Basic Processing to Arduino Communications
Friday, February 20th, 2009Finally sat down and figured out how to send some basic signals via serial from Processing to an Arduino. For this example I was just looking for basic functionality, so I settled for a simple way to turn a LED on and off. It’s also mostly sample code gathered from the Internet.
The Processing code creates a small black square on the screen. When the mouse cursor is moved over the square, it changes color to yellow and sends a “H” over serial to the Arduino. While the Arduino detects a “H” on serial it will light the LED.
Here’s a video of it in action and describing how to get started.
Basic Processing to Arduino Communications from Morgellon on Vimeo.
- Download Processing
http://processing.org/download/index.html
- Download Arduino to Processing Library
http://www.arduino.cc/playground/Interfacing/Processing
Now that you’ve gotten all the files installed and in their proper places, try out my test code I used in the video.
Arduino Code (Download here)
// Read data from the serial port and turn ON or OFF a light depending on the value
char val; //Data received from the serial port
int ledPin = 13; //Set value ledPin to pin 13
void setup(){
pinMode(ledPin, OUTPUT); //Sets pin as OUTPUT
Serial.begin(9600); //Start serial communication at 9600bps
}
void loop(){
if (Serial.available()){ //If data is available to read,
val = Serial.read(); //read it and store it as val
}
if (val == ‘H’){ //If H is recieved
digitalWrite(ledPin, HIGH); //turn ON light
} else {
digitalWrite(ledPin, LOW); //If not leave light OFF
}
delay(25);
}
Processing Code(Download here)
//Check if the mouse is over a rectangle and write the status to the serial port
import processing.serial.*;
import cc.arduino.*;
Serial port; //Create object from Serial class
void setup() {
size(200, 200);
noStroke();
frameRate(10);
//Open the port that the board is connected to and use the same speed (9600bps)
port = new Serial(this, Serial.list()[0], 9600);
}
void draw() {
background (255);
if (mouseOverRect() == true) { //If mouse if over square
fill(242, 204, 47); //change color
port.write(’H'); //send H to serial port
} else { //If mouse is NOT over square
fill(0); //change color
port.write(’L'); //send L to serial port
}
rect(50, 50, 100, 100); //Draws the square
}
boolean mouseOverRect() { //Tests if mouse is over square
return ((mouseX >= 50) && (mouseX <= 150) && (mouseY >= 50) && (mouseY <= 150));
}
