Now that we moved from Enschede to Amersfoort two weeks ago, we are starting to participate in local activities. Today I joined a workshop to build a sensor-hut for the ‘Measure your city‘ project. Initiated by amongst others ‘De War‘, also the people who started FabLab Amersfoort, it is a project to crowdsource measurements to track climate and climate changes inside the city.
The national metereological institute does not measure inside cities as it does not provide data that can be compared with other measurements across the country. By building a dense grid of sensors across the city it becomes possible however to track the emergence of ‘heat islands’ or see how paving over gardens or making them greener influences the city’s microclimates.
The sensor-hub I built this afternoon is based on Arduino, and uses LoRaWan, by means of the The Things Network, to communicate. It currently holds sensors for temperature and humidity, but is prepared to also measure sunlight exposure, rain fall and soil humidity / aridity. It also has a GPS antenna, to capture the location of the device correctly.
It had been a good while since I last handled a soldering iron, but following the ‘fit for all’ building instructions after a while I ended up with a ready device. After loading the right software, it became sensor 51 in the Measure Your City network. The second stage was building a hut for the sensor device, so it measures adequately: shielded from direct sunlight, with air allowed to float around it. This so it matches up with the standards that normal metereological measurements adhere to. After a few hours me and half a dozen or so others had their own sensor-hut to install at home.
the finished device
the hut for the sensors
I haven’t properly installed the device yet: the hut still needs a white coat of paint to reflect sunlight, before mounting it in our garden at about 2 meters height. It is already taking measurements however, and it can be followed through the online database of the network’s measurements. If you look at the current data for my sensor 51, you see it also hasn’t measured its location yet. If that persists as I properly mount it outside, there might be something wrong with the GPS antenna. The temp readings are still in-house readings, and do not reflect outside temperatures.
hello world: first data log entries
I will be running a The Things Network gateway in the near future (when the Kickstarter project delivers) as well, and helped initiate a LoRaWan/The Things Network group in my previous home city Enschede. Building this sensor-hut is the first foray into exploring how I will use that cheap IoT infrastructure currently emerging in the Netherlands. I am looking to add other sensors, along the lines of what e.g. FabLab Barcelona and Waag Society have created with the smart citizen kit, or this project from Freiburg measuring particulate matter in the air.
UPDATE: GPS is working now that the sensor is placed outside. Still need to paint it white though.
Sensor hut in its intended spot in the garden