Clickable Dot

We’ve tried drawing motion graphic, responding to mouse event, and controlling LED. So, we might as well combine these functions, draw a clickable dot, to control the LED!

Required Components

In this project, we need the following components.

It’s definitely convenient to buy a whole kit, here’s the link:

Name	ITEMS IN THIS KIT	LINK
Raphael Kit	337	Raphael Kit

You can also buy them separately from the links below.

COMPONENT INTRODUCTION	PURCHASE LINK
GPIO Extension Board	BUY
Breadboard	BUY
Jumper Wires	BUY
LED	BUY

Wiring

Sketch

import processing.io.*;
boolean state = false;
int ledPin = 17;

void setup() {
    GPIO.pinMode(ledPin, GPIO.OUTPUT);
    background(255);
}

void draw() {
    if (state == true) {
        GPIO.digitalWrite(ledPin, GPIO.LOW);
        fill(255, 0, 0);
    }else {
        GPIO.digitalWrite(ledPin, GPIO.HIGH);
        fill(155);
    }
    ellipse(width/2, height/2, width*0.75, height*0.75);
}

void mouseClicked() {
    //  toggles state:
    if (2*dist(mouseX,mouseY,width/2, height/2)<=width*0.75)
        {state = !state;}
}

How it works?

This project has a lot in common with Blinking Dot, the difference is that it puts the toggle state in the mouse event. This causes the LED to not blink automatically, but to light up and go off with a mouse click.

And in the mouseClicked() event, the dist() function is used to determine the position of the mouse at the time of the click, and the dot is considered clicked only if the distance between the mouse and the center of the dot is less than the radius.