Heartrate Orb

For this assignment, I wanted to make something that had to do with a heartrate. During that time I was dealing with stressful situations and I want to somehow bring that back into my work.

I thought about this idea further as I looked into heartrate Arduino projects and realized that this interests also crosses with my fascination about diving. Specifically the dangers of diving. Keeping calm is one if not the most important thing to do while you're submerged in water meters down.

The end product

A strange piece of coral holding a sea creature egg was the concept. Placing your finger down onto a heart rate sensor with some pressure makes it so that the egg lights up according to your heartrate. Calculating the time between heartbeats and reading the average. It lights up and almost copies your heartrate. Not fully accurately but close enough to make the egg look alive.

Downloads

20241003_235955.mp4

Supplies

Electronic components

MAX30102 Oximeter Heart Rate Beat Pulse Sensor Module Arduino STM32 Project
Arduino Uno
Resistor 220 ohm
Red LED
Buzzer

Materials used for the housing

Terracotta clay to shape and to house the Arduino
Paper to add in some details
Black and white acrylic paints
White balloons to cover the plastic ball for a fleshy look
Hard plastic see-through ball that was used to hold awful old candy
Plastic little rocks for texturing

Tools used

My bare hands when dealing with terracotta
Soldering iron

Initial Ideas

The first initial idea (see the sketch above)

was to make it that you could wear scuba goggles while keeping your thumb on top of the heart rate sensor. If your heart rate was too high, it would start flashing lights within the goggles and blast annoying sounds into your ears. Bringing you into a stressful situation all around while you try to calm yourself down.

With this I wanted to give the experience of a panic attack underwater and needing to calm yourself down.

The second idea

was to make a opening and closing flower. This was inspired by one of my concept designs for Building playful worlds assignment. I created a underwater environment where this red coral blooms. With that in mind, I wanted to try recreating it. It opens up as the player walks closer. The more fear/the higher the heartrate the player has the more it opens up.

To create that I tried using a ball with a bunch of little "petals" on it. Pulling /pushing down on it makes it so that the petals open and close on each other. (see video)

This was later discontinued mainly due to the lack of time and resources but kept in mind for possible future fun silly projects.

Downloads

20240909_133538.mp4

Keeping It Simple But Not Stupid

Using the LED from initial idea 1 and the stationary object from idea 2; I combined what I had together and made the final concept.

The coral will now blink according to the heartbeat instead of opening and closing.

Code

#include <Wire.h>

#include "MAX30105.h"

#include "heartRate.h"

MAX30105 particleSensor;

const byte RATE_SIZE = 4; // Increase this for more averaging. 4 is good.

byte rates[RATE_SIZE]; // Array of heart rates

byte rateSpot = 0;

long lastBeat = 0; // Time at which the last beat occurred

int lightValue = 0;

float falloffDuration = 500;

long oldTime;

float beatsPerMinute;

int beatAvg;

// LED pin

const int ledPin = 9;

// Thresholds for heart rate

int lowThreshold = 60; // Example: Low heart rate threshold

int highThreshold = 100; // Example: High heart rate threshold

void setup() {

pinMode(ledPin, OUTPUT); // Set LED pin as output

Serial.begin(115200);

Serial.println("Initializing...");

// Initialize sensor

if (!particleSensor.begin(Wire, I2C_SPEED_FAST)) {

Serial.println("MAX30102 was not found. Please check wiring/power.");

while (1);

}

Serial.println("Place your index finger on the sensor with steady pressure.");

particleSensor.setup(); // Configure sensor with default settings

particleSensor.setPulseAmplitudeRed(0x0A); // Turn Red LED to low to indicate sensor is running

particleSensor.setPulseAmplitudeGreen(0); // Turn off Green LED

}

int EaseOut(int value, float delta)

{

float diff = pow(value / 255.0, 1.0 / 3.0);

diff = max(0, diff - delta / falloffDuration);

Serial.println(diff);

return diff * diff * diff * 255;

}

void loop() {

long irValue = particleSensor.getIR();

long currentTime = millis();

float delta = currentTime - oldTime;

oldTime = currentTime;

if (lightValue > 0)

{

lightValue = EaseOut(lightValue, delta);

analogWrite(ledPin, lightValue);

}

if (checkForBeat(irValue) == true) {

// We sensed a beat!

long beatDelta = currentTime - lastBeat; // Calculate time between beats

lastBeat = currentTime;

lightValue = 255;

analogWrite(ledPin, lightValue); // Half brightness for slow blinking

beatsPerMinute = 60 / (beatDelta / 1000.0); // Convert time between beats to bpm

if (beatsPerMinute < 255 && beatsPerMinute > 20) { // Remove anomalies from the average

rates[rateSpot++] = (byte)beatsPerMinute; // Store reading in array

rateSpot = rateSpot % RATE_SIZE; // Wrap variable

// Take average of readings

beatAvg = 0;

for (byte x = 0; x < RATE_SIZE; x++) {

beatAvg = beatAvg + rates[x];

}

beatAvg = beatAvg / RATE_SIZE;

}

Testing

Placement - Soldered - housed

Downloads

20241002_190335.mp4

20241003_125037.mp4

20241003_234316.mp4

... Was That Clay?

Yes that was clay! It looks scuffed but it did the job!

Given the little time I had along with personal things I had to deal with; I couldn't get my hands on a 3d printer to print my first initial housing for the Arduino. Most of them were already busy with projects or out of order.

So why not bring back the primal times of 3d modeling?

Polishing the scuffed looking clay

Applied some paint and silly little rocks for texturing to hide the ugly terracotta and actually make something more presentable.

Downloads

20241004_001022.mp4