Measuring joint angles
A new joint has been designed to fit surface mount potentiometers as mentioned in the sensor blog post. The potentiometer is in line with the hinge to measure the angle of the part.
The potentiometer is mounted on the side of each finger, and thanks to the thin design, does not add much the the thickness of the current finger design.
The potentiometer is connected to 3.3v and GND, with the wiper going to an analog pin of the Teensey 3.2. Using a simple analog read script the value of the potentiometers on each joint are measured and printed to the serial terminal at intervals of 25ms.
As can be seen by the results below, there is some clear noise on the signal, however this is very small comparted to the full sweep of the sensor. The gragh below shows both joints bending through the full 90 degree arc several times.
When the feedback in implemented, a zero-order hold, or filtering may be needed such as a low pass filter.