68 lines
2.7 KiB
C
68 lines
2.7 KiB
C
/*
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Optical Heart Rate Detection (PBA Algorithm)
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By: Nathan Seidle
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SparkFun Electronics
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Date: October 2nd, 2016
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Given a series of IR samples from the MAX30105 we discern when a heart beat is occurring
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Let's have a brief chat about what this code does. We're going to try to detect
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heart-rate optically. This is tricky and prone to give false readings. We really don't
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want to get anyone hurt so use this code only as an example of how to process optical
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data. Build fun stuff with our MAX30105 breakout board but don't use it for actual
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medical diagnosis.
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Excellent background on optical heart rate detection:
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http://www.ti.com/lit/an/slaa655/slaa655.pdf
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Good reading:
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http://www.techforfuture.nl/fjc_documents/mitrabaratchi-measuringheartratewithopticalsensor.pdf
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https://fruct.org/publications/fruct13/files/Lau.pdf
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This is an implementation of Maxim's PBA (Penpheral Beat Amplitude) algorithm. It's been
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converted to work within the Arduino framework.
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*/
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/* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included
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* in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
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* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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* OTHER DEALINGS IN THE SOFTWARE.
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*
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* Except as contained in this notice, the name of Maxim Integrated
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* Products, Inc. shall not be used except as stated in the Maxim Integrated
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* Products, Inc. Branding Policy.
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*
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* The mere transfer of this software does not imply any licenses
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* of trade secrets, proprietary technology, copyrights, patents,
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* trademarks, maskwork rights, or any other form of intellectual
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* property whatsoever. Maxim Integrated Products, Inc. retains all
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* ownership rights.
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*
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*/
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#if (ARDUINO >= 100)
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#include "Arduino.h"
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#else
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#include "WProgram.h"
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#endif
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bool checkForBeat(int32_t sample);
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int16_t averageDCEstimator(int32_t *p, uint16_t x);
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int16_t lowPassFIRFilter(int16_t din);
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int32_t mul16(int16_t x, int16_t y);
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