An open assignment for an interesting course I followed had the goal of creating a new novel design tool with audio feedback.
For this I created a capacitive sensor. This sensor consists of a wire sticking straight up. The principle of a capacitive sensor works by being one half of a capacitor. Your hand or anything else that can store capacitance is the other half of the capacitor.
The capacitiveSensor method toggles a microcontroller send pin to a new state and then waits for the receive pin to change to the same state as the send pin. A variable is incremented inside a while loop to time the receive pin’s state change. The method then reports the variable’s value, which is in arbitrary units.
This measured value is sent to the computer where software written in processing uses this value for display purposes. As a visualization a constantly updating stack of circles is used. This gives the impression of a tube. A new circle is drawn with the measured value of the sensor. Also an tone is played based on this value. This makes it a rudimentary theremin. The audio feedback gives extra depth to moving your hand around the sensor and gives the user directly a better understanding of how his actions change the visualization.