The trackpoint type sensor has 4 resistive pieces embedded. They change their resistance insignificantly upon physical force applied to the stick. There are 4 resistors in total, 2 per axis.
The resistance of every segment is approx. 3.2k. It changes +/- 10ohm upon finger-pressure. On the positive part of every axis, the pressure increases the resistance when directed to the right or up.
- temperature drift:
- "Due to the significant temperature sensitivity of the force sensors, it is necessary to recalibrate the zero force origin of each axis on a periodic basis."
- making it talk USB-HID to be compatible with any OS