SparkFun Pulse Oximeter and Heart Rate Monitor Hookup Guide

Contributors: Elias The Sparkiest
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Reference Tables and Sensor Settings

This section shows some of the sensor's settings in clear tables so that you don't have to run to the datasheet for reference. It will also help to expand upon some unique characteristics of the SparkFun Bio Sensor Hub Library. Feel free to move beyond this section and jump to the Example Section below until this information becomes relevant in one of the examples.

BioData Information

As you'll see below, the library uses a type that is unique to the SparkFun Pulse Oximeter and Heart Rate Monitor. The name of this type is bioData and with it we'll be able to get at the biometric data that comes out of the board. Below is a table that shows all of the possible data stored within this mysterious new container, it has been named body for the table below and the following examples.

bioData Members Information Provided
body.heartrate Heart rate
body.oxygen Blood Oxygen Levels
body.confidence The Sensor's confidence in the reported data.
body.status Finger Detection
body.irLed Number of IR LED Samples
body.redLED Number of Red LED Samples

BioData Mode 2

In addition to the information above, mode 2 also gives the following two data points.

bioData Members Information Provided
body.rValue Sp02 r Value
body.extStatus Extended Finger Status Message

Finger Status

Below is a reference table for the body.status member which tells you if the sensor has detected a finger or some other object that is not a finger. It relays this information with four numbers: 0-3.

Status Number Description
0 No Object Detected
1 Object Detected
2 Object Other Than Finger Detected
3 Finger Detected

Below is a reference table for the body.exStatus member which is an expansion of the first finger status messaging. This is enabled in mode 2 and contains 8 different values.

Status Number Description
0 Success
1 Not Ready
-1 Object Detected
-2 Excessive Sensor Device Motion
-3 No object detected
-4 Pressing too hard
-5 Object other than finger detected
-6 Excessive finger motion

Pulse Width vs. Sample Collection

There is trade off between higher resolution (i.e. longer pulse width) and the number of samples that you can collect per second. The table below shows how the resolution and sample rate interact.

Samples/Second Pulse Width (uS)
69 118 215 411
50 O O O O
100 O O O O
200 O O O O
400 O O O O
800 O O O
1000 O O
1600 O
Resolution (bits) 15 16 17 18