Resonance is a simple analog circuit simulator app for Processing. The schematic shown is a simple RC low-pass filter. As the frequency increases or as the capacitance increases or as the resistance decreases, the OUT1 voltage increases. I have programmed a graphing utility and a vector diagram but in this upload only the vector diagram is visible. The vector displays the circuit's total impedance (diagonal) as the result of the capacitance (vertical) and the resistance (horizontal). With the default component values, the vector will appear only as a black dot on the right side of the window. To make the vector more visible, lower the capacitance value of the capacitor and increase the resistance value of the resistor (instructions for modifying component values described below). I plan to add more schematics but for now the RC low-pass filter is the only one I have programmed (I will also enable the ability to switch between viewing the graph and the vector diagram). I plan to give the app Arduino interface functionality via serial communication(haven't coded that yet either :P). The Arduino will be programmed to test for the value of a capacitor, resistor, inductor, or ac source (this will be done using external circuitry) and create a new capacitor, resistor, inductor, or ac source object with the test value. You could effectively import an entire circuit into the processing and simulate the circuit's output.
Use SPACE to select a component when the mouse is over. This will change the outline to a green-blue. To deselect, press SPACE when the mouse is not over the component. While selected, a component's value can be changed by using W, A, S, D. W - increases the increment value (10) S - decreases the increment value (.1) A - decrease the component's value by the increment D - increase the component's value by the increment
Comment if you have any questions.