I am using IR transmitting diode, a photodiode.
The signal conditioning circuit consists of 2 active low pass filters using opamp to boost the reflected light from the finger. The opamp I have used is MCP602 dual opamp for rail to rail output swing . And a 9V battery connected to lm7805 IC to derive a regulated 5v supply. The uC part has a 3digit common anode seven segment dislpay at the output of uC to display the heartrate. In the programme I have added a 15sec delay between each count of heartrate.
@UKHeliBob