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Heart Beat Monitor with Infra-red AND LDR Sensor

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schematic bpw34

for pulseoximetry can nhave a look to :

reference design from TI

For photodiode frontend - transimpedance amplifier is what actually needed and widely used for photodiode interfacing.
There (ebook subforum) should be book on this subject . Also this paper could be interresting as well :
**broken link removed**
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led used as photodiode


this is another nice artical which is free about the uses and application of photo diode some kind of math given to used with uC



how does a photodiode go bad

Hello guys my name is nik and i am interested in the heart rate monitor. I cant download however the files that you have uploaded at the forum as i dont have enough points.

I will read what the procedure is to get some points.



pic with photodiode

To detect heartbeat similar to the way the basic pulse oximter does, I've been using TCRT1010. Although not to be used for actual medical diagnosis, it's definitely good enough for me to record my own heartbeat and fun with it. It has a compact construction where the emitting-light source and the detector (phototransisitor) are arranged in the same direction. Its worth looking into.

heart beat sensor details using ldr

racheps_1986 said:
hi i am Newbie. I am doing a project in it. But I am not able to download the above given file as I dont have enough points.
Please Fragrance can u mail it to the following email ID-racheps_1986(at)

Pravin said:
hi i am currently working on this project of the pulse oximeter. i have all the required products for the project meaning the ir, red led and the photodiode. but i am not sure of how to assemble it and how to write a programme for this can anyone please help me on this aspect. thank you

to both of you 2o point donated racheps and for pravin you need a programmer to program the provided hex file into microcontroller sensor you can made in two way used cloth clip or pvc pipe


photodiode an pic

Hi, I am dian
i am interested with pulse oximeter
but I cann't download your file
Please Fragrance, could you donate your point to me
Thank you very much for your help
my email is

details in working of photodiode

can u explain the circuit for the HEMON. how does it amplify and filter the circuit ? the hand analysis calculation for the circuit, the gain and such? and at the pulse waveform at pin 7 i still get a digital signal only not the analog signal, why is that?. and do you think i could change the sensor with honeywell sensor 1395-001 to go with the circuit?

heartbeat monitor project/banglore

Hi there,

looking for some info on photodiodes and barcode scanning


why ldr is used in heart bit sensor?

hey, what these point thing all about?:|


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principle of bpw34

hai, i am working on the project heart beat monitor..can u guys please send the details of it

schemtaic bpw34

could anyone please share that file with me too cause i, too dont have enough points to download the file :( please?

thank you very much.


working projects on photodiode

haha ,I realy don't know how much of my point

photodiode interrupter circuits

I am doing a project in it. But I am not able to download the above given file as I dont have enough points.

projects based on photodiod

Thank you for this project. It's very interresting and I want to test it this week.

For moment I only have one question:

Why it talks about 1 photo interrupter for IRLED1 (Jaycar Cat. Z-1901 or equivalent) in the document and we saw a single IRLED picture on the schematic? Which IRLED we must take?

Thank you

Fragrance said:

here is the final version of last uploaded file which has lot new feature all infomation pcb pic code for programing sensor making info and construstion guide here is some main feature

Main Features
1 Ideal for use with exercise machines
2 Adjustable timer with buzzer
3 Visible pulse indicator
4 Timer end buzzer
5 Timer stops below minimum pulse beat rate
6 Start/stop timer control
7 Recovery display 1,2,3,4 & 5 minutes
8 Error display for no pulse
9 Minimum & maximum pulse settings for audible buzzer

puls oxi photo diode

hello everybody
i need help to build a simple pulse oximeter circuit
if anybody can send me this electronic circuit with all component, so i'll be gratfull of him.
moreover, i need help in a new configuration to change the RED and IR LEDs with a laser diodes within range of the same wavelength of RED and IR.
if someone knows, please help me.
it is a task of me in my studies, must finish it during this month
thanks for all,,,

i think am quiet late to the forum :S. any ways its better late then never.
well , my problem is that i am working on a biomedical project whose part is to monitor heart rate. i tried to use an IR led and a photo diode, but wus unsuccessful.i dnt know where the problem is , so am searching for different articles. there was an attachment by sir Fragrance, which am unable to download. can any body help me with it ??

Added after 19 minutes:

sum how, am able to download it now.. and have started to work on it.


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can i make a heart rate sensor with the help of a micro phone insted of using optical thing??
would it be simpler ??

P.s reply ASAP.

Re: photodiode frontend

Alvin81 said:
Hi Fragrance,

I've tried using the circuit diagram b4 this....I've even sampled the output of the circuit using PIC's input capture and displaying it graphically on the PC using VB. However, I've noticed each time the sensor is used, it gives out different reading of the heart beat period. Anyone knows why this is so?


hi can u send me on more details on how u connect it via VB ?? i need ur help , thanks

thank for this information ,i have to build heart beat monitor and oxygen rate but instead of used complete electronics have to use Labview when use filters and to see the plus if anybody could help me i will really appreciate that
best regards

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