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Step 2: Signal conditioning circuit

The reflected IR signal detected by the photo diode is fed to a signal conditioning circuit that filters the unwanted signals and boost the desired pulse signal. The circuit diagram above shows the IR LED (D1) and the photo diode (D2) along with the signal conditioning circuit made of two stage operational amplifiers configured as active low pass filters. The cut-off frequencies of both the filters are set to about 2.5 Hz, and so it can measure the pulse rate up to 2.5*60 = 150 bpm. The gain of each filter is about 100, which gives the total 2-stage amplification of 10000. This is good enough to convert the weak pulsating signal into a TTL pulse. Note that at the input of each OpAmp filter stage, there is a 1 uF capacitor to block any DC component in the signal. At the output is connected a LED that will blink with heart beat. The cathode of LED gets the ground path through the collector of BC547 transistor. In order to save the battery life, the transistor is turned on for 15 seconds by PIC16F628A microcontroller while the measurement is going on. The number of pulses counted within this interval is multiplied by 4 to get actual beats per minutes (bpm).  
Can you send mi the details of this project.. actually m doing d same n i want your project as a reference. . So please....?????<br>My mail is yogeshwarimane07@gmail.com <br>Thank you. .
<p>Done it, it was my first bigger project, and maybe too hard for beginner. But code is working only on PIC16F628A, but not on a PIC16F628</p>
Can u please sendme the details about this project to my mail ..... i am doing this as my main project so please send me....my mail is navyvijay187@gmail.com
Hello <br>If u really made it plZ snd me code and pcb layout....To my mail--- khushlingayat25@gmail.com
<p>sir,can u please send me this poject details to my mail id ishuuabi@gmail.com</p>
<p>could you please send me the programming commands of this project.</p><p>mail it to viddu_cm@yahoo.com</p>
<p>sir can you please send mi the source code and if possible please provide me entire details, mail id- chinmayshinde95.co.in@gmail.com</p>
<p>hello brother if u had really made it then plz mail me full details at .</p><p>vipulverma266@gmail.com</p>
<p>hello did you get the details on microcontroller measures heart rate through finger tip and if so can you please send me the details my email is imaniamani10@yahoo.com</p>
Nice
<p>Hi</p><p>Can you send me the code for the project. Thanks.</p>
<p>Hey i have a question have made the IR led at the sensor on/off(blinking) for few secs or just kept on ???</p>
<p>keep on, your blood pressure will &quot;imitate the blinking&quot;</p>
<p>what is the logic used to calculate heart rate ?</p>
<p>did u have the source code and the schematic??i want it please iqramkyoya@gmail.com</p>
<p>yes, but everything is in subscription</p>
<p>hello sir ! do u have any kind of project details? can u send to me</p><p>bungatulip6617@rocketmail.com</p><p>tq sir..</p>
<p>good day sir, can you please send me the pcb layout that you made im kind of new to this project. please help me.</p><p>email add: derek.gabs@gmail.com</p>
<p>hello sir, i am going to do this project for my final year project submission. can you please mail me the details and source code for this project? it will help me a lot.</p><p>my mail id mitraniloy@gmail.com.</p><p>thanks in advance.</p>
<p>Good Day Sir!</p><p>Can you give me the pcb layout of your project.??? :)</p><p>And the simulation of this project if you don't mind.</p><p>Hope to reply as soon as possible.</p><p>Thank You so MUCH.</p><p>GODBLESS. </p><p>This is my e-mail address. </p><p>skyweak0024@gmail.com</p>
<p>Good Day Sir!</p><p>Can you give me the pcb layout of your project.??? :)</p><p>And the simulation of this project if you don't mind.</p><p>Hope to reply as soon as possible.</p><p>Thank You so MUCH.</p><p>GODBLESS. </p><p>This is my e-mail address. </p><p>skyweak0024@gmail.com</p>
<p>my dear .. plz connect this project but it not work &gt;&gt; i was using pic16f628a </p><p>but it not work !!</p><p>plz send me the source code and all names of all components and explain to me how you connect the circuit on akrm33766@yahoo.com </p><p>or on facebook https://www.facebook.com/akram44444</p>
<p>Hi, Can you please send me the project with all details and source code. </p><p>My e-mail is : diana20120101@gmail.com</p>
<p>Can you please send me full details about this project, the component needed, the code source. I really need it , and thank you in advance to this email: kadi0dal@gmail.com</p>
<p>I'm doing project in this domain..so please send me the pdf regarding this project to the following mail id navyvijay187@gmail.com..</p>
<p>can you please send me the source code and if possible please provide me entire details, and hookup? email: mateo.smetko1802@gmail.com</p>
<p>Dear sir<br></p><p>please send me the project detiles to my email id</p><p>aditya.avadhani.mattur@gmail.com</p><p>mobile number : 9483560138<br></p><p>Sir<br> I am intrested in the project of ROBOTICS and BIOMEDICAL INSTRUMENT <br>please send me any project on the above topic to my email .</p><p>Thank you</p>
<p>Hi Sir,</p><p>How do upload program to micro controller pic16f628a...please reply me </p><p>suganyaravi67@gmail.com</p>
<p>what software did you use to program the pic16f628a?</p>
<p>Please send me the project requirement....</p>
<p>hey plz send more report abt this project .......</p>
<p>Is it possible that we can add in the program that it can measure heart rate without resetting? I mean, it can measure continuously and update the display every time it measures. </p>
<p>Your reply would mean so much to me since I'll be doing this as a final project. Thanks in advance. if you want to email me, lovelypacz@gmail.com . </p>
<p>hey</p><p>plz send d complete report of dis project..with d source code as m in urgent need of a project</p><p>email id-kavya1495@gmail.com</p>
<p>hey</p><p>plz send d complete report of dis project..with d source code as m in urgent need of a project</p><p>email id-kavya1495@gmail.com</p>
<p>hii can u send me the code for this project</p><p>my email is : bargav234@gmail.com</p>
<p>hii can u send me the code for this project</p><p>my email is : bargav234@gmail.com</p>
<p>Hi</p><p>Can you send me the code for the project???</p><p>Hope to reply as soon as possible.</p><p>Thank You so much.</p><p>my email is : m.hasanlu93@yahoo.com</p>
<p>can u send me all files if u recived it ?</p>
<p>mostafagad9090@gmail.com</p>
<p>please can u send me the design of the circut and PCB and hex file !<br>my email : mostafagad9090@gmail.com</p>
<p>please can u sen me component list used in this project at </p><p>revanthrampal@gmail.com </p>
<p>sir, this project is really impressive, i will be very glad if you could just send me the simulation and pcb layout for this project so that i can further try to implement it.</p><p>splendid.ayushi @gmail.com</p>
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Wtf
Dear sir,<br>My heartbeat sensor which i have made using ldr and led,detect the movement of finger but not blood flow.<br>So please help me.<br>By: shailesh<br>Email: shuklask8@gmail.com
My heart beat sensor which is made by led and ldr ,detect movement of finger but not blood flow.so please help me.<br>From:shailesh<br>Email:shuklask8@gmail.com

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