The keyboard-application was the most intricate in the development of Senseboard. That drove most of the sensor development. It started with the simple pressure switch, and was followed by a limited IMU and at the end it had a five degree IMU.
The fingers position were measured by Electric Field Sensing (see more at sensor) and the combination with IMU a learning system (based on ANN – Artificial Neural Networks) could learn your way of typing a text. After typing one page the system could read the typing. The accuracy was, however, only 90-95%.