SensorLogger – App of the Week

Collecting data is the driving factor of the digital air we all all breathe. Taking photos, writing down your thoughts… and of course also audio recordings acquired by surveillance count to that stream of data.

But just as important as collecting data is ordering data, distilling information out of them by displaying data in a way where humans can make sense out of it. Unfortunately, there are not many civil applications for this, so normal people can‘t yet use digitalization easily to make sense out of the world.

It is the task of nerds to change this, to give this ability to the public. Alexander Stocker is one of those, working for easier methods of aggregating data. He wrote the SensorLogger app on the ownCloud marketplace, which is in alpha stage at this point, but can already be used for some cases: for example, he made a guide about how to collect climate data with his app and a Raspberry Pi. We asked him, how to write such an app, and how to contribute to the quest for more open data.

Hey Alex. Thanks for having us. About your SensorLogger app, what kind of data are your own sensors logging?

Well, I was looking for an easy solution to log climate data, in my particular case temperature and humidity, to which I should have remote access but without the need of a 3rd party hosting solution. I ended up with the conclusion that there isn’t any self-hosted solution available. That’s the reason and my motivation to start this project.

At this stage I knew ownCloud and had done some setups for private and professional use already. So, obvious to choose ownCloud to get started.

How much effort was it to come to alpha stage, and what needs to be done next?

As the ownCloud environment and the development tutorial makes it quite easy to build a skeleton app which shows basics well, it does not take long to get an application up and running. I hardly can remember how many hours it took to get alpha ready, but I guess less than a week.

Deploying an alpha release is one thing, building a full featured application is another. One of the features I would like to get finished as soon as possible is to “Share Devices”. Which means that others can have access to the logged data from a specific device. But features like delete and update “Device Groups”,”Data Types” and “Device Types” should be done some day too. So many things to do, and so little time!

What kind of sensors would you recommend if others want to use your app, too?

In general it is not a matter of which sensor to use. It’s more about how to get data sent to SensorLogger.

For instance: If one wants to log environmental data like humidity and temperature a DHT22/AM2302 or DHT11 sensor and a raspberry is a good choice. If one wants to log at which speed a cpu fan is running or the core temperature of a cpu or hard disk a simple php, python or what ever script will do the job.

I can offer my own code as an example of how to do it:

– Python: https://github.com/alexstocker/sensordata/blob/master/sensordata.py

– PHP: https://github.com/alexstocker/sensorlogger/tree/master/tests/curl

– C++ (Arduino): https://github.com/alexstocker/sensordata/blob/master/sensordata.ino

Did you learn something from the data which caused you to change parts of your life?

I would not say that collecting temperature and humidity data changed parts of my life. But if you would ask me if collected, aggregated, linked and visualized data in general could change parts of my life I would agree.

And to be honest, aggregated and linked data is changing all our lives already.

Needless to mention what Facebook, Google and intelligence services are doing.

Do you think measuring everything in our environment is empowering humans or reducing them to a factor in a calculation?

That’s a good, because philosophical question. Of my point of view, there is no simple answer. Lots of people of different disciplines and professions worry about consequences and opportunities of logging and aggregating data.

The future will tell if collecting data will empower mankind. Either we learn to use data responsively or we all will go down the history of evolution as an epic fail, as almost any civilization prior us.

Thank you Alex for your time answering our questions! I‘m looking forward to coming features of SensorLogger.

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