I decided to use the capacitors as a creator of random noise. The project outcome was very entertaining and I was able to study the distances that created different noises. There is a switch to allow it to be turned on and off.

You will need:











- a tone generator. Here I use the vertical strips of the breadboard since it is easier to plug in the tone and make sure the pins are not on the same strip.











- two copper sheets on paper attached to respectice wire.

- and a switch.

I am using Rob's microcontroller. This controller worked better than the Adafruit one, and did not require me to download the driver for Metro (which I was having difficulty with) for capactive touch). I did have to install the MattairTech board pack for Arduino and select the Generic D11C14A board.

The code used:

            //tx_rx03  Robert Hart Mar 2019.
            //  Program to use transmit-receive across space between two conductors.
            //  One conductor attached to digital pin, another to analog pin.
            //
            //  This program has a function "tx_rx() which returns the value in a long integer.
            //
            //  Optionally, two resistors (1 MOhm or greater) can be placed between 5V and GND, with
            //  the signal connected between them so that the steady-state voltage is 2.5 Volts.
            //
            //  Signal varies with electric field coupling between conductors, and can
            //  be used to measure many things related to position, overlap, and intervening material
            //  between the two conductors.
            //


            long result;   //variable for the result of the tx_rx measurement.
            int analog_pin = 2;
            int tx_pin = 9;
            int switch_pin = 13;
            int tone_pin= 5;

            void setup() {
                pinMode(tx_pin, OUTPUT);      //Pin 4 provides the voltage step
                pinMode(switch_pin, INPUT);
                Serial.begin(9600);
            }


            long tx_rx(){         //Function to execute rx_tx algorithm and return a value
                                //that depends on coupling of two electrodes.
                                //Value returned is a long integer.
                int read_high;
                int read_low;
                int diff;
                long int sum;
                int N_samples = 200;    //Number of samples to take.  Larger number slows it down, but reduces scatter.
                int t=0; //to be used to signal off
                sum = 0;

                for (int i = 0; i < N_samples; i++){
                    digitalWrite(tx_pin,HIGH);              //Step the voltage high on conductor 1.
                    read_high = analogRead(analog_pin);        //Measure response of conductor 2.
                    delayMicroseconds(100);            //Delay to reach steady state.
                    digitalWrite(tx_pin,LOW);               //Step the voltage to zero on conductor 1.
                    read_low = analogRead(analog_pin);         //Measure response of conductor 2.
                    diff = read_high - read_low;       //desired answer is the difference between high and low.
                    sum += diff;                       //Sums up N_samples of these measurements.
                }
                return sum;
            }                         
            //End of tx_rx function.


            void loop() {

                //switch on
                if (digitalRead(switch_pin) == HIGH){
                      int pitch1 = result/800;
                      tone(tone_pin, pitch1);
                }       
                //switch off
            }