new code for the 16x4x3

an improved code,written by olaf. the main virtue of this one against the old one is that the multiplexing section is now "outputing" a string of input+i.d, so you could easily tag your inputs. there is however some decoding to be done on the max/msp side as shown on the foto below.
the 595 part is still credited to sebastian tomczak aka little scale.

// 16x4x3 www.openskinnerbox.blogspot.com , 2010



//Pin connected to ST_CP of 74HC595

int latchPin = 8;

//Pin connected to SH_CP of 74HC595

int clockPin = 12;

////Pin connected to DS of 74HC595

int dataPin = 11;

byte data1;

byte data2;

byte data3;

// ----------------------------- MUXES -------------------------------

const byte APin = 2;            // Pins for 4051-Control

const byte BPin = 3;            // ...

const byte CPin = 4;            // ...

byte row = 0;            // store bin code

byte r0 = 0;             // Input selection value...

byte r1 = 0;

byte r2 = 0;

byte count = 0;          // just a count

// -------------------------------------------------------------------

const byte numControls = 40;     // Amount of Knobs

const byte ctrlOffset = 1;      // start scanning at this Controller (min 1 !!!)

const byte hysteresis = 10;      // Hysteresis (0 = off)

byte analogInputPin;            // Pin for analog Input

int value;                      // read analog Input to here

int oldValue  [numControls];    // Value read last time

int lowerLimit[numControls];    // Hysteresis window

int upperLimit[numControls];    // ...

const byte startbyte = 254;     // data block indicators...

const byte stopbyte = 255;      // ...

byte lobyte = 0;                // 5 bit...

byte hibyte = 0;                // and the other 5 bit of the value

// ===================================================================

void setup()

{

  for (count=0; count// clear Hysteresis-Windows

  {

    lowerLimit[count] = 0;

    upperLimit[count] = lowerLimit[count] + hysteresis;

  }

// -------------SETUP ARDUINO-----------------

  pinMode(APin, OUTPUT);        // Set 4051-Control Pins as Outputs...

  pinMode(BPin, OUTPUT);

  pinMode(CPin, OUTPUT);

  digitalWrite(APin, LOW);      // set the 4051 to Input 0...

  digitalWrite(BPin, LOW);

  digitalWrite(CPin, LOW);

  

  pinMode(latchPin, OUTPUT);     // 595

  Serial.begin(57600);

// -------------------------------------------

}



// =====================================================================================

// ===================================== M A I N =======================================

// =====================================================================================

void loop()

{

  for (count=(ctrlOffset-1); count<(numControls+ctrlOffset-1); count++)

  {

    switch (count+1)

    {

//     case 29: break;        // following inputs are not connected, so don´t check them!

//      case 31: break;

//      case 40: break;

//      case 41: break;

      case 42: break;

      case 43: break;

      case 44: break;

      case 45: break;

      case 46: break;

      case 47: break;

      default:

      {

// -------------------- set the MUXES ---------------------

        row = count & 7;        // wrap count between 0 and 7

        r0 = row & 1;

        r1 = (row >> 1) & 1; 

        r2 = (row >> 2) & 1; 

        digitalWrite(APin, r0);       // set 4051 Input...

        digitalWrite(BPin, r1); 

        digitalWrite(CPin, r2);

// ---------------------------------------------------------



        analogInputPin = count >> 3;       // div. count by 8



        value = analogRead(analogInputPin);



        if ((value<=upperLimit[count]) && (value>=lowerLimit[count]))    // no change...

        { }                                                              // ... no operation.

        else 

        {                                               // Otherwise set new Hysteresis-window...

          if (value>upperLimit[count])

          {

            upperLimit[count] = value;

            lowerLimit[count] = upperLimit[count] - hysteresis;

          }

          else

          {

            lowerLimit[count] = value;

            upperLimit[count] = lowerLimit[count] + hysteresis;

          }



          lobyte = value >> 5;                          // ... split value...

          hibyte = value & 31;



          Serial.print(startbyte);                      // ... and send out a packet!

          Serial.print(count);

          Serial.print(lobyte);

          Serial.print(hibyte);

          Serial.print(stopbyte);





          delayMicroseconds(10000);

        }

      }

    }

  }



if(Serial.available() > 2) {

data1 = Serial.read();

data2 = Serial.read();

data3 = Serial.read();

digitalWrite(latchPin, 0);

shiftOut(dataPin, clockPin, data1);

shiftOut(dataPin, clockPin, data2);

shiftOut(dataPin, clockPin, data3);

digitalWrite(latchPin, 1);

}

}

void shiftOut(int myDataPin, int myClockPin, byte myDataOut) {

int i=0;

int pinState;

pinMode(myClockPin, OUTPUT);

pinMode(myDataPin, OUTPUT);

digitalWrite(myDataPin, 0);

digitalWrite(myClockPin, 0);

for (i=7; i>=0; i--) {

digitalWrite(myClockPin, 0);

if ( myDataOut & (1<pinState= 1;

}

else {

pinState= 0;

}

digitalWrite(myDataPin, pinState);

digitalWrite(myClockPin, 1);

digitalWrite(myDataPin, 0);

}

digitalWrite(myClockPin, 0);

}