Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Yes i got it thank you , and sorry as well.
What is orp12[ not look like ldr in side view ] and is this necessary that led should be red with high intensity . now a days a white lde has more intensity .
Can I use it in as led source and simple ldr as rx sensor.
An ORP12 is the most common LDR there is. You use a high intensity red LED because you're trying to shine it through a finger - red should be far better than white for this!.
I tried building that circuit too, but had numerous problems with it.
I ended up deciding to design my own, I wanted to add the amount of oxygen in blood (SpO2) too. I havent done any formal electronic study for a number of years...so it is extremely difficult for me.
I have good pulse output using 3 stage transistor amp, that currently illuminates an led. The very difficult part is the SpO2 levels.
The pic will have no diffuculty in counting the number of pulses produced by the amplifier output.
I guess the point I'm trying to make is, if this is your in your final year (of course) and your playing with pics, then you should have the level of expertise to design your own.
I have designed my own and its been over 15 years since I did electronics at school.(GCSE) I have only been playing with pics for a couple of months, and have never had any formal training in pics. Granted I'm struggling with one aspect of my design but I'll get there eventually with some help from forums. I use the forums to check my ideas, and to seek help, advice.
I dont use it to rip off other peoples work.
At the end of the day I'm only a hobbyist.
I have to agree with andy257 ripping off someone elses work is a no no!!!!!!
Use other peoples work to discover the theory behind a project by all means, but to simply just copy for a qualification is very sad indeed.
I experimented with a white led, and sure enough I managed to get it to work.
However when compared to a high intensity (it must be a high intensity) red led. The red led is a lot easier, for mine I used a 3 stage transistor amp, when using the white led I needed 5 stages, and the signal was very, noisey.
I read another artical that used a high intensity blue led, which also worked.
My advice to you is to use the red led. Research photospectromitry, and it will explain (far better than I can) why the red light is better.
Just for information it is possible to use other colours too.!
Hi
Pehaps the red LED will not be able to pierce light thro' many fingures, depending on thckness , pigment color, roughness etc-- in a lighter corner -- like IanFlemming's GOLD FINGER-- the sensor may respond well for children and ladies and of those with tender fingers. the sensor may need a fresh outlook.
RN1 is eight 390 ohm resistors in one package and seven are used to limit the current from the PIC to (5V-1.8V)/390 ohms= 8.2mA for each segment of the display so the PIC doesn't overheat.
hi
we are also creating the heartbeat monitor for our semester project. we have come across a problem, that is we are unable to generate the hex file using MPLAB. it is reporting errors and since this is our semester project and we have not studied PIC programming yet, therefore we dont know what is going on. if somone has the hex file for the hemon.asm, can they plz give it to us?? or can anyone guide me to creating it successfully??
will be ever gratefull for ur help.
I think they went to university to learn how to read about sombody else's project and to solder.
They are probably using 741 opamps instead of the LM358 that works when its inputs are at ground.
The project shows the opamps' outputs:
1) The 1st opamp's output is a pulse up to about 3V during a heartbeat, the gain is set with the sensitivity pot.
2) The 2nd opamp's output is a square-wave up to about 3.7V during a heartbeat. It is a comparator.
In the interests of trying to help here, I suggest you take time to study the information in this link. It will teach you the methodology and demonstrate a system to measure heart rate etc. The use of an LDR for sensing is not the optimum method for life status monitoring systems....
when an led is connected at the output (pin 7) of the LM358, its flickring and not giving any discrete output.I tried varying the variable resistors but still the output was not discrete.Can someone help me why this problem is occuring.
Bloody hell is this for real?. A final year project is supposed to demonstrate your competence and skill as an engineer. If you copy someone elses project what does that show you have learned?
That's how they do it now day's all you need is a good computer fast net and ask on ever form then when it's broke they get real men an women to fix it.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
