas, compared to the super high-speed WMS service itself ( < 1 second at any scale: untiled and not cached!). Screen Shot 2013-11-17 at 14.04.22Atlas Leefomgeving, NL at night from ISS

Archaeology is married with technology

I’m absolutely convinced that archaeology goes hand in hand with technology, especially in dealing with spatial data, as was confirmed once again at the chnt 2013 () and maybe even more than ever.
The level of the lectures was high, I really enjoyed many of them.
Yesterday I had the honor to chair a discussion which developed in a very nice way, despite the time of the day!
A rewarding trip, and at the end I enjoyed a bit of Vienna, while rushing to the airport!

Who doesn’t like mini helicopters with laser scanners?

Always fun here, at the Cultural Heritage and New Technologies conference in Vienna.
Lots of stuff on developments in data exchange, authenticity, storage, VR, 3/4D, all related to archaeology.
Interestingly, archaeologists tend to be very advanced, and making progress at an incredible rate, progress speed seems to have even increased in the past 2 years (I’m visiting the conference since 2005) although they’re still digging in the past!
Basically the concepts also apply to landscape designers and geographers, so developments in this area could  even be interesting for Geo Media & Design @ HAS!

Lecturer at the HAS: a new challenge

This week I started at the HAS University of Applied Sciences, where I’ll be teaching geo-related subjects, primarily but not limited to GIS in the broadest sense, and spatial databases. A bit of¬†research is also in the mix, and unbelievable, even audio editing!

The HAS is a vibrant school, with lots of room for development, which looks very attractive to me.¬†Transfering knowledge is challenging, but very rewarding, I’m dedicated to making the course a succes, and hopefully enjoy it!

The first week was promising!

XWiki upgrade

Wikis are great for sharing information and documenting, and the XWiki wiki is one of the best I think. Only the upgrade process can be a bit cumbersome, especially on very large databases. Also, when you’re using PostgreSQL, (you should, it is way more advanced than the most well known open source database), you could run into trouble during a database schema upgrade.

How to act, for a smooth upgrade (I just upgraded from XWiki version 2.6 to 5.1).

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