TCRT1000 – Reflective Optical Sensor
Manufactured by Vishay Semiconductors
I ordered it from Mouser
For more information visit: Sensor Report – Reflective Optical Sensor TCRT1000
Although, I am not convinced about the code they are using or the schematic… my schematic is working . This is probably NOT the most reliable pulse reader, but since I am not looking for high-fidelity in my project, this will do just fine.
For a more accurate DIY HRV sensor, check out Collin’s Lab Infrared Heart Sensor