(School project) Problem writing code for a solar tracker (two servos ++)

Projects General Guidance
1

I don't know much C, but I am currently trying to make a solar tracker with an x-axis 360 degree continous servo on the bottom that follows light using two photoresistors and a y-axis 180 degree servo that can be controlled with a computer mouse.
(I found the instructions on various websites;
Mouse code: Arduino Playground - SingleServoExample
Original solar tracker code: http://thegeekbucketlist.wordpress.com/ )
I have connected the hardware and i have made both codes work seperatly. When i try to merge the codes, only the x servo works. However, when I switch places of the code within the void loop, only the y servo works (after running the code for processing ofcourse).
Can anyone help me fix this problem and help me write/write the code i need? I have tried for so many hours, and any help would be greatly appriciated.
Any help is very apriciated, also please let me know if you need more information in order to help me.
The (very untidy) code:

#include <Servo.h>

int ServoOut = 9;
int photoPinLeft = 0;
int photoPinRight = 5;
int LeftReading;
int RightReading;
int pos;
int tolerance = 100;

Servo servox; Servo servoy; 

void setup() {
  servoy.attach(16);  
  servox.attach(ServoOut);

  Serial.begin(9200);
}

void loop() {
LeftReading = analogRead(photoPinLeft);
RightReading = analogRead(photoPinRight);

Serial.print("Left Reading = ");
Serial.println(LeftReading);
Serial.print("Right Reading = ");
Serial.println(RightReading);

if(LeftReading > RightReading + tolerance)
{
pos = 58;
}
else if(LeftReading + tolerance < RightReading)
{
pos = 52;
}
else
{
pos = 55;
}

servox.write(pos);
delay(120);

  static int v = 0;

  if ( Serial.available()) {
    char ch = Serial.read();

    switch(ch) {
      case '0'...'9':
        v = v * 10 + ch - '0';
        break;
      case 's':
        servoy.write(v);
        v = 0;
        break;
        
    }
  }
}

And the processing code i use:

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()[0], 9200); 
}

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("s"+spos); 



  // 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

Judging by the Arduino sketch you posted, the servox is controlled automatically based on the light sensor inputs and you say that part is working. The servoy is controlled by a sequence of characters received over the serial port (from your Processing application, I suppose). You don't have any debug in the code to show whether you are receiving any input on the serial port or what value it is ending up writing to the servo, so I suggest you add some. For all we know, your Processing application is connecting to the wrong serial port and nothing is reaching the Arduino. Is the Y servo actually powered up and connected to pin 16? Is it a normal servo, not one modified for continuous rotation (which the X servo seems to be)?

Have you noticed that the Arduino is looking for a number followed by 's' and your Processing application is writing 's' followed by a number? At the end of the day it will probably work but it means the Arduino will only process each event at the start of the next event, which doesn't seem ideal; better to correct update() to write spos+"s".

3

PeterH:
Judging by the Arduino sketch you posted, the servox is controlled automatically based on the light sensor inputs and you say that part is working. The servoy is controlled by a sequence of characters received over the serial port (from your Processing application, I suppose).

Correct.

How do you suggest i add some debugs? ( I am a total noob, so any help is very appreciated). Are you thinking about adding "Serial.println("Ready");", and where?

The Y servo is working perfectly if i remove all the code in the void loop before "static int", or place it on top. If i place it on top of the "code for the X servo", the X servo stops working...

PeterH:
Have you noticed that the Arduino is looking for a number followed by 's' and your Processing application is writing 's' followed by a number? At the end of the day it will probably work but it means the Arduino will only process each event at the start of the next event, which doesn't seem ideal; better to correct update() to write spos+"s".

Are you talking about changing "update(mouseX)" to update("s"+spos)? Then i get the error:
The method update(int) in the type sketch_may22nd is not applicable for the arguments (String)