Using this program it is possible to read a analog 6x8 matrix sensor connected to an Arduino and visualize the read out on a matrix using Processing.

Sensor is connected to Arduino so that digital pins 2 to 9 are connected to the 9 rows of the sensor, while the 6 columns are connected to Analog pins 0 to 5.

Arduino program

int Pin0 = A0;        // sensor attached to analog Pin0
int Pin1 = A1;            // sensor attached to analog Pin1
int Pin2 = A2;        // sensor attached to analog Pin2
int Pin3 = A3;        // sensor attached to analog Pin3
int Pin4 = A4;        // sensor attached to analog Pin4
int Pin5 = A5;        // sensor attached to analog Pin5

 
const int dPin2 = 2; //output attached to digital Pin 2 = sensor row 0
const int dPin3 = 3; //output attached to digital Pin 3 = sensor row 1
const int dPin4 = 4; //output attached to digital Pin 4 = sensor row 2
const int dPin5 = 5; //output attached to digital Pin 5 = sensor row 3
const int dPin6 = 6; //output attached to digital Pin 6 = sensor row 4
const int dPin7 = 7; //output attached to digital Pin 7 = sensor row 5
const int dPin8 = 8; //output attached to digital Pin 8 = sensor row 6
const int dPin9 = 9; //output attached to digital Pin 9 = sensor row 7

int sensorValue0 = 0; //value read from line 0 of the sensor
int sensorValue1 = 1; //value read from line 1 of the sensor
int sensorValue2 = 2; //value read from line 2 of the sensor
int sensorValue3 = 3; //value read from line 3 of the sensor
int sensorValue4 = 4; //value read from line 4 of the sensor
int sensorValue5 = 5; //value read from line 5 of the sensor

int msensorValue0 = 0; // mapped value read from line 0 of the sensor
int msensorValue1 = 1; // mapped value read from line 1 of the sensor
int msensorValue2 = 2; // mapped value read from line 2 of the sensor
int msensorValue3 = 3; // mapped value read from line 3 of the sensor
int msensorValue4 = 4; // mapped value read from line 4 of the sensor
int msensorValue5 = 5; // mapped value read from line 5 of the sensor

void setup() {
pinMode(dPin2, OUTPUT);  //pin2 is an OUTPUT
pinMode(dPin3, OUTPUT);  //pin3 is an OUTPUT
pinMode(dPin4, OUTPUT);  //pin4 is an OUTPUT
pinMode(dPin5, OUTPUT);  //pin5 is an OUTPUT
pinMode(dPin6, OUTPUT);  //pin6 is an OUTPUT
pinMode(dPin7, OUTPUT);  //pin7 is an OUTPUT
pinMode(dPin8, OUTPUT);  //pin8 is an OUTPUT
pinMode(dPin9, OUTPUT);  //pin9 is an OUTPUT


  Serial.begin(9600);
}

void loop()
{
  digitalWrite (dPin9, HIGH); //turn row0 on
  sensorValue0 = analogRead (Pin5); //read value column 0
  // wait 10 milliseconds before the next loop
  // for the analog-to-digital converter to settle
  // after the last reading:
  delay(10);  
  sensorValue1 = analogRead (Pin4); //read value column 1
  delay(10);
  sensorValue2 = analogRead (Pin3); //read value column 2
  delay(10);
  sensorValue3 = analogRead (Pin2); //read value column 3
  delay(10);
  sensorValue4 = analogRead (Pin1); //read value column 4
  delay(10);
  sensorValue5 = analogRead (Pin0); //read value column 5
  delay(10);
  digitalWrite (dPin9, LOW); //turn row0 off
 
  msensorValue0 = map (sensorValue0, 0, 1023, 255, 0);
  msensorValue1 = map (sensorValue1, 0, 1023, 255, 0);
  msensorValue2 = map (sensorValue2, 0, 1023, 255, 0);
  msensorValue3 = map (sensorValue3, 0, 1023, 255, 0);
  msensorValue4 = map (sensorValue4, 0, 1023, 255, 0);
  msensorValue5 = map (sensorValue5, 0, 1023, 255, 0);
 
  Serial.print(msensorValue0);
  Serial.print(',');
  Serial.print(msensorValue1);
  Serial.print(',');
  Serial.print(msensorValue2);
  Serial.print(',');
  Serial.print(msensorValue3);
  Serial.print(',');
  Serial.print(msensorValue4);
  Serial.print(',');
  Serial.print(msensorValue5);
  Serial.print(',');
  
 digitalWrite (dPin8, HIGH); //turn row0 on
  sensorValue0 = analogRead (Pin5); //read value column 0
  // wait 10 milliseconds before the next loop
  // for the analog-to-digital converter to settle
  // after the last reading:
  delay(10);  
  sensorValue1 = analogRead (Pin4); //read value column 1
  delay(10);
  sensorValue2 = analogRead (Pin3); //read value column 2
  delay(10);
  sensorValue3 = analogRead (Pin2); //read value column 3
  delay(10);
  sensorValue4 = analogRead (Pin1); //read value column 4
  delay(10);
  sensorValue5 = analogRead (Pin0); //read value column 5
  delay(10);
  digitalWrite (dPin8, LOW); //turn row0 off
 
  msensorValue0 = map (sensorValue0, 0, 1023, 255, 0);
  msensorValue1 = map (sensorValue1, 0, 1023, 255, 0);
  msensorValue2 = map (sensorValue2, 0, 1023, 255, 0);
  msensorValue3 = map (sensorValue3, 0, 1023, 255, 0);
  msensorValue4 = map (sensorValue4, 0, 1023, 255, 0);
  msensorValue5 = map (sensorValue5, 0, 1023, 255, 0);
 
 Serial.print(msensorValue0);
  Serial.print(',');
  Serial.print(msensorValue1);
  Serial.print(',');
  Serial.print(msensorValue2);
  Serial.print(',');
  Serial.print(msensorValue3);
  Serial.print(',');
  Serial.print(msensorValue4);
  Serial.print(',');
  Serial.print(msensorValue5);
  Serial.print(',');
  
digitalWrite (dPin7, HIGH); //turn row0 on
  sensorValue0 = analogRead (Pin5); //read value column 0
  // wait 10 milliseconds before the next loop
  // for the analog-to-digital converter to settle
  // after the last reading:
  delay(10);  
  sensorValue1 = analogRead (Pin4); //read value column 1
  delay(10);
  sensorValue2 = analogRead (Pin3); //read value column 2
  delay(10);
  sensorValue3 = analogRead (Pin2); //read value column 3
  delay(10);
  sensorValue4 = analogRead (Pin1); //read value column 4
  delay(10);
  sensorValue5 = analogRead (Pin0); //read value column 5
  delay(10);
  digitalWrite (dPin7, LOW); //turn row0 off
 
  msensorValue0 = map (sensorValue0, 0, 1023, 255, 0);
  msensorValue1 = map (sensorValue1, 0, 1023, 255, 0);
  msensorValue2 = map (sensorValue2, 0, 1023, 255, 0);
  msensorValue3 = map (sensorValue3, 0, 1023, 255, 0);
  msensorValue4 = map (sensorValue4, 0, 1023, 255, 0);
  msensorValue5 = map (sensorValue5, 0, 1023, 255, 0);
 
  Serial.print(msensorValue0);
  Serial.print(',');
  Serial.print(msensorValue1);
  Serial.print(',');
  Serial.print(msensorValue2);
  Serial.print(',');
  Serial.print(msensorValue3);
  Serial.print(',');
  Serial.print(msensorValue4);
  Serial.print(',');
  Serial.print(msensorValue5);
  Serial.print(',');
  
digitalWrite (dPin6, HIGH); //turn row0 on
  sensorValue0 = analogRead (Pin5); //read value column 0
  // wait 10 milliseconds before the next loop
  // for the analog-to-digital converter to settle
  // after the last reading:
  delay(10);  
  sensorValue1 = analogRead (Pin4); //read value column 1
  delay(10);
  sensorValue2 = analogRead (Pin3); //read value column 2
  delay(10);
  sensorValue3 = analogRead (Pin2); //read value column 3
  delay(10);
  sensorValue4 = analogRead (Pin1); //read value column 4
  delay(10);
  sensorValue5 = analogRead (Pin0); //read value column 5
  delay(10);
  digitalWrite (dPin6, LOW); //turn row0 off
 
  msensorValue0 = map (sensorValue0, 0, 1023, 255, 0);
  msensorValue1 = map (sensorValue1, 0, 1023, 255, 0);
  msensorValue2 = map (sensorValue2, 0, 1023, 255, 0);
  msensorValue3 = map (sensorValue3, 0, 1023, 255, 0);
  msensorValue4 = map (sensorValue4, 0, 1023, 255, 0);
  msensorValue5 = map (sensorValue5, 0, 1023, 255, 0);
 
 Serial.print(msensorValue0);
  Serial.print(',');
  Serial.print(msensorValue1);
  Serial.print(',');
  Serial.print(msensorValue2);
  Serial.print(',');
  Serial.print(msensorValue3);
  Serial.print(',');
  Serial.print(msensorValue4);
  Serial.print(',');
  Serial.print(msensorValue5);
  Serial.print(',');
 
digitalWrite (dPin5, HIGH); //turn row0 on
  sensorValue0 = analogRead (Pin5); //read value column 0
  // wait 10 milliseconds before the next loop
  // for the analog-to-digital converter to settle
  // after the last reading:
  delay(10);  
  sensorValue1 = analogRead (Pin4); //read value column 1
  delay(10);
  sensorValue2 = analogRead (Pin3); //read value column 2
  delay(10);
  sensorValue3 = analogRead (Pin2); //read value column 3
  delay(10);
  sensorValue4 = analogRead (Pin1); //read value column 4
  delay(10);
  sensorValue5 = analogRead (Pin0); //read value column 5
  delay(10);
  digitalWrite (dPin5, LOW); //turn row0 off
 
  msensorValue0 = map (sensorValue0, 0, 1023, 255, 0);
  msensorValue1 = map (sensorValue1, 0, 1023, 255, 0);
  msensorValue2 = map (sensorValue2, 0, 1023, 255, 0);
  msensorValue3 = map (sensorValue3, 0, 1023, 255, 0);
  msensorValue4 = map (sensorValue4, 0, 1023, 255, 0);
  msensorValue5 = map (sensorValue5, 0, 1023, 255, 0);
 
  Serial.print(msensorValue0);
  Serial.print(',');
  Serial.print(msensorValue1);
  Serial.print(',');
  Serial.print(msensorValue2);
  Serial.print(',');
  Serial.print(msensorValue3);
  Serial.print(',');
  Serial.print(msensorValue4);
  Serial.print(',');
  Serial.print(msensorValue5);
  Serial.print(',');
  
digitalWrite (dPin4, HIGH); //turn row0 on
  sensorValue0 = analogRead (Pin5); //read value column 0
  // wait 10 milliseconds before the next loop
  // for the analog-to-digital converter to settle
  // after the last reading:
  delay(10);  
  sensorValue1 = analogRead (Pin4); //read value column 1
  delay(10);
  sensorValue2 = analogRead (Pin3); //read value column 2
  delay(10);
  sensorValue3 = analogRead (Pin2); //read value column 3
  delay(10);
  sensorValue4 = analogRead (Pin1); //read value column 4
  delay(10);
  sensorValue5 = analogRead (Pin0); //read value column 5
  delay(10);
  digitalWrite (dPin4, LOW); //turn row0 off
 
  msensorValue0 = map (sensorValue0, 0, 1023, 255, 0);
  msensorValue1 = map (sensorValue1, 0, 1023, 255, 0);
  msensorValue2 = map (sensorValue2, 0, 1023, 255, 0);
  msensorValue3 = map (sensorValue3, 0, 1023, 255, 0);
  msensorValue4 = map (sensorValue4, 0, 1023, 255, 0);
  msensorValue5 = map (sensorValue5, 0, 1023, 255, 0);
 
 Serial.print(msensorValue0);
  Serial.print(',');
  Serial.print(msensorValue1);
  Serial.print(',');
  Serial.print(msensorValue2);
  Serial.print(',');
  Serial.print(msensorValue3);
  Serial.print(',');
  Serial.print(msensorValue4);
  Serial.print(',');
  Serial.print(msensorValue5);
  Serial.print(',');
  
digitalWrite (dPin3, HIGH); //turn row0 on
  sensorValue0 = analogRead (Pin5); //read value column 0
  // wait 10 milliseconds before the next loop
  // for the analog-to-digital converter to settle
  // after the last reading:
  delay(10);  
  sensorValue1 = analogRead (Pin4); //read value column 1
  delay(10);
  sensorValue2 = analogRead (Pin3); //read value column 2
  delay(10);
  sensorValue3 = analogRead (Pin2); //read value column 3
  delay(10);
  sensorValue4 = analogRead (Pin1); //read value column 4
  delay(10);
  sensorValue5 = analogRead (Pin0); //read value column 5
  delay(10);
  digitalWrite (dPin3, LOW); //turn row0 off
 
 msensorValue0 = map (sensorValue0, 0, 1023, 255, 0);
  msensorValue1 = map (sensorValue1, 0, 1023, 255, 0);
  msensorValue2 = map (sensorValue2, 0, 1023, 255, 0);
  msensorValue3 = map (sensorValue3, 0, 1023, 255, 0);
  msensorValue4 = map (sensorValue4, 0, 1023, 255, 0);
  msensorValue5 = map (sensorValue5, 0, 1023, 255, 0);
 
 Serial.print(msensorValue0);
  Serial.print(',');
  Serial.print(msensorValue1);
  Serial.print(',');
  Serial.print(msensorValue2);
  Serial.print(',');
  Serial.print(msensorValue3);
  Serial.print(',');
  Serial.print(msensorValue4);
  Serial.print(',');
  Serial.print(msensorValue5);
  Serial.print(',');
   
digitalWrite (dPin2, HIGH); //turn row0 on
  sensorValue0 = analogRead (Pin5); //read value column 0
  // wait 10 milliseconds before the next loop
  // for the analog-to-digital converter to settle
  // after the last reading:
  delay(10);  
  sensorValue1 = analogRead (Pin4); //read value column 1
  delay(10);
  sensorValue2 = analogRead (Pin3); //read value column 2
  delay(10);
  sensorValue3 = analogRead (Pin2); //read value column 3
  delay(10);
  sensorValue4 = analogRead (Pin1); //read value column 4
  delay(10);
  sensorValue5 = analogRead (Pin0); //read value column 5
  delay(10);
  digitalWrite (dPin2, LOW); //turn row0 off
 
  msensorValue0 = map (sensorValue0, 0, 1023, 255, 0);
  msensorValue1 = map (sensorValue1, 0, 1023, 255, 0);
  msensorValue2 = map (sensorValue2, 0, 1023, 255, 0);
  msensorValue3 = map (sensorValue3, 0, 1023, 255, 0);
  msensorValue4 = map (sensorValue4, 0, 1023, 255, 0);
  msensorValue5 = map (sensorValue5, 0, 1023, 255, 0);
 
 Serial.print(msensorValue0);
  Serial.print(',');
  Serial.print(msensorValue1);
  Serial.print(',');
  Serial.print(msensorValue2);
  Serial.print(',');
  Serial.print(msensorValue3);
  Serial.print(',');
  Serial.print(msensorValue4);
  Serial.print(',');
  Serial.println(msensorValue5);

}


Processing program

/*

Sensor orientation: corner 0,0 top left
*/
 
// Number of columns and rows in the grid
int cols = 8;
int rows = 6;
 
// Declare 2D array
float[] myArray = new float[cols*rows];
 

 import processing.serial.*;
 
 
 Serial myPort;
 
 void setup() {
 size(480, 360);
 
 
 // List all the available serial ports
 println(Serial.list());
 // I know that the first port in the serial list on my mac
 // is always my  Arduino, so I open Serial.list()[0].
 // Open whatever port is the one you're using.
 myPort = new Serial(this, Serial.list()[5], 9600);
 // don't generate a serialEvent() unless you get a newline character:
 myPort.bufferUntil('\n');
 }
 
 void draw() {
 
 }
 
 void serialEvent(Serial myPort) {
 // get the ASCII string:
 String inString = myPort.readStringUntil('\n');
 
 if (inString != null) {
 // trim off any whitespace:
 inString = trim(inString);
 // split the string on the commas and convert the
 // resulting substrings into an integer array:
 float[] myArray = float(split(inString, ","));
 // if the array has at least three elements, you know
 // you got the whole thing.  Put the numbers in the
 // color variables:
 println("Arrivato");
 if (myArray.length >=48) {
 
    for (int i = 0; i < cols; i++) {
      for (int j = 0; j < rows; j++) {
        stroke(255);
        println("valori i=" + i + "J="+ j + "val=" + int(myArray[(i*rows)+j]));
        fill(int(myArray[(i*rows)+j]));
        rect(i*60,j*60,60,60);
       }
    }
 
 }
 }
 }