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Topic: How to connect a finger probe sensor (SPO2 sensor)to an arduino board? (Read 7872 times) previous topic - next topic



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 http://www.beepbee.com/rs232-serial-port-to-ttl-converter-communication-module-for-arduino-p-32150.html#.UUIVZzeyLbd
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 http://code.google.com/p/xoscillo/>

Please help (Alternate solutions would be appreciated too).


For question 1: just use the Rx and Tx pins, they are the UART pins. It's all serial, so use Serial.print or read for communication. You have to set the baudrate to a known speed, e.g 9600.

BUT: are you sure it's serial communication? I think they just use the DB9 connector because it has 9 pins, not for serial communication.
See: http://pinouts.ru/forum/index.php?topic=4679.0


I can concur with kong. While the ds-100 has a 9 pin connector it is not a serial connection just connections to the photodiodes and LEDs.


Don't PM me for help as I will ignore it.


i am doing the same thing with a nellcore and a db9 it is not serial at all there are actually 4 pins that you need and the two led are charliplexed but i am still working on how to get readings
pins if the top was the one with 5 pins
pin 2 and 3 are the leds to be charliplexed
pin 5 is the  photo resistor
pin 9 goes to ground
and it read is varying amps so you nee to convert that for the arduino


Hi guys,

Did any one solve this problem of connecting Spo2 to arduino. Iam not able to find a solution to this problem of connecting D9 pin to arduino board. Any help on this is greatly appreciated.


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