Dots and Dashes with FSR

For this lab, I chose to take a modern approach to Morse Code and where the input signals come from. For my project, the dots come from keyboard inputs and the dashes come from FSR presses and together, you get a visual of the dots and spaces for the dashes. The blue LED also flashes in accordance with the FSR presses.

Components:

  • Arduino Uno
  • Breadboard
  • 1 force sensor
  • 1 220Ω resistors
  • 1 10Ω resistor
  •  wires

 

Arduino code #1:

int photocellPin = 0; // select the input pin for the potentiometer
int fsrPin =11;
int bPin = 11; // select the pin for the LED
 
int fsrVal;
int photocellVal; // variable to store the value coming from the sensor
 
int counter;
 
int THRESHOLD = 500;
 
void setup() {
 photocellVal = 0;
 fsrVal = 0;
 counter = 0; 
 Serial.begin(9600);
}
 
void loop() {
 fsrVal = analogRead(fsrPin); // read the value from the sensor, between 0 - 1024
 
 analogWrite(bPin, fsrVal/4);
 
 photocellVal = analogRead(photocellPin);
 
 if(photocellVal>THRESHOLD)
 {
 analogWrite(bPin, photocellVal/4);
 if(counter%300==0)
 {
// Serial.print(photocellVal);
 Serial.print("1");
 }
 }
 else
 {
 analogWrite(bPin, 0);
 if(counter%300==0)
 {
 Serial.print("0");
 }
 }
 
 counter++;
}

 

Processing code:

adapted from :http://courses.ischool.berkeley.edu/i262/s13/content/stlim/lab-submission-4-photocell-and-fsr?destination=node%2F909

import processing.serial.*;
 
// Change this to the portname your Arduino board
String portname = "/dev/tty.usbmodem1411";
Serial port;
String buf="";
int cr = 13; // ASCII return == 13
int lf = 10; // ASCII linefeed == 10
 
int radius = 50;
int gapX = 1;
int gapY = 3;
int windowX = 1000;
int windowY = 720;
int marginX = 40;
int marginY = 40;
int x = marginX;
int y = marginY;
 
boolean gap = false;
boolean init = true;
 
void setup() {
 size(1200, 720);
 frameRate(10);
 smooth();
 background(255, 200, 200);
 noStroke();
 port = new Serial(this, portname, 9600); 
}
void draw() {
}
 
void keyPressed() {
 if(key == ' ') {
 background(40,40,40); // erase screen
 }
 else {
 int x = int(random(0,width));
 int y = int(random(0,height));
 drawball();
 }
}
 
// draw balls
void drawball() {
 ellipse(x,y,radius,radius);
 x+=3;
// x += 2*radius + gapX;
 
 if(x>windowX-marginX) {
 x = marginX;
 y += 2*radius + gapY;
 }
}
// called whenever serial data arrives
void serialEvent(Serial p) {
 int serialVal = 0;
 int c = port.read();
 // called whenever serial data arrives
 if (c != lf && c != cr) {
 buf += char(c);
 }
 if (c == lf) {
 serialVal = int(buf);
 println("val="+serialVal); 
 buf = ""; 
 }

if(serialVal==0 && init) {
 
 }
 else if(serialVal == 0) {
 if(!gap) {
 x += 2*radius + gapX;
 }
 
 gap = true;
 }
 else {
 init = false;
 gap = false;
 drawball();
 x+=radius/5;
 }
}

 

Dots & Dashes

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