Esprit "IT for Mobility" 26900
context awareness
results & data
research papers
press articles
seminars & demos
It is Small

The second version of the TEA sensorboard has been tailored to slip into the back of an enlarged battery casing which fits into the Nokia 6110-6150 Series. The dimensions of the board are approximately 85mm x 35mm x 0.6mm.  The TEA2 board is a sensor board stuffed with 8 sensors, 3 of them doubly redundant, micro-contoller and serial communication. It has been designed with low power IC?s to receive power by a mobile phone battery outputting 3.6 volts. 
The TEA2 board has two communication slots: one standard serial RS232 port to make communication possible with a laptop or PDA and one Nokia port for communication with a Nokia 6110-6150 Mobile Phone.

It has Sensors
The sensors on the board are comprised of two photodiodes, two microphones, a dual axis accelerometer, a digital temperature sensor and a touch sensor. The microphones are miniature electrolet  capsules regularly used in mobile phone applications. The accelerometer IC is the ADXL202 from Analog Devices and the digital temperature is the Dallas Semiconductor DS1820. These signals are then fed either through direct digital inputs or analog lines into the Microchip PIC16F877 microprocessor, which runs at 20MHz. Apart from these sensors, additional slots for other sensors are available.

It is Smart

The PIC16F877 is a powerful 8-bit micro-controller with a 10-bit A/D converter and in circuit programming. The PIC does the data polling and the mathematical manipulation required for the cue extraction(= basic pre-processing of the raw sensor values). The cues are then fed either via a MAX232 chip with DB9 connector or directly to the phone for profile selection.The TEA2 board is integrated into the back of the battery casing, thus enabling it to simply slide into the phone without having to hack into the phone unit itself. This way we reach modular context awareness, where the context awareness is actually an autonomous module that can be plugged into various mobile devices.
See our TEA2 Guide for programmers for more technical data on the programming and layout of the 16F877.

The mobile phone demonstrator: The Debug Pack
This is our debug prototype, incorporating phone, battery, and TEA2 board, but with the bottom of the cover cut-off to easily reach and re-position the sensors (click the pictures to see a larger version). The connection between phone and TEA board is also external. The TEA2 board and the phone both use an ultra-thin Nokia Li-Polymer battery, which can supply enough power to run both components for at least a whole day. 
The TEA2 board is connected to the phone by its FBUS connector (in this version done by a small external cable - later versions have a connector built in the module), providing communication between the TEA device and the mobile phone.

The small microprocessor on the TEA2 board does the aquisition of the sensordata, the pre-processing of that data and the classification of it by a Self-Organizing Map (pretrained, but still slightly adaptive), as well as the communication with the phone.
The mobile phone was chosen as a case study for several reasons. First of all, Nokia is a member of the TEA consortium and has the know-how for accessing the phone's communication protocol and the battery circuit. Second, the mobile phone is a typical example of how context awareness can help improving mobile devices, since it's ringing tends not only to disturb the user, but also the people around the user. Third, mobile phones have already a profiles-menu, which can be used to define the behavior for the different contexts (profiles).
This way, the TEA2 board can distinguish various contexts related to the device itself, such as "sitting in a pocket", "lying on the desk", "in user's hand", and can ask the phone to switch to another profile. The profile has settings that relate to (and are named after) these contexts.
For instance, the TEA board will detect when the user puts his phone in his pocket, so it asks the phone to switch to the "in pocket" profile, which -among other things- sets the phones' behavior to ringing loudly. Later, the user puts the device on his desk. TEA agains notices this and makes the phone switch to the "on desk" profile, which lowers the ringing volume, since it is already very well audible.
Phone profiles are very versatile: they can not only change the volume of the ringing, but also the ringing tone, whether the phone should vibrate, etc. and this for both phone calls and messages. The user can change this behavior via the phone's menu and alter the phone's behavior for a certain profile whatever way he/she likes to.
The mobile phone demonstrator: The User-Tesing Pack, beta version

This is a first prototype (opened up) incorporating phone, battery, TEA board, and the top cover (which is actually a bit to big). Click the pictures to see a larger one. This version has all components build in (no external cables - just some sensors that are visible), and can be added or removed like a standard battery pack.

More pictures and user testing results will be added later on.
last update: 04/04/2001 by Kristof Van Laerhoven the previous sites can still be found here and here