Hey,
the code underneath is to send a value from processing to arduino (In this case angular degrees for a servo)

processing writes  :      port.write(spos + "a");
and Arduino gets that and uses switch... case to write it to a servo.
when you write : port.write(spos + "b");
it will write to an other servo.

I want to use this method for a large Serial communication and i need 24 "letters"

in my processing version it would look something like that:

char[] Order = {"a","b","c",..and so on ....,"v","w","x"};

and than :
port.write(pos + Order[i]);

but that doesn't work because I can't change strings into char.  "a" is a string and 'a' is a char ( as far I understood)
I did the array with chars {'a','b','c'.......};  but my servos didn't even twitch......
I tried it with the simple >>>port.write(spos + "b"); <<<<<  method and everything worked fine, so it needs to be something wrong with the array.

has someone any helpful suggestions?
I am really confused it think

Thank you very much !!!!


P.S.  that is not my code down there, but I thought it is easier to see that little code than my gigantic and confusing code.


 

1. /**
    * Servocontrol (derived from processing Mouse 1D example.)
    *
    * Updated 24 November 2007
    */
   
   
   // Use the included processing code serial library
   import processing.serial.*;       
   
   
   int gx = 15;
   int gy = 35;
   int spos=90;
   
   float leftColor = 0.0;
   float rightColor = 0.0;
   Serial port;                         // The serial port
   
   
   
   void setup()
   {
     size(720, 720);
     colorMode(RGB, 1.0);
     noStroke();
     rectMode(CENTER);
     frameRate(100);
   
     println(Serial.list()); // List COM-ports
   
     //select second com-port from the list
     port = new Serial(this, Serial.list()[1], 19200);
   }
   
   void draw()
   {
     background(0.0);
     update(mouseX);
     fill(mouseX/4);
     rect(150, 320, gx*2, gx*2);
     fill(180 - (mouseX/4));
     rect(450, 320, gy*2, gy*2);
   }
   
   void update(int x)
   {
     //Calculate servo postion from mouseX
     spos= x/4;
   
     //Output the servo position ( from 0 to 180)
     port.write(spos + "a");
   
   
   
     // Just some graphics
     leftColor = -0.002 * x/2 + 0.06;
     rightColor =  0.002 * x/2 + 0.06;
   
     gx = x/2;
     gy = 100-x/2;
   
   }
   
   
2. 
   //    Arduino code
   //
   //#include <Servo.h>
   //
   ////initialize all servos.
   //Servo servo1; Servo servo2;
   //
   //
   //void setup() {
   //
   //
   //    servo1.attach(3);
   //    servo2.attach(4);
   //
   //       servo1.write(100);
   //       servo2.write(170);
   //       delay(7000);
   //
   //
   //   
   //  Serial.begin(19200);
   //  Serial.println("Ready");
   //
   //}
   //
   //void loop() {
   //
   //  static int v = 0;
   //
   //  if ( Serial.available()) {
   //    char ch = Serial.read();
   //
   //    switch(ch) {
   //    case '0'...'9':
   //      v = v * 10 + ch - '0';
   //      break;
   //    case 'a':
   //      servo1.write(v);
   //      //Serial.print("a = ");
   //      //Serial.println(v);       
   //      v = 0;
   //      break;
   //    case 'b':
   //      servo2.write(180-v);
   //
   //
   //      //Serial.print("b = ");
   //      //Serial.println(v);
   //      v = 0;
   //      break;
   //    case 'c':
   //     // servo3.write(v);
   //      //Serial.print("c = ");
   //      //Serial.println(v);
   //      v = 0;
   //      break;
   //    case 'd':
   //      //servo4.write(v);
   //      //Serial.print("d = ");
   //      //Serial.println(v);
   //      v = 0;
   //      break;
   //    }
   //  }
   //
   //  //  Servo::refresh();
   //
   //}