In this guide, we’ll walk you through the process of interfacing a heartbeat sensor with an Arduino to monitor a person’s live heartbeat. Additionally, we’ll demonstrate how to connect an OLED display to the Arduino to visualize real-time data.

Components Needed:

• Arduino Uno
• Heartbeat Sensor
• OLED Display
• Jumper Wires

Heartbeat Sensor Pinout:

The heartbeat sensor features three pins: VCC, GND, and Analog Output.

• VCC: Power supply pin of the sensor module.
• GND: Ground pin of the sensor module.
• Signal: Analog Output Signal Pin of the sensor module.

Functioning of Heartbeat Sensor:

The heartbeat sensor operates by detecting subtle changes in blood flow through the skin caused by the expansion and contraction of blood vessels with each heartbeat. It typically utilizes an optical or electrical method to capture these changes.

In our optical sensor, an LED emits light that penetrates the skin and blood vessels, while a photodetector measures the amount of light absorbed or reflected back. As blood vessels expand and contract, the amount of light absorbed or reflected changes, enabling the sensor to calculate the heart rate. This method is known as Photoplethysmogram.

Components of a Heartbeat Sensor:

At the front of the heartbeat sensor, there are the photodiode and IR LEDs to detect the heartbeat. At the back, an op-amp provides gain to the circuit, and a reverse voltage protection diode safeguards against ESD and reverse voltage. Additional capacitors and resistors act as RC filters to reduce external noise.

Frequently Asked Questions about Heartbeat Sensor Modules:

1. Are heartbeat sensor modules safe to use?
   Yes, heartbeat sensor modules emit low levels of non-harmful light, making them safe for use, similar to pulse oximeters and medical devices.
2. Can heartbeat sensor modules be used for medical purposes?
   While they provide heart rate data, they may not meet medical-grade accuracy and regulatory requirements. They are commonly used for fitness and wellness applications.
3. Do heartbeat sensor modules work for people of all ages and skin tones?
   They can work for people of different ages and skin tones, but variations may affect measurement ease. Some sensors may be better suited for specific skin types or conditions.

Pulse Sensor Module Circuit Diagram:

The circuit diagram includes essential components such as a filter capacitor, Green LED, resistor, diode for power distribution, an operational amplifier, and a photodiode sensor IC. RC low-pass filters clean the signal, while the op-amp amplifies it for microcontroller processing.

Arduino Heartbeat Sensor Interface Circuit Diagram:

Connect the VCC and GND pins of the heartbeat sensor to the 5V and GND pins on the Arduino, respectively. Then, connect the Analog OUT pin of the heartbeat sensor to an analog input pin on the Arduino, such as A0.