Heartbeat sensor is used to detect heartbeats. It can be wore on the finger or earlobe and connected to Arduino via cables. It also carries an open source program to display heart rate via diagrams in real time. It is an optical heart rate sensor integrated with amplifying circuit and noise cancellation circuit.
The principle behind the working of the Heartbeat Sensor is Photoplethysmograph. According to this principle, the changes in the volume of blood in an organ is measured by the changes in the intensity of the light passing through that organ.
The source of light in a heartbeat sensor is an IR LED and the detector is a Photo Detector. With these two i.e. a light source and a detector, we can arrange them in two ways: A Transmissive Sensor and a Reflective Sensor.
In a Transmissive Sensor, the light source and the detector are place facing each other and the finger of the person must be placed in between the transmitter and receiver.
Reflective Sensor, on the other hand, has the light source and the detector adjacent to each other and the finger of the person must be placed in front of the sensor.