spo2 with red led n ir led.

Thread Starter


Joined Nov 6, 2011
need some help in doin a project in spo2..idea is to determine the oxygen content in blood using ir led and red led..like there is a difference in absorption of red n ir in deoxy n oxy haemoglobin.. i did many circuits found in net but nothin came to use ..need the circuit and code if possible. thz


Joined Apr 5, 2008

I found this post in the "completed projects" forum.
As it says it is for completeled projects.

Now I moved it here and made it visible to the others.

Please can you explain more what you are trying to do in normal english in stead of sms lanquage.


Thread Starter


Joined Nov 6, 2011
i want to do a project in spo2..the main idea is to measure the amount of oxygen present in blood.. idea i got till now is that,blood contain two sections ,the oxy haemoglobin and the deoxy haemoglobin.ok
ir led and red led is driven in a frequency that only one is on at a time..as i said early the oxy haemoglobin absorbs more ir and the normal red. also the deoxy haemoglobin absords more red light than ir..so there will be a difference in absorption ..
i did some circuits found in net..but i couldnt go forward with that..
thz :D


Joined Feb 19, 2009
Are you aware there is a Shift key on your keyboard?

The nearest translation I can come up with is you are attempting to make a Blood Oxygen Meter aka \(SpO_2\) meter.

You were instructed that this was possible with an IR LED and a Red LED. What are you using for a receiver?

Please post schematic(s) of what you have so far, and use spell check, and if able, use closer to correct English spelling, punctuation, and grammar.

<grumpy old man shakes head at "kids these days">

Thread Starter


Joined Nov 6, 2011
thzz 4 reply .. its ok wt my grammer n spellings.. i use language to convey my thots and don want to get away prizes in any contest..k..moderator can remove me frm ds site..bye..ppl luk into knowledge f a person nt d grammer n punctuations


Joined Nov 25, 2009
Grammar and syntax are the rules of proper use of the medium called language. If you use the medium correctly, you will get appropriate results faster and people will be willing to share a conversation with you.
Here in AAC we are lenient and understanding when the language barrier is concerned, but if you can use the medium correctly, you have no reason not to.

Try to compare it with driving a car backwards to get to your destination.


Joined Jul 17, 2007
I can only speak for myself.

When I view an inquiry for help that needlessly has such poor grammar and spelling, I usually won't bother to post a reply.

If the original poster won't make the effort to at least be mostly correct in their spelling/grammar and have shown to have put forth some effort in researching their project, then why should I expend the effort to do so for them?

There are many members who do not write/speak English as their native language; however many of them are better writers than those who are native English speakers/writers. I tend to make much more of an effort to help those people solve their dilemmas, as they are obviously making more of an effort to communicate in my native language, and doing a very good job of it.