Position sensors

The angle of each joint in the finger is measured by a Hall effect sensor moving through the magnetic field of either a diametrically polarised ring magnet, or an axially polarised button magnet. An ADC in the proximal phalange samples the two sensors for joints 1, 2 and 3, while an ADC in the palm samples the sensor for joint 4.

The angle of each joint in the thumb is measured by a Hall effect sensor moving through the magnetic field of either a diametrically polarised ring magnet, or an axially polarised button magnet. An ADC in the middle phalange samples the distal two sensors, while an ADC in the palm samples the rest.

A pair of Hall effect sensors are used to measure Joint 5. They are placed 90º apart, and the sampled values from each sensor are added together at the host to improve the signal to noise ratio.

J0 sensors

The distal and middle joints in the fingers (J1 and J2) are internally summed and the result transmitted as J0. This is because the coupling of the joints means that they should be measured and controlled as a single joint.