Arduino Based Heartbeat Monitor

Published  October 7, 2015   111
S Saddam
Heartbeat Monitor Project using Arduino

Heart rate, body temperature and blood pressure monitoring are very important parameters of human body. Doctors use various kind of medical apparatus like thermometer for checking fever or body temperature, BP monitor for blood pressure measurement and heart rate monitor for heart rate measurement. In this project, we have built an Arduino based heartbeat monitor which counts the number of heartbeats in a minute. Here we have used a heartbeat sensor module which senses the heartbeat upon putting a finger on the sensor.



  1. Arduino
  2. Heart Beat sensor module
  3. 16x2 LCD
  4. Push button
  5. Bread board
  6. Power
  7. Connecting wires


Working of Heartbeat Monitor Project

Working of this project is quite easy but a little calculation for calculating heart rate is required. There are several methods for calculating heart rate, but here we have read only five pulses. Then we have calculated total heart beat in a minute by applying the below formula:


      Single_pulse_time= Five_pusle_time /5;

      rate=60000/ Single_pulse_time;

where time1 is first pulse counter value

time2 is list pulse counter value

rate is final heart rate.


When first pulse comes, we start counter by using timer counter function in arduino that is millis();. And take first pulse counter value form millis();. Then we wait for five pulses. After getting five pulses we again take counter value in time2 and then we substarct time1 from time2 to take original time taken by five pulses. And then divide this time by 5 times for getting single pulse time. Now we have time for single pulse and we can easily find the pulse in one minute, deviding 600000 ms by single pulse time.

Rate= 600000/single pulse time.

Arduino Based Heartbeat Monitor Block Diagram

In this project we have used Heart beat sensor module to detect Heart Beat. This sensor module contains an IR pair which actually detect heart beat from blood. Heart pumps the blood in body which is called heart beat, when it happens the blood concentration in body changes. And we use this change to make a voltage or pulse electrically.


Circuit Diagram and Explanation

Circuit of heartbeat monitor is shown below, which contains arduino uno, heart beat sensor module, reset button and LCD. Arduino controls whole the process of system like reading pulses form Heart beat sensor module, calculating heart rate and sending this data to LCD. We can set the sensitivity of this sensor module by inbuilt potentiometer placed on this module. 

Arduino Based Heartbeat Counter Circuit Diagram

Heart beat sensor module’s output pin is directly connected to pin 8 of arduino. Vcc and GND are connected to Vcc and GND. A 16x2 LCD is connected with arduino in 4-bit mode. Control pin RS, RW and En are directly connected to arduino pin 12, GND and 11. And data pin D4-D7 is connected to pins 5, 4, 3 and 2 of arduino. And one push button is added for resetting reading and another is used to start the system for reading pulses. When we need to count heart rate, we press start button then arduino start counting pulses and also start counter for five seconds. This start push button is connected to pin 7 and reset push button is connected to pin 6 of arduino with respect to ground.


Program Description

In code we have used digital read function to read output of Heart Beat sensor module and millis() fuction for calculating time and then calculate Heart Rate.

heartbeat counter code

Before this we have initiazed all the components that we used in this project.


and here we have pullup the push button line by using software pullup.




LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

int in = 8;
int Reset=6;
int start=7;
int count=0,i=0,k=0,rate=0;

unsigned long time2,time1;
unsigned long time;

byte heart[8] = 

void setup()
  lcd.createChar(1, heart);
  lcd.print("Heart Beat ");
  pinMode(in, INPUT);
  pinMode(Reset, INPUT);
  pinMode(start, INPUT);
  digitalWrite(Reset, HIGH);
  digitalWrite(start, HIGH);

void loop()
    lcd.print("Please wait.......");
      lcd.print("Heart Beat Rate:");
      lcd.print(" ");
      lcd.print("Heart Beat Rate:");


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Submitted by Mary ann on Thu, 12/17/2015 - 18:30


can I have the full code please...

Submitted by Nge on Wed, 01/06/2016 - 11:25


what is the parts no of the Heart Beat sensor module ? Cuz I want to buy.

Submitted by Avinash on Fri, 02/19/2016 - 18:30


Can i know exactly which sensor module is used in this project ??
Can i have the details about the sensor module

Submitted by Mathan Raj Murugan on Mon, 03/07/2016 - 11:19


Hi Abhishek,
do you have any sample code for testing heart beat sensor ij arduino which you used in this project. i am having same sensor i ported everything i had troubleshoot it.but i cant read the value.i want to check the sensor value via serial monitor.whether this sensor read the value or not.could you please share the code for testing heart beat sensor.

Submitted by Mathan Raj Murugan on Tue, 03/15/2016 - 11:56


I did everything same..but I didn't get proper pulse..getting value is over exceeding .like most of the time I am getting above 100 there any mistake from me?could you please give me the soultion for me?

Submitted by Shankar Kumar Pandit on Fri, 03/25/2016 - 14:37


i have connected all the wires and its showing the reading but not accurate reading sometimes its show 340 sometimes 1000 and even sometimes -1 so its not accurate even i adjust the pot of sensor

Submitted by Le Toan on Sun, 04/10/2016 - 10:57


how do not need to press the button after 5 seconds, press once every ro run forever?

Submitted by haura on Tue, 05/10/2016 - 23:17


Thanks a lot, this project well helpful in my final year project...

Submitted by ROOPA on Wed, 05/11/2016 - 20:15



Submitted by Handy I. R. Mosey on Thu, 05/26/2016 - 18:09


hi. .
Its a fabulous work of you.
My question is how can we develop this system to monitor (say 5 family members at the same time) heart beat in real time using a web server or with an android device. Well, that just an idea. Please excuse my poor english.
Handy Mosey

Submitted by Manikandan.T on Sat, 07/02/2016 - 12:43


can you explain the code fully ...step by step each lines please!!!!!!!
i cannot understand the code.and the main thing is the calculation part can not understand because i m the beginning.

Submitted by G S Kelkar on Tue, 07/05/2016 - 18:26


Can you supply the code for monitoring the pulse continuously? i.e. each pulse is to be taken into consideration and obtain the time bet next pulse and display the rate. Also time in milli seconds can be exported along with pulse rate. This will be very good gazed for measuring HRV. Thanks and awaiting your reply

Submitted by shilpa.r on Mon, 08/08/2016 - 21:11


hi, i have connected all the wires but i am not getting the correct output, i am getting some random values as output,and i am not using lcd i am checking the output in aurdino serial monitor. should i change anything in code????

Submitted by Bienvenido on Wed, 08/17/2016 - 23:10


can you suggest different model of 16 x 2 lcd display other than LM016L? Because i'm using a different model of lcd display and it does not display any results. thank you.

Submitted by Adhithya raj on Fri, 08/19/2016 - 15:16


Hi, i have connected all the wires but i am not getting the correct output, i am getting some random values as output,and i am not using lcd i am checking the output in aurdino serial monitor. What should i change in code????can u please give me the code part without LCD interface....

Submitted by RAMESH on Fri, 08/19/2016 - 22:51


i used heart monitor sensor n not gettingcorrect pulses,i think it is analog output,not working with this,pl conferm what type sensor to be use.

Submitted by Eric on Sun, 08/28/2016 - 20:12


Why my project cannot display the heart rate although i get the program and circuit correctly?

Submitted by bala on Thu, 09/01/2016 - 17:17


i connected everything correctly even though i am not getting the out put correctly. can you please give me the code for arduino serial port.instead of photo diode i am using photo transistor am not getting the correct output.

Submitted by Nim on Sun, 09/04/2016 - 10:52


The arduino doesn't calculate the heart hate thr is any problems in code

Submitted by swathi Reddy on Tue, 09/13/2016 - 18:04


I am using KY-039 Heartbeat sensor and I have connected all the connections properly.

But it is displaying heartbeat rate : -1.

Are their any mistakes in code if so mail me the code please.

Do we need to connect S pin of sensor to 8 pin of arduino and middlepin of sensor to VCC of arduino?

I am not able to understand how to use heartbeat sensor.
At what angle IR LED should be placed?
Someone reply quickly.

Submitted by R.Aswathy Rajan on Thu, 09/15/2016 - 00:12


When was the last research done in this project?

Submitted by Steven Cory Weiser on Thu, 10/27/2016 - 06:11


Hello fellow Ardweeners..I have completed this project and can offer anyone help if needed..One of the problems that I had was getting the sensors to read an actual heartbeat. It is very tricky and difficult to get your finger in the perfect position that the sensors can patient yet determined you will get it. Use a cell phone camera to make sure the infrared led is emitting, you will see a purple-ish glow, through the camera but not with just your eyes..Once I connected the arduino and started to read the heartbeats I noticed i would always get a number at least 2 times the actual number, ie.. instead of a b.p.of 55 the lcd screen would read 110.I found out that the arduino was counting the small signal at the beginning of the heartbeat as a heartbeat itself, so I simply changed the formula for rate by dividing it by see on an oscilliscope the heart beat actually appears as 2 pulses in 1 where the beginning of the beat there is a small pulse ,I supposes one of the heart ventricles open followed by a bigger more significant pulse the actual heartbeat.Although not necessary I also added a amplifier to the circuit to increase the gain of the heartbeat, also added a red led as an extra light source for the infrared phototransistor as in actual oximeters there are 2 lights sources both visible and infrared
my email is beatlessteve at gmail dot com..good luck yall!..

Submitted by babes on Tue, 11/08/2016 - 17:08


I am currently doing design project,so my chosen project is heartbeat and temperature monitor.I would like to use arduino for this project but I am not familiar with it .I would like you to pls explain a bit to me about it

Submitted by Muhammad Umer on Wed, 11/09/2016 - 09:50


Hi Sir !
Do i really need the switches ?
or can i just make one switch of reset ?
and explain if it is possible?

Submitted by Muhammad Mohsin on Tue, 12/20/2016 - 20:11


bro i am using KY 039 but the problem is it takes too much time at "please wait" and sometimes gives the reading but usually a false one like 25 or 30, any tip for troubleshooting??

Submitted by Mark on Mon, 01/02/2017 - 20:15


It's a very simple and useful monitor. I just have one question about the code:
>>>> while(digitalRead(in));
What does this while do? I didn't get it because the pin will be reading zero every time you take a signal from the sensor, so would it get a 1 (HIGH) to continue the loop?

Thanks in advance.

Submitted by muhammad furqan on Fri, 01/13/2017 - 18:55


hy can any one please tell . i got problem when i presss the button lcd shows "please wait" and remains there and does not show any value

Submitted by Prajakta Mahadik on Tue, 02/07/2017 - 22:12


I m not using Display. And i want to print actual data ie actual heart rate of the human body. so how can i achieve this? For actual data representation what is hanges in this program.

Submitted by thanusree .k on Thu, 03/09/2017 - 21:10


How can i send the message ( heart rate ) to a doctor or a hospital unit using GSM in interafacing with the arduino...plz send me the circuit & code..if you know

Submitted by saikumar.k on Mon, 03/27/2017 - 14:14


i got one problem ,when i placed any object like pen on hear beat sensor it dispalys value. pls give solution to this problem

Submitted by karamjeet on Fri, 04/07/2017 - 23:34


i have connected it but it is always showing please wait message .Can anyone help to sort out this problem

Submitted by Shubham on Fri, 04/14/2017 - 23:19


Please help I can't see the full code of this project. Because of overlap in starting codes please full code. From starting.

Submitted by GAYATHRI on Thu, 04/20/2017 - 22:10


1.can we detect whether a person is prone to heartattack by measuring few samples from time to time?
2.if there is a sudden change in heartbeat....can we generate a warning?

Submitted by BHAVANA S on Mon, 05/08/2017 - 15:07


Hii Sir,
We are using Heartbeat sensor in our project. We done with same type of connection what you given above. I am getting d output, but it is showing 200, 500,600 sometimes -10. I tried many times. But not getting d exact output. Sir please help me. Because we need to submit our project by Wednesday. Please give me solution within Tuesday .