title: Firmata servo control
body: <p>I am stuck on my project at the final part which is controlling a servo by reading xml feed and depending on the values it should turn several degrees. I am using a weather xml feed by yahoo which shows different wind speed attributes as speed, direction and etc. What i am doing is Im using only wind direction and speed in order to visualize it with LED's and and arrow for the direction. Everything works fine with the LED's , but when it comes to the servo I'm not quite sure what to do. It works alright with the Arduino sweeping example, but I use Firmata and i guess the code for it is a bit different. First I used standard Firmata to control the LED's but it wasn't good with the servo, so now Im using 2 arduino's one with Standard Firmata for the LEDs and one with Servo Firmata for the servo, noth assigned on different COM ports. Unfortunately when I try to program the servo it only gets faster or slower without being able to control the angle of it and when to stop. In arduino it works with their example, but in Firmata it seems that I can't adapt it so it does similar in Processing with Firmata. I've been stuck on this for 2 days already pls any help would be appreciated since I have to finish it by Monday </p>
  
  <p>here is the code :</p>
  
  <pre><code>import processing.serial.*;
  import cc.arduino.*;
  Arduino arduino, arduino2;
  
  
  
  final String URL   = "http://weather.yahooapis.com/forecastrss?w=27764362";
  final String WORD  = "yweather:wind";
  final String TOKEN = "\\W+";
  
  int ledPin = 13;
  int ledPin1 = 12;
  int ledPin2 = 8;
  int pos=0;
  void setup() {
  
    arduino = new Arduino(this, Arduino.list()[0], 57600);
    arduino2 = new Arduino(this, Arduino.list()[1], 57600);
    arduino.pinMode(ledPin, Arduino.OUTPUT);
    arduino.pinMode(ledPin1, Arduino.OUTPUT);
    arduino.pinMode(ledPin2, Arduino.OUTPUT);
    arduino2.pinMode (9, Arduino.OUTPUT);
  
    final String[] xml = loadStrings(URL);
  
    int idx = 0;
  
    for (; idx != xml.length; ++idx)
      if ( xml[idx].contains(WORD) )  break;
  
    if (idx == xml.length) {
      println("Not found");
      exit();
    }
  
    println("Index: " + idx);
    println(xml[idx]);
  
    final int[] info = int( xml[idx].split(TOKEN) );
    final int dir = info[6];
    final int spd = info[8];
    println("Speed: " + spd);
    println("Direction: " + dir);
  
    if (spd &lt; 5 ) {
      arduino.digitalWrite(ledPin, Arduino.LOW);
      arduino.digitalWrite(ledPin1, Arduino.LOW);
      arduino.digitalWrite(ledPin2, Arduino.LOW);
    }
    if (spd &gt;= 5 &amp;&amp; spd &lt;10) {
      arduino.digitalWrite(ledPin, Arduino.HIGH);
      arduino.digitalWrite(ledPin1, Arduino.LOW);
      arduino.digitalWrite(ledPin2, Arduino.LOW);
    } 
    if (spd &gt;= 10 &amp;&amp; spd &lt;= 15) {
      arduino.digitalWrite(ledPin, Arduino.HIGH);
      arduino.digitalWrite(ledPin1, Arduino.HIGH);
      arduino.digitalWrite(ledPin2, Arduino.LOW);
    } 
   if (spd &gt; 16) { 
      arduino.digitalWrite(ledPin, Arduino.HIGH);
      arduino.digitalWrite(ledPin1, Arduino.HIGH);
      arduino.digitalWrite(ledPin2, Arduino.HIGH);
    }
  println("3");
  
  
    if (dir &gt;= 10 &amp;&amp; dir &lt;= 25) { 
     println("4");
  
      arduino2.analogWrite(9, 90);              
      delay(1500);                       
  
    } 
    else if (dir &gt; 340 &amp;&amp; dir &lt;= 360) {
      println("Low speed");
  
  
   arduino2.analogWrite(9, 80);  //in this case 80 is controlling the speed, although I wanted to control the angle
      delay(1500);       
      arduino2.analogWrite(9, 120);      // same here       
      delay(1500);     
    println("5");
    }
  
  }
  </code></pre>
  
  <p>All those prinLn(1-5) are obviously just code checkers to see if there is something wrong with it, but i guess there isnt, its just that i cant control the angle or any other particular control over it other than it's speed, but it doesn't stop spinning till I unplug the usb most cases :) </p>
  
  <p>I guess i need to insert somewher this part of the arduino example to make it move properly :</p>
  
  <pre><code>void loop() 
  { 
    for(pos = 0; pos &lt; 180; pos += 1)  // goes from 0 degrees to 180 degrees 
    {                                  // in steps of 1 degree 
      myservo.write(pos);              // tell servo to go to position in variable 'pos' 
      delay(15);                       // waits 15ms for the servo to reach the position 
    } 
  </code></pre>
  
  <p>But not quite sure since i tried, but I might not have programmed it properly .</p>
  
  <p>Thanks!</p>