Week 14. Interface and Application Programming

Before the Start

Introduction 🖊

This week belongs to programming. Bas and Bente will introduce different ways of integrating interfaces with Arduino and our Hello World boards.

Fab Assignments 📚

My Goals 🎯

Project Management

How I’m going to organize my work during the week.

Task Time Day
Research 3h 3, may
Group Assignment 6h 4, May
Individual Assignment 4h 10, May
Documentation 1h 10, May

Files 📂

Name Description Link
File 0 Saliva = In this code the LED blinks every time the sensor reads the threshold on 530 Link
File 1 Saliva = Processing Interfacing Link

Research

I am working on my final project with a Heart Beat sensor. I did research the following websites in order to make the assignment and test the input for my final project:

And I watched the following Youtube Video tutorials:

During the Process

Results 🖖

week14-0

Group Assignment Process 🏊‍♀️ 🏊🏾 🏊🏽‍♀️

Bas

Attached are the tips and codes we used together with Bas during his introduction to the topic. More info can be found on his website.

He learned us how to integrate Processing with Arduino.

Drawing a line and a Circle

line(0,0,100,100);
circle(20,40,20); 

week14-1

If you code this, everything is black because first processing draws the circule and secondly the back on top of it:

void setup(){
size(800,600);
}

void draw(){
circle(300,500,300);
background(0,0,0);
}

week14-2

If you code this, you get the circle because it first makes the background and then the circle:

void setup(){
size(800,600);
}

void draw(){
background(0,0,0);
circle(300,500,300);
}

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Individual Assignment Process 🏊‍♀️

Thanks to the lessons given by Bas and Bente, I found interest in learning more about processing and its design possibilities.

I started the individual assignment having fun with this software, playing around with the tutorials available on its website.

Then, I moved to research how I could use this new learning for my final project. I tested the heartbeat sensor using Processing to show in the screen the heartbeats.

Processing + Final Project 🧘🏼✨🌸

The development was easy because I could follow a few tutorials online which explain ways to integrate processing with the sensor. These are a few videos that I checked for their development:

The code used with Arduino is the following. I just needed to change the const int OUTPUT_TYPE from SERIAL_PLOTTER to PROCESSING_VISUALIZER:

// "Saliva" code by Paola Zanchetta - 29/05/2022
// Interactive system mind-plants
// In this code the LED blinks every time the sensor reads the threshold on 530 

const int OUTPUT_TYPE = PROCESSING_VISUALIZER; 

// Define PINs, change for PCB

int PulseSensor = 0; // INPUT = A0, Heart Sensor
int LED = 13; // OUTPUT = 13, LED to check if it is working

// Define Global Variables

int Signal;                      // Holds the incoming raw data. Signal value can range from 0-1024
int Threshold = 530;            // Determine which Signal to "count as a beat", and which to ingore.


// The SetUp Function:
void setup() {

pinMode(LED,OUTPUT);         // LED that will blink to my heartbeat
Serial.begin(9600);         // Serial Communication at certain speed

}


// The Main Loop Function
void loop() {

Signal = analogRead(PulseSensor);  // Reads the PulseSensor's value and assigns this value to the "Signal" variable

Serial.println(Signal);           // Send the Signal value to Serial Plotter


if(Signal > Threshold){           // If the signal is above "530", then "turn-on" Arduino's on-Board LED
    digitalWrite(LED,HIGH);
    
} else {
    digitalWrite(LED,LOW);          //  Else, the sigal must be below "530", so "turn-off" this LED
}


delay(5);

}

I could find the code to work with Processing here:

import processing.serial.*;  // serial library lets us talk to Arduino
PFont font;
PFont portsFont;
Scrollbar scaleBar;

Serial port;

int Sensor;      // HOLDS PULSE SENSOR DATA FROM ARDUINO
int IBI;         // HOLDS TIME BETWEN HEARTBEATS FROM ARDUINO
int BPM;         // HOLDS HEART RATE VALUE FROM ARDUINO
int[] RawY;      // HOLDS HEARTBEAT WAVEFORM DATA BEFORE SCALING
int[] ScaledY;   // USED TO POSITION SCALED HEARTBEAT WAVEFORM
int[] rate;      // USED TO POSITION BPM DATA WAVEFORM
float zoom;      // USED WHEN SCALING PULSE WAVEFORM TO PULSE WINDOW
float offset;    // USED WHEN SCALING PULSE WAVEFORM TO PULSE WINDOW
color eggshell = color(255, 253, 248);
int heart = 0;   // This variable times the heart image 'pulse' on screen
//  THESE VARIABLES DETERMINE THE SIZE OF THE DATA WINDOWS
int PulseWindowWidth = 490;
int PulseWindowHeight = 512;
int BPMWindowWidth = 180;
int BPMWindowHeight = 340;
boolean beat = false;    // set when a heart beat is detected, then cleared when the BPM graph is advanced

// SERIAL PORT STUFF TO HELP YOU FIND THE CORRECT SERIAL PORT
String serialPort;
String[] serialPorts = new String[Serial.list().length];
boolean serialPortFound = false;
Radio[] button = new Radio[Serial.list().length*2];
int numPorts = serialPorts.length;
boolean refreshPorts = false;

void setup() {
size(700, 600);  // Stage size
frameRate(100);
font = loadFont("Arial-BoldMT-24.vlw");
textFont(font);
textAlign(CENTER);
rectMode(CENTER);
ellipseMode(CENTER);
// Scrollbar constructor inputs: x,y,width,height,minVal,maxVal
scaleBar = new Scrollbar (400, 575, 180, 12, 0.5, 1.0);  // set parameters for the scale bar
RawY = new int[PulseWindowWidth];          // initialize raw pulse waveform array
ScaledY = new int[PulseWindowWidth];       // initialize scaled pulse waveform array
rate = new int [BPMWindowWidth];           // initialize BPM waveform array
zoom = 0.75;                               // initialize scale of heartbeat window

// set the visualizer lines to 0
resetDataTraces();

background(0);
// DRAW OUT THE PULSE WINDOW AND BPM WINDOW RECTANGLES
drawDataWindows();
drawHeart();

// GO FIND THE ARDUINO
fill(eggshell);
text("Select Your Serial Port",245,30);
listAvailablePorts();

}

void draw() {
if(serialPortFound){
// ONLY RUN THE VISUALIZER AFTER THE PORT IS CONNECTED
background(0);
noStroke();
drawDataWindows();
drawPulseWaveform();
drawBPMwaveform();
drawHeart();
// PRINT THE DATA AND VARIABLE VALUES
fill(eggshell);                                       // get ready to print text
text("Pulse Sensor Amped Visualizer v1.5",245,30);    // tell them what you are
text("IBI " + IBI + "mS",600,585);                    // print the time between heartbeats in mS
text(BPM + " BPM",600,200);                           // print the Beats Per Minute
text("Pulse Window Scale " + nf(zoom,1,2), 150, 585); // show the current scale of Pulse Window

//  DO THE SCROLLBAR THINGS
scaleBar.update (mouseX, mouseY);
scaleBar.display();

} else { // SCAN BUTTONS TO FIND THE SERIAL PORT

autoScanPorts();

if(refreshPorts){
    refreshPorts = false;
    drawDataWindows();
    drawHeart();
    listAvailablePorts();
}

for(int i=0; i<numPorts+1; i++){
    button[i].overRadio(mouseX,mouseY);
    button[i].displayRadio();
}

}

}  //end of draw loop


void drawDataWindows(){
    // DRAW OUT THE PULSE WINDOW AND BPM WINDOW RECTANGLES
    noStroke();
    fill(eggshell);  // color for the window background
    rect(255,height/2,PulseWindowWidth,PulseWindowHeight);
    rect(600,385,BPMWindowWidth,BPMWindowHeight);
}

void drawPulseWaveform(){
// DRAW THE PULSE WAVEFORM
// prepare pulse data points
RawY[RawY.length-1] = (1023 - Sensor) - 212;   // place the new raw datapoint at the end of the array
zoom = scaleBar.getPos();                      // get current waveform scale value
offset = map(zoom,0.5,1,150,0);                // calculate the offset needed at this scale
for (int i = 0; i < RawY.length-1; i++) {      // move the pulse waveform by
    RawY[i] = RawY[i+1];                         // shifting all raw datapoints one pixel left
    float dummy = RawY[i] * zoom + offset;       // adjust the raw data to the selected scale
    ScaledY[i] = constrain(int(dummy),44,556);   // transfer the raw data array to the scaled array
}
stroke(250,0,0);                               // red is a good color for the pulse waveform
noFill();
beginShape();                                  // using beginShape() renders fast
for (int x = 1; x < ScaledY.length-1; x++) {
    vertex(x+10, ScaledY[x]);                    //draw a line connecting the data points
}
endShape();
}

void drawBPMwaveform(){
// DRAW THE BPM WAVE FORM
// first, shift the BPM waveform over to fit then next data point only when a beat is found
if (beat == true){   // move the heart rate line over one pixel every time the heart beats
beat = false;      // clear beat flag (beat flag waset in serialEvent tab)
for (int i=0; i<rate.length-1; i++){
    rate[i] = rate[i+1];                  // shift the bpm Y coordinates over one pixel to the left
}
// then limit and scale the BPM value
BPM = min(BPM,200);                     // limit the highest BPM value to 200
float dummy = map(BPM,0,200,555,215);   // map it to the heart rate window Y
rate[rate.length-1] = int(dummy);       // set the rightmost pixel to the new data point value
}
// GRAPH THE HEART RATE WAVEFORM
stroke(250,0,0);                          // color of heart rate graph
strokeWeight(2);                          // thicker line is easier to read
noFill();
beginShape();
for (int i=0; i < rate.length-1; i++){    // variable 'i' will take the place of pixel x position
vertex(i+510, rate[i]);                 // display history of heart rate datapoints
}
endShape();
}

void drawHeart(){
// DRAW THE HEART AND MAYBE MAKE IT BEAT
    fill(250,0,0);
    stroke(250,0,0);
    // the 'heart' variable is set in serialEvent when arduino sees a beat happen
    heart--;                    // heart is used to time how long the heart graphic swells when your heart beats
    heart = max(heart,0);       // don't let the heart variable go into negative numbers
    if (heart > 0){             // if a beat happened recently,
    strokeWeight(8);          // make the heart big
    }
    smooth();   // draw the heart with two bezier curves
    bezier(width-100,50, width-20,-20, width,140, width-100,150);
    bezier(width-100,50, width-190,-20, width-200,140, width-100,150);
    strokeWeight(1);          // reset the strokeWeight for next time
}

void listAvailablePorts(){
println(Serial.list());    // print a list of available serial ports to the console
serialPorts = Serial.list();
fill(0);
textFont(font,16);
textAlign(LEFT);
// set a counter to list the ports backwards
int yPos = 0;
int xPos = 35;
for(int i=serialPorts.length-1; i>=0; i--){
    button[i] = new Radio(xPos, 95+(yPos*20),12,color(180),color(80),color(255),i,button);
    text(serialPorts[i],xPos+15, 100+(yPos*20));

    yPos++;
    if(yPos > height-30){
    yPos = 0; xPos+=200;
    }
}
int p = numPorts;
fill(233,0,0);
button[p] = new Radio(35, 95+(yPos*20),12,color(180),color(80),color(255),p,button);
    text("Refresh Serial Ports List",50, 100+(yPos*20));

textFont(font);
textAlign(CENTER);
}

void autoScanPorts(){
if(Serial.list().length != numPorts){
    if(Serial.list().length > numPorts){
    println("New Ports Opened!");
    int diff = Serial.list().length - numPorts;	// was serialPorts.length
    serialPorts = expand(serialPorts,diff);
    numPorts = Serial.list().length;
    }else if(Serial.list().length < numPorts){
    println("Some Ports Closed!");
    numPorts = Serial.list().length;
    }
    refreshPorts = true;
    return;
}
}

void resetDataTraces(){
for (int i=0; i<rate.length; i++){
    rate[i] = 555;      // Place BPM graph line at bottom of BPM Window
    }
for (int i=0; i<RawY.length; i++){
    RawY[i] = height/2; // initialize the pulse window data line to V/2
}
}

There are a couple of cool things that can be made while the sketch is running:

Attached the screen of what could be seen in the processing monitor + the Arduino set up:

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Retrospective 🤔

This week resulted on being lots of fun!. Probably the nicest part of learning about coding is being able to translate the data into something tangible: both by using outputs like we learned during the previous weeks, or by integrating the data into graphic visualizations.

I did test an example of how to integrate Processing and Arduino. Learning the basics: how to connect ports, and create a simple integration of the data. The outcome was very exciting and motivating.

I would like to work more on my future projects with the knowledge. I think it is a very powerful tool that can be used to transform complicated data into colorful and dynamic graphics which engage better with people.