/*
Matrix: Kapton + Copper
A simple pressure sensor matrix made from two Kapton film sheets with
7×7 copper tape traces and a piece of Velostat or Eeonyx piezoresistive
material in between.
parsing through this grid by switching individual rows/columns to be
HIGH, LOW or INPUT (high impedance) to detect location and pressure.
>> http://howtogetwhatyouwant.at/
*/

#define numRows 7
#define numCols 7
#define sensorPoints numRows*numCols

int rows[] = {A0, A1, A2, A3, A4, A5, A6};
int cols[] = {11,10,9,8,7,6,5};
int incomingValues[sensorPoints] = {};

void setup() {
// set all rows and columns to INPUT (high impedance):
for (int i = 0; i < numRows; i++) { pinMode(rows[i], INPUT_PULLUP); } for (int i = 0; i < numCols; i++) { pinMode(cols[i], INPUT); } Serial.begin(9600); } void loop() { for (int colCount = 0; colCount < numCols; colCount++) { pinMode(cols[colCount], OUTPUT); // set as OUTPUT digitalWrite(cols[colCount], LOW); // set LOW for (int rowCount = 0; rowCount < numRows; rowCount++) { incomingValues[colCount * numRows + rowCount] = analogRead(rows[rowCount]); // read INPUT }// end rowCount pinMode(cols[colCount], INPUT); // set back to INPUT! }// end colCount // Print the incoming values of the grid: for (int i = 0; i < sensorPoints; i++) { Serial.print(incomingValues[i]); if (i < sensorPoints - 1) Serial.print("\t"); } Serial.println(); delay(10); }

/*
Code based on Tom Igoe’s Serial Graphing Sketch
>> http://wiki.processing.org/w/Tom_Igoe_Interview

Reads X analog inputs and visualizes them by drawing a grid
using grayscale shading of each square to represent sensor value.
>>
*/

import processing.serial.*;

Serial myPort; // The serial port
int maxNumberOfSensors = 49;
float[] sensorValue = new float[maxNumberOfSensors]; // global variable for storing mapped sensor values
float[] previousValue = new float[maxNumberOfSensors]; // array of previous values
int rectSize = 0;
int rectY;
void setup () {
size(600, 600); // set up the window to whatever size you want
rectSize = width/7;

println(Serial.list()); // List all the available serial ports
String portName = Serial.list()[2];
myPort = new Serial(this, portName, 9600);
myPort.clear();
myPort.bufferUntil(‘\n’); // don’t generate a serialEvent() until you get a newline (\n) byte
background(255); // set inital background
smooth(); // turn on antialiasing
rectMode(CORNER);
}

void draw () {
for (int i = 0; i < maxNumberOfSensors; i++) { fill(sensorValue[i]); rect(rectSize * (i%7), rectY, rectSize, rectSize); //top left if((i+1) % 7 == 0) rectY += rectSize; println(rectY); } rectY=0; } void serialEvent (Serial myPort) { String inString = myPort.readStringUntil('\n'); // get the ASCII string if (inString != null) { // if it's not empty inString = trim(inString); // trim off any whitespace int incomingValues[] = int(split(inString, "\t")); // convert to an array of ints if (incomingValues.length <= maxNumberOfSensors && incomingValues.length > 0) {
for (int i = 0; i < incomingValues.length; i++) { // map the incoming values (0 to 1023) to an appropriate gray-scale range (0-255): sensorValue[i] = map(incomingValues[i], 0, 1023, 0, 255); //println(sensorValue[i]); } } } }