The first thing I want to find out: How are the swinging characteristics of trees? I'm mainly looking into frequency and amplitude. The goal is to use this data together with knowledge about size and weight of the tree to find out how many energy is in the swinging motion. In parallel I'm doing some research in the scientific literature, but there is no alternative to get some hard, reallife data! The first idea here was to put a logging device onto the tree which can log the acceleration and after some calculation I would have the position over time and with that the data I'm looking for.

So the question is, how to get the data the easiest way. Since I have done a lot with Arduinos, this was my first thought, so I put together a logging platform in my mind: An Arduino Uno with a SD card shield, a accelerometer, a battery  and some lines of code and, voila, the logging device is ready. But then I came to my mind, that basically the same components are inside a modern mobile phone. Luckily I had one in my "old electronics devices, which I don't use anymore, but could be come handy sometime" bin, so basically what was left to do is just downloading an app (offcourse there was an app for that!). And it is a  IP67 rated one, which means it is water proof, perfect!

Today I will put the phone on the tree and hope for a small storm coming to get some data the next days. Stay tuned for more!

PS: The phone by the way is a SPT-900 from Simvalley and runs Android 4.2. The built in accelerometer should be according to one of the apps a MMA8452Q from NXP and therefore sufficient for this purpose.