The UP wristband doesn't have a display. To get a look at all that precious fitness data, you'll need to connect the UP to an iPhone, iPad or iPod touch -- as of this writing, an Android app is in development. Plugging the TRS plug into your device's headphone jack does the trick. But how can a headphone plug transmit data?
One of the most common uses of the 3.5-millimeter jack is for headphones. But that's not the only type of data that can travel through a TRS plug. The TRS plug is made up of three conductors called the tip, ring and sleeve. When plugged into an appropriate jack, these three conductors make contact with three contact points. This allows for the transfer of data in the form of analog signals.
Data can travel in either direction along a TRS plug. When you plug in your headphones, data from your device travels through the plug up the wire to the speakers in your headphones. The speakers convert the data from electricity into sound. With the Jawbone UP, data travels from the sensor to the TRS plug into your device. The app accepts the data and translates it into a form that's easy to understand such as how many steps you've taken or calories you've burned.
The app also lets you pair your device's abilities with the UP. For example, the iPhone has a GPS receiver inside it. When going for a jog outside, you can set your app to use the iPhone's GPS receiver to track your position during an activity. When finished, you can pair your UP with the iPhone and the app combines data gathered by the motion sensor in the UP and the GPS receiver in the iPhone.
Through the app, you can elect to share your progress with others via the Jawbone UP site, or keep it all to yourself. The app can also set challenges for you to conquer throughout the day. The vibrating motor in the UP lets you set an alert -- sit still too long and the UP will begin to vibrate, signaling that it's time to get a move on.
In sleep mode, the UP registers more subtle movements. In essence, it acts like an actimetry sensor. These sensors register a person's movements as they rest and sleep. The UP system analyzes the data by processing it through proprietary algorithms. The result is a record of whether you slept like a log or tossed and turned all night long. Sleep and fitness are related -- a good night's sleep can help you reach fitness goals faster.