Description
Using Arduino Uno with FSR and Processing, I was able to build an pressure visualization. However, the process was very painful because the serial communication was very foreign to me, and I still don't think mine is working properly. I initially designed a wooden block building indicator based on FSR input. However, it turns out that the FSR was not a weight sensor to speak but a force sensor. I had trouble with mapping the output of sensors to the size of the ball in visualization too. My serial monitor was kind of speeding up crazy, so I am not sure processing is getting the input as it supposed to be. I tried with refreshrate on processing and adding delay on Arduino code, but nothing really worked.
Also, I was trying to make a visualization showing overlapped pictures in response to the FSR value, but the processing yielded a lot of JAVA warnings and runtime error, so I dropped it. I will try this personally later.
Components Used
1- Arduino Uno
1- LED
2- Resistors
1- Breadboard
1- FSR
Code
- Processing code:
/*
* Arduino Ball Paint
* (Arduino Ball, modified 2008)
* ----------------------
*
* Draw balls randomly on the screen, size controlled by a device
* on a serial port. Press space bar to clear screen, or any
* other key to generate fixed-size random balls.
*
* Receives an ASCII number over the serial port,
* terminated with a carriage return (ascii 13) then newline (10).
*
* This matches what Arduino's " Serial.println(val)" function
* puts out.
*
* Created 25 October 2006
* copyleft 2006 Tod E. Kurt <tod@todbot.com
* http://todbot.com/
*/
import processing.serial.*;
// Change this to the portname your Arduino board
String portname = "/dev/tty.usbmodem1421"; // or "COM5"
Serial port;
String buf="";
int cr = 13; // ASCII return == 13
int lf = 10; // ASCII linefeed == 10
// Declaring a variable of type PImage
//PImage daniel;
//PImage daniel2;
void setup() {
// size(800,600);
frameRate(50);
smooth();
background(40,40,40);
noStroke();
port = new Serial(this, portname, 9600);
port.bufferUntil('\n');
size(400,400);
}
void draw() {
// background(0);
// // Draw the image to the screen at coordinate (0,0)
// // Make a new instance of a PImage by loading an image file
// daniel = loadImage("1.jpg");
// daniel2 = loadImage("2.jpg");
// background(daniel2);
// tint(255, val/100);
// image(daniel,0,0);
}
void keyPressed() {
if(key == ' ') {
background(40,40,40); // erase screen
}
else {
// int x = int(random(0,width));
// int y = int(random(0,height));
int x = int(random(100,width-100));
int y = int(random(100,height-100));
drawball(x,y,20);
}
}
// draw balls
void drawball(int x, int y, int r) {
for (int i=0; i<100; i++ ) {
fill(255-r,r,255-i);
ellipse(x,y,r,r);
}
}
// called whenever serial data arrives
void serialEvent(Serial port) {
String c = port.readStringUntil(lf);
// if (c != lf && c != cr) {
// buf += char(c);
// }
if (c != null) {
int val = int(trim(c));
println("val="+val);
if (val>1000) {
val = val/2;
}
// int x = int(random(0,width));
// int y = int(random(0,height));
int x = int(random(100,width-100));
int y = int(random(100,height-100));
drawball(x,y,val/2);
buf = "";
background(40,40,40); // erase screen
}
}
- Arduino Code:
int FSRPin = 0; // select the input pin for the potentiometer
int ledPin = 13; // select the pin for the LED
int val = 0; // variable to store the value coming from the sensor
void setup() {
pinMode(ledPin, OUTPUT); // declare the ledPin as an OUTPUT
Serial.begin(9600);
}
void loop() {
val = analogRead(FSRPin)/4; // read the value from the sensor
analogWrite(ledPin, val); // turn the ledPin on
// delay(val); // stop the program for some time
// digitalWrite(ledPin, LOW); // turn the ledPin off
// delay(val); // stop the program for some time
// map(val, 1, 10000, 0, 100);
Serial.println(val);
delay(FSRPin);
Serial.println('\n');
}
Video
http://youtu.be/Go_9GWe4HhI
