Homework 14: Tweak the Logo

The Circuit

Parts List

Name	Quantity	Component
U1	1	Arduino Uno R3
Rpot1	1	250 kΩ Potentiometer

Parts List CSV

Schematics

Schematics pdf

Building the Circuit

This circuit was very simple with just one component to wire up. I connected the potentiometer and wen straight to programming. It was interesting to start working with processing to control things on my laptop. I got the IDE setup and began programming.

Programming

When programming, I ran into 2 main issues:

1. The image link didn’t work, which caused the program to crash, and I fixed by just finding another link to the image online, though it took me a little bit to figure out that that was the problem, until I noticed the error 403 in the debug log.
2. The bit buffer was being constantly overrun in the if statement, which meant that the program was unable to read and respond to the potentiometer. I could have fixed this by just increasing the delay when reading values, which solved the problem, but it still felt a little laggy and jittery, so I opted to turn the if statement to a while loop with the same 1 ms delay which felt much smoother and more responsive.

Code

Arduino Code

void setup() {
  // initialize serial communication
  Serial.begin(9600);
}

void loop() {
  // read the value of A0, divide by 4 and send it as a byte over the
  // serial connection
  Serial.write(analogRead(A0) / 4);
  delay(1);
}

Processing Code

// import the serial library
import processing.serial.*;

// create an instance of the serial library
Serial myPort;
PImage logo;
int bgcolor = 0;

void setup() {
  size(1, 1);
  surface.setResizable(true);
  // set the color mode to Hue/Saturation/Brightness
  colorMode(HSB, 255);

  // load the Arduino logo into the PImage instance
  // (I lost the link I used since I forgot to save the file)
  logo = loadImage("INSERT_IMAGE_LINK");

  // make the window the same size as the image
  surface.setSize(logo.width, logo.height);

  // give serial object the information it needs to communicate 
  myPort = new Serial(this, "COM3", 9600);
}

void draw() {
  // while there is information in the serial port
  while ( myPort.available() > 0) {
    // read the value and store it in a variable
    bgcolor = myPort.read();

    println(bgcolor);
  }

  // Draw the background using value from Serial Port
  background(bgcolor, 255, 255);

  // draw the Arduino logo
  image(logo, 0, 0);
}