Esprit "IT for Mobility" 26900
Home
Hardware
Software
Publications
sensors
TEA-I
TEA-II
context awareness
algorithms
results & data
research papers
press articles
seminars & demos

The first TEA sensorboard

The design of the first prototype board is:

  • Generic. It is meant to be a development of a long lasting standard 
  • Flexible. The TEA sensorboard is a flexible system,  from the point of view of sensors and processing 
  • Small. A small portable system, that fulfills the need for mobility 
A small, portable hardware device called "TEA Sensor-Board" is responsible for acquiring the data that was used in the first phase of the project. It is a prototype that enables to acquire raw sensor data. The sensor board is equipped with many different low-level sensors and a chip that digitises the analog signals from the sensors at a certain rate. This frequency can be different for every sensor and depends on how quickly a value of a certain sensor can change. An acceleration sensor for instance is probed about 100 times per second, while a temperature sensor is probed only once a second. 
It can be connected to a desktop computer or a laptop with a standard serial cable and needs two 9V batteries (one for the CO sensor). TEA1 contains a PIC16C73A/B programmable microprocessor that controls the A/D converter and serial communication, and also the heating and reading of CO Timing is done by a 16MHz oscillator. The program on the PIC is a polling program that provides the host (via serial communication) with the sensordata. 
TEA1 also contains a AD7828 (an 8 bit/8 channel converter)with 3 address lines from the Pic that controls the polling. Flexibility is also gained through analog switches, which allow to add more sensors.

The basic sensors are:
  • light sensor (photodiode)
  • microphone
  • CO-sensor
  • Infrared sensor
  • accelerometer for the X axis
  • accelerometer for the Y axis
  • pressure
  • temperature
  • But we also experimented with additional bio sensors.

    last update: 27/06/2000 by Kristof Van Laerhoven the previous sites can still be found here and here