As I wrote in the previous post I bought a 3-axis accelerometer and I want to plot its data using Processing but first .. how do I link Arduino with Processing ?

After around 30-35 minutes of try-fail and reading the docs/forums of both softwares I came up with the solution … I’ll link them using their common Serial library.

To make a proof-of-concept … lets write a simple Arduino code that controls the on-board LED based on 2 commands received from the Serial port … if it reads “1” the LED is ON and if it reads “0” the LED is OFF.

int pin_led = 13;
int reply = 0;

void setup()
{
  Serial.begin(9600);
  pinMode(pin_led, OUTPUT);
}

void loop()
{
  if (Serial.available() > 0)
  {
    reply = Serial.read();
    if (reply == '1')
    {
      digitalWrite(pin_led, HIGH);
    }
    else if (reply == '0')
    {
      digitalWrite(pin_led, LOW);
    }
  }
}

and then lets write a simple Processing code that sends “1” and “0” with a small delay :

import processing.serial.*;
import cc.arduino.*;

Serial serial_port;

void setup()
{
  serial_port = new Serial(this, Serial.list()[0], 9600);
}


void draw()
{
  serial_port.write('1');
  delay(400);
  serial_port.write('0');
  delay(400);
}

After you upload the Arduino code to the Arduino board and you run Processing code you should see the on-board LED blinking 🙂 Simple, huh?