How to connect a finger probe sensor (SPO2 sensor)to an arduino board?


I am trying to connect a finger probe sensor to the arduino uno r3 board. The sensor i am looking at and have researched for in the last couple of days is a nellcor ds-100 which has an RS 232 interface (DB9 connector). Now there are two problems i face.

(Problem 1) How can i connect it to the board?

Explanation: I came across
and this seems like a possible solution.

But do how do i connect the 6 pins to the board. According to my understanding VCC, GND and SIGNAL pin should be enough for a sensor to give the output.

(Problem 2) Am i supposed to process the output?

Explanation: Do i feed the output from the ttl module directly into my board or do some processing before that? I am thinking about feeding the output to a software oscilloscope like Xocillio <Link>

Please help (Alternate solutions would be appreciated too).


You need to find out how the sensor works.

These sort of devices were fashionable in laptop computers 6 years ago, they don't seem to be
so common now. There is quite a bit of processing involved in matching fingerprints. This
could be done inside the sensor, or more likely, the software to do it, is on the computer.

You need to search around, and see what you can find about the process, it may be difficult
as the makes of these gadgets would not be disseminating that information widely.

I have been researching on this and found out that most of the fingerprobe sensors have a RS232 DB9 male interface
and the best way to connect it to any device/ instrument is to buy an RS232-->X converter (X meaning TTL, USB or
whatever). In my case an RS232 DB9 - TTL converter (female) would suffice.

[Note: Guys be careful with what you buy. There are male/ female converters available. Most probably you would require a female