Arduino to Processing Data Transmission

Hey everyone,

I'm using Arduino to send values to Processing so that it can communicate via OSC protocol with the Wekinator application. The issue I'm having right now is that the speed at which Processing is transmitting data is EXTREMELY slow. It looks like it's only sending a couple of numbers per second. Any idea how I can fix that? I'll copy both my Arduino code and my Processing code underneath.

Thank you for your help in advance.

#include "I2Cdev.h"
#include "MPU6050.h"
#include "Wire.h"

MPU6050 accelgyro;

int16_t ax, ay, az;
int16_t gx, gy, gz;

void setup() {

  // join I2C bus (I2Cdev library doesn't do this automatically)
  Fastwire::setup(400, true);


void gyro() {

  accelgyro.getMotion6(&ax, &ay, &az, &gx, &gy, &gz);
  Serial.print(ax, DEC); 
  Serial.print(ay, DEC); 

void loop() {

import processing.serial.*;
import controlP5.*;
import java.util.*;
import oscP5.*;
import netP5.*;

//Objects for display:
ControlP5 cp5;
PFont fBig;
CColor defaultColor;

//Serial port info:
int end = 10;    // the number 10 is ASCII for linefeed (end of serial.println), later we will look for this to break up individual messages
String serial;   // declare a new string called 'serial' . A string is a sequence of characters (data type know as "char")
int numPorts = 0;
Serial myPort;  // The serial port
boolean gettingData = false; //True if we've selected a port to read from

//Objects for sending OSC
OscP5 oscP5;
NetAddress dest;

int numFeatures = 0;
String featureString = "";

void setup() {
  size(300, 250);

  //Set up display
  cp5 = new ControlP5(this);
  textAlign(LEFT, CENTER);
  fBig = createFont("Arial", 12);

  //Populate serial port options:
  List l = Arrays.asList(Serial.list());
  numPorts = l.size();
  cp5.addScrollableList("Port") //Create drop-down menu
     .setPosition(10, 60)
     .setSize(200, 100)
  defaultColor = cp5.getColor();
  //Set up OSC:
  oscP5 = new OscP5(this,9000); //This port isn't important (we're not receiving OSC)
  dest = new NetAddress("",6448); //Send to port 6448

//Called when new port (n-th) selected in drop-down
void Port(int n) {
 // println(n, cp5.get(ScrollableList.class, "Port").getItem(n));
  CColor c = new CColor();
  //Color all non-selected ports the default color in drop-down list
  for (int i = 0; i < numPorts; i++) {
      cp5.get(ScrollableList.class, "Port").getItem(i).put("color", defaultColor);
  //Color the selected item red in drop-down list
  cp5.get(ScrollableList.class, "Port").getItem(n).put("color", c);
  //If we were previously receiving on a port, stop receiving
  if (gettingData) {
  //Finally, select new port:
  myPort = new Serial(this, Serial.list()[n], 115200); //Using 115200 baud rate
  myPort.clear(); //Throw out first reading, in case we're mid-feature vector
  gettingData = true;
  serial = null; //Initialise serial string
  numFeatures = 0;

//Called in a loop at frame rate (100 Hz)
void draw() {
  text("Serial to OSC by Rebecca Fiebrink", 10, 10);
  text("Select serial port:", 10, 40);
  text("Sending " + numFeatures + " values to port 6448, message /wek/inputs", 10, 180); 
  text("Feature values:", 10, 200);
  text(featureString, 25, 220);

  if (gettingData) {

//Parses serial data to get button & accel values, also buffers accels if we're in button-segmented mode
void getData() {
  while (myPort.available() > 0 ) { 
    serial = myPort.readStringUntil(end);
  if (serial != null) {  //if the string is not empty, print the following
    /*  Note: the split function used below is not necessary if sending only a single variable. However, it is useful for parsing (separating) messages when
        reading from multiple inputs in Arduino. Below is example code for an Arduino sketch
      String[] a = split(serial, ',');  //a new array (called 'a') that stores values into separate cells (separated by commas specified in your Arduino program)
      numFeatures = a.length;

void sendFeatures(String[] s) {
  OscMessage msg = new OscMessage("/wek/inputs");
  StringBuilder sb = new StringBuilder();
  try {
    for (int i = 0; i < s.length; i++) {
      float f = Float.parseFloat(s[i]); 
      sb.append(String.format("%.2f", f)).append(" ");
    oscP5.send(msg, dest);
    featureString = sb.toString();
  } catch (Exception ex) {
     println("Encountered exception parsing string: " + ex); 


How is this an Arduino problem?
Is the data from the Arduino slow?

Thanks.. Tom.... :smiley: :+1: :coffee: :australia:

Thank you Tom for your insightful comment.