Of all the body responses one could monitor, heart rate is one of the most important because it fluctuates greatly depending on our state of mind and physical condition. Heart rate during physical activity gives us a direct indication of our fitness level, and heart rate changes throughout the night can be clear indicators of when a dream cycle has begun. A heart rate monitor is also a very easy device to use for extended periods because it can
be placed on the body in such a way that is not uncomfortable or in the way of any normal activity.

The heart rate monitor project presented here uses a sensitive light-detecting resistor to detect small changes in the light beaming through your finger as your blood pumps through the tiny arteries in the finger. This device is not the same as the heart rate monitors typically used in hospitals because those use skin probes that detect changes in electrical activity as the heart beats. This heart rate monitor actually “sees” your pulse through the body, so it can be used on a finger, toe, or even your earlobe.

The heart rate monitor is a combination of analog and digital circuitry, as shown below.



The LM324 quad op amp (IC1) forms a sensitive amplifier and a low-pass filter that will “lock” onto tiny variations in voltage that fall within the typical heart rate frequencies. The varying voltage comes from the light-dependent resistor (LDR), which changes a very small amount each time blood pumps through the tiny arteries in between the visible red LED and the LDR surface.




Complete Design



Insert Your Fingure Here







if you feel any doubt or need further details feel free to use Forum.
Source: Evil Genius MPP Issue 2010
[Submitted by coolmirza143]
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ExperimenterUK Avatar
Posted By ExperimenterUK
Tue Jul 29 2014, 02:08 PM
Remove all power connections to the circuit at the...
pravin_35 Avatar
Posted By pravin_35
Tue Jul 29 2014, 06:00 AM
Fyiimage with connections
pravin_35 Avatar
Posted By pravin_35
Tue Jul 29 2014, 05:53 AM
another chip is also same problem... i am confused...
pravin_35 Avatar
Posted By pravin_35
Tue Jul 29 2014, 01:41 AM
hi guys i found the following link is very useful...
ExperimenterUK Avatar
Posted By ExperimenterUK
Mon Jul 28 2014, 11:17 PM
Link the tx and rx pins on HC06, everything you se...
ExperimenterUK Avatar
Posted By ExperimenterUK
Mon Jul 28 2014, 11:13 PM
another chip is also same problem... i am confused...
pravin_35 Avatar
Posted By pravin_35
Mon Jul 28 2014, 01:33 PM
I suggest you to try with another chip of same and...
pravin_35 Avatar
Posted By pravin_35
Mon Jul 28 2014, 05:29 AM
I suggest you to try with another chip of same and...
ajay_bhargav Avatar
Posted By ajay_bhargav
Mon Jul 28 2014, 03:23 AM
I suggest you to try with another chip of same and...
pravin_35 Avatar
Posted By pravin_35
Mon Jul 28 2014, 03:11 AM
just now tried with Mplabx screen shotpravin_35Are...

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ajay_bhargav
Mon Jul 28 2014, 12:34 AM
@ Anshu Raj sorry we do not take such requests.
Sun Jul 27 2014, 12:23 AM
Anshu Raj
sir plz send the automatic collage alram bells in 2 hrs bells ring. For microcontroller programme plz sir
ajay_bhargav
Thu Jul 24 2014, 01:06 AM
@R.ABHISHEK where? I dont see it. is it in forum?
Wed Jul 23 2014, 05:49 AM
R.ABHISHEK
sir,pls message on microcontroller 8051 assambly language new program
Wed Jul 23 2014, 05:47 AM
R.ABHISHEK
sir,pls message on 8051 microcontroller assambly language program new quastions
ajay_bhargav
Tue Jul 22 2014, 09:18 AM
@Pragya Android application is taken from google play. Only Author has its source with him. Application is only used in this project.
Tue Jul 22 2014, 04:58 AM
Pragya
plz send me 8051 code and android code for android based device controller via Bluetooth .Here in this project I am using Hc-06 Bluetooth module
Thu Jul 10 2014, 09:57 AM
Caleb
plz someone mail me the source code for that project
Thu Jul 10 2014, 09:57 AM
Caleb
http://www.8051projects.net/download-d188-control-your-pc-tv-remote.html
ExperimenterUK
Tue Jul 08 2014, 03:25 PM
Post questions in the forum.. this area is for chat

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