L3G4200D and Processing

Hello! I am trying to create a graph of angular rate through my L3G4200D.

In Arduino I used this code (found on the net)

#include <Wire.h>

#define CTRL_REG1 0x20
#define CTRL_REG2 0x21
#define CTRL_REG3 0x22
#define CTRL_REG4 0x23

int Addr = 105;                 // I2C address of gyro
int x, y, z;

void setup(){
  Wire.begin();
  Serial.begin(9600);
  writeI2C(CTRL_REG1, 0x1F);    // Turn on all axes, disable power down
  writeI2C(CTRL_REG3, 0x08);    // Enable control ready signal
  writeI2C(CTRL_REG4, 0x80);    // Set scale (500 deg/sec)
  delay(100);                   // Wait to synchronize 
}

void loop(){
  getGyroValues();              // Get new values
  // In following Dividing by 114 reduces noise
  Serial.print("Raw X:");  Serial.print(x / 114);  
  Serial.print(" Raw Y:"); Serial.print(y / 114);
  Serial.print(" Raw Z:"); Serial.println(z / 114);
  delay(500);                   // Short delay between reads
}

void getGyroValues () {
  byte MSB, LSB;

  MSB = readI2C(0x29);
  LSB = readI2C(0x28);
  x = ((MSB << 8) | LSB);

  MSB = readI2C(0x2B);
  LSB = readI2C(0x2A);
  y = ((MSB << 8) | LSB);

  MSB = readI2C(0x2D);
  LSB = readI2C(0x2C);
  z = ((MSB << 8) | LSB);
}

int readI2C (byte regAddr) {
    Wire.beginTransmission(Addr);
    Wire.write(regAddr);                // Register address to read
    Wire.endTransmission();             // Terminate request
    Wire.requestFrom(Addr, 1);          // Read a byte
    while(!Wire.available()) { };       // Wait for receipt
    return(Wire.read());                // Get result
}

void writeI2C (byte regAddr, byte val) {
    Wire.beginTransmission(Addr);
    Wire.write(regAddr);
    Wire.write(val);
    Wire.endTransmission();
}

It works, but if I upload this code on Arduino, I don’t know how to use Firmata to make Arduino communicate with Precessing.
Any idea?
Thank you.

It works, but if I upload this code on Arduino, I don't know how to use Firmata to make Arduino communicate with Precessing.

You can't. You can use that sketch or you can use the Firmata sketch, but not both.

Board I2C / TWI pins
Uno, Ethernet A4 (SDA), A5 (SCL)
Mega2560 20 (SDA), 21 (SCL)
Leonardo 2 (SDA), 3 (SCL)
Due 20 (SDA), 21 (SCL), SDA1, SCL1