For my final project, I made a light that beats with my pulse. I call it diamond heart.
Link to my instructable: https://www.instructables.com/Diamond-Heart/
Material list:
- 3d printing filament PLA red transparent
- A white T-shirt
- pulse sensor
- a long USB-c cord
- Arduino nano board
Diagram sketch:

On NANO:

Worked:

Coding:
// Pin Definitions
const int heartbeatPin = 2; // Pin connected to heartbeat sensor signal
const int ledPin = 3; // Pin connected to LED
void setup() {
pinMode(heartbeatPin, INPUT); // Set heartbeat pin as input
pinMode(ledPin, OUTPUT); // Set LED pin as output
}
void loop() {
// Read the heartbeat sensor’s signal
int heartbeat = digitalRead(heartbeatPin);
if (heartbeat == HIGH) { // Heartbeat detected
digitalWrite(ledPin, HIGH); // Turn on the LED
} else {
digitalWrite(ledPin, LOW); // Turn off the LED
}
}
Verified & uploaded:

How it works on my pulse:

Put battery+Nano board in the diamond heart case:


3d printed them:

Final :

If I would do it again, I will:
- Set up 3d printing slicing data differently so the surface can be probably smoother/or thinking about more materials.
- Think about the target group and audience/ using scenarios.
- Probably have more LED so it can be brighter.