Heart Rate Sensor

Page last updated 22 Oct 2015, by Jonathan Owens. 1 reply

Introduction

This device measures the heart rate optically and outputs the BPM of the user onto the screen.

/media/uploads/Jonathan/heart_rate_monitor.png

Materials Used

  • Photo Resistor from SparkFun
  • 330 Resistor
  • 10k Resistor
  • uLCD-144 board
  • Red LED
  • Wires
  • BreadBoard

How It Works

The red LED and the photo resistor should be beside each other when wiring up the circuit (look at pictures for reference). By placing the thumb over the Photo Resistor, the overall resistance of the photoresistor will change. When the blood is pumped through the thumb, It will cause less light to reflect onto the photoresistor. This causes a voltage fluctuation which can be interpreted into BPM by the MBED.

Breadboard

/media/uploads/Jonathan/heart_sensor_updated.png

Schematic

/media/uploads/Jonathan/schematic_updated.png

Videos Demo

Code

Import programHeartRateMonitor

Optical heart rate monitor using photoresistor and LED to calculate BPM, which is outputted to LCD screen.

Last commit 28 Oct 2015 by Mary-Ann Ionascu

1 comment on Heart Rate Sensor:

Bethany Harrison
27 Nov 2018

Do you have a schematic of the breadboard without the labels on it? They are in the way of some wires, so I don't know how to properly assemble the circuit.

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