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

Other Hardware Home Automation
1

Hi,

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 Google Code Archive - Long-term storage for Google Code Project Hosting.>

Please help (Alternate solutions would be appreciated too).

Priyankar

2

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: Nellcor DS-100A sensor for pulse oximeter

3

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.

4

This might be helpfull.

5

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

6

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.

Thanks

7

Have a look at TIDM-EKG-PULSE reference design | TI.com it uses the probe sensor in question. Definitely not serial.
Also the following link has a picture of the pinout. Ремонт датчиков сатурации кислорода (SpO2 sensors)