How much time do you spend outside, as opposed to inside?
Whether it's because you're working, studying or just have a bunch of errands to run, it may seem like the majority of your day is spent indoors.
The device, which you can wear on your belt throughout the day, logs data which will then provide a thorough report showing the location history of the users entire day, along with with how much of that time was spent indoors and outdoors.
The device uses an accelerometer, which checks constantly for any user motion. If the user is at rest, the device's GPS and thermometer/barometer take a reading every 15 minutes. If the user is in motion, the GPS unit is automatically turned on, which will then take samples after two minutes. If the device continually detects motion it will continue taking samples every 2 minutes until the user is at rest again (to conserve energy).
All the GPS and temperature information is stored on a SD card, which can then be uploaded to a computer for further analysis. An algorithm (which the user created) will take all of the pertinent data and use it to configure the locations as indoor or outdoor and show exactly how long the user spends outdoors/indoors.
This project can be useful for people that aren't exactly sure about how much time they spend indoors. With work and school, time can become warped and by the time you realize you've been indoors all day, it's already dark outside. Check out how long you spend indoors and figure out when you can fit in a walk/run outside during your hectic day. It won't kill you to try.
What might kill you is staying indoors all damn day.