# Ferrofluid Art Display

## Overview

Katy

### Team Members

• Todd H. Poole (Mechanical Engineering & Electrical Engineering, Class of 2010)
• Katy Powers (Mechanical Engineering, Class of 2010)
• Max Willer (Material Science and Engineering, Class of 2011)

## Mechanical Design

Todd An evolution of concepts. -Early sketches --Pros & Cons Decision of

Max

## Code

The code for the display setup consists of a GUI on the PC allowing the user to select which solenoids to turn on and off and code on the PIC to control the solenoids.

### Processing

Screenshot of User Interface. Green circles represent solenoids that are up while blue circles represent solenoids that are down.

The PC side of the user interface was created with Processing, an open source programming environment with many options for interesting visual display. This code creates a display of circles arranged in the same way as the solenoids in our hardware, which will change from blue to green when clicked and output a character via RS232 to the PIC.

```//Katy Powers
//3/11/2010
//ME 333 Ferrofluid Art GUI
//Lots of code taken from processing website and previous ME 333 labs..thanks!

import processing.serial.*;
Serial[] myPorts = new Serial[1];

//setup parameters for hexagonal array
//cx,cy define center position, rc is circle radius, sp is how far apart they are
int cx = 250;
int cy = 250;
int rc = 50;
int sp = 10;

//circleX and circleY store center locations of every circle in array
//solenoidON stores state of solenoid
//chararr stores characters corresponding to each solenoid
int[] circleX = {cx, cx + rc + sp,cx + 2*(rc + sp),cx - (rc + sp),cx - 2*(rc + sp),cx + rc/2 + sp/2,
cx + 3*rc/2 + 3*sp/2,cx - (rc/2 + sp/2),cx - (3*rc/2 + 3*sp/2),cx,cx+rc+sp, cx - (rc+sp),
cx + rc/2 + sp/2, cx + 3*rc/2 + 3*sp/2,cx - (rc/2 + sp/2),cx - (3*rc/2 + 3*sp/2),cx,
cx + rc + sp,cx-(rc + sp)};

int[] circleY = {cy,cy,cy,cy,cy,cy + rc +sp,cy + rc +sp,cy + rc +sp,cy + rc +sp,cy + 2*(rc+sp),
cy + 2*(rc+sp), cy + 2*(rc+sp),cy - (rc +sp),cy - (rc +sp),cy - (rc +sp),cy - (rc +sp),
cy - 2*(rc+sp),cy - 2*(rc+sp),cy - 2*(rc+sp)};

int[] solenoidON = new int[19];
char[] chararr = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s'};
PFont font;
PFont smallfont;

void setup()
{
InitSerial();
background(0);
size(500,500);
textAlign(CENTER);
for (int i = 0; i < 19; i = i+1){ //zero array of solenoid values, mouse state data
solenoidON[i] = 0;
}
rectMode(CENTER);
}

void draw()
{
fill(0,0,255);
textFont(font, 48);
text("Ferrofluid Art", cx, cy-200);
textFont(smallfont, 16);
text("Click a circle to make patterns in the Ferrofluid", cx, cy + 200);
hexagon(cx,cy,rc,sp, solenoidON);

}

void hexagon(int cx, int cy, int rc, int sp, int[] sols) //draws hexagon of cirlces
{
for (int i = 0; i < 19; i = i+1){
if(sols[i] == 0) {fill(0,0,255);}
else {fill(0,255,0);}
ellipse(circleX[i], circleY[i], rc, rc);
}

}

void mousePressed() //executes when mouse is pressed, much like an interrupt routine
{
float disX, disY;
for (int i = 0; i < 19; i = i+1){ //see where mouse is
disX = circleX[i] - mouseX;
disY = circleY[i] - mouseY;
if(sqrt(sq(disX) + sq(disY)) < rc/2 ) { //if mouse is in circle, toggle state and send character
solenoidON[i] = 1 - solenoidON[i];
myPorts[0].write(chararr[i]);
println(chararr[i]); //to debug
}
}
}
```

### PIC

The PIC side of the code runs an infinite while loop, executing an interrupt routine every time a character is received from the RS232. The PIC then updates the state of all the solenoids.

Max

Todd