IoT用クラウドサービス「Ambient」と心拍センサーを使った心拍モニターです。心拍センサー「Pulse Sensor Amped」の値をmbed「Simple IoT Board」で読み、「Ambient」に送信してモニターします。 https://ambidata.io
Dependencies: AmbientLib SimpleIoTBoardLib mbed
pulseSensor.cpp
- Committer:
- AmbientData
- Date:
- 2016-06-13
- Revision:
- 4:ec1aa2beefce
- Parent:
- 1:0053efdb355e
File content as of revision 4:ec1aa2beefce:
/* * The MIT License (MIT) * * Copyright (c) 2015 Pulse Sensor * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include "mbed.h" AnalogIn pulsePin(dp13); DigitalOut led(dp6); #define SAMPLING 2000.0f // Sampling period in micro seconds 2msec volatile int rate[10]; // array to hold last ten IBI values volatile unsigned long sampleCounter = 0; // used to determine pulse timing volatile unsigned long lastBeatTime = 0; // used to find IBI volatile int P =512; // used to find peak in pulse wave, seeded volatile int T = 512; // used to find trough in pulse wave, seeded volatile int thresh = 525; // used to find instant moment of heart beat, seeded volatile int amp = 100; // used to hold amplitude of pulse waveform, seeded volatile bool firstBeat = true; // used to seed rate array so we startup with reasonable BPM volatile bool secondBeat = false; // used to seed rate array so we startup with reasonable BPM // Volatile Variables, used in the interrupt service routine! volatile int BPM; // int that holds raw Analog in 0. updated every 2mS volatile int Signal; // holds the incoming raw data volatile int IBI = 600; // int that holds the time interval between beats! Must be seeded! volatile bool Pulse = false; // "True" when User's live heartbeat is detected. "False" when not a "live beat". volatile bool QS = false; // becomes true when Arduoino finds a beat. Ticker t2; // THIS IS THE TICKER INTERRUPT SERVICE ROUTINE. // Ticker makes sure that we take a reading every 2 miliseconds void sampling() { // triggered every 2 miliseconds Signal = (int)(pulsePin.read()*1023); // read the Pulse Sensor sampleCounter += 2; // keep track of the time in mS with this variable int N = sampleCounter - lastBeatTime; // monitor the time since the last beat to avoid noise // find the peak and trough of the pulse wave if(Signal < thresh && N > (IBI/5)*3){ // avoid dichrotic noise by waiting 3/5 of last IBI if (Signal < T){ // T is the trough T = Signal; // keep track of lowest point in pulse wave } } if(Signal > thresh && Signal > P){ // thresh condition helps avoid noise P = Signal; // P is the peak } // keep track of highest point in pulse wave // NOW IT'S TIME TO LOOK FOR THE HEART BEAT // signal surges up in value every time there is a pulse if (N > 250){ // avoid high frequency noise if ( (Signal > thresh) && (Pulse == false) && (N > (IBI/5)*3) ){ Pulse = true; // set the Pulse flag when we think there is a pulse IBI = sampleCounter - lastBeatTime; // measure time between beats in mS lastBeatTime = sampleCounter; // keep track of time for next pulse if(secondBeat){ // if this is the second beat, if secondBeat == TRUE secondBeat = false; // clear secondBeat flag for(int i=0; i<=9; i++){ // seed the running total to get a realisitic BPM at startup rate[i] = IBI; } } if(firstBeat){ // if it's the first time we found a beat, if firstBeat == TRUE firstBeat = false; // clear firstBeat flag secondBeat = true; // set the second beat flag return; // IBI value is unreliable so discard it } // keep a running total of the last 10 IBI values unsigned runningTotal = 0; // clear the runningTotal variable for(int i=0; i<=8; i++){ // shift data in the rate array rate[i] = rate[i+1]; // and drop the oldest IBI value runningTotal += rate[i]; // add up the 9 oldest IBI values } rate[9] = IBI; // add the latest IBI to the rate array runningTotal += rate[9]; // add the latest IBI to runningTotal runningTotal /= 10; // average the last 10 IBI values BPM = 60000/runningTotal; // how many beats can fit into a minute? that's BPM! QS = true; // set Quantified Self flag // QS FLAG IS NOT CLEARED INSIDE THIS ISR led = 1; } } if (Signal < thresh && Pulse == true){ // when the values are going down, the beat is over Pulse = false; // reset the Pulse flag so we can do it again amp = P - T; // get amplitude of the pulse wave thresh = amp/2 + T; // set thresh at 50% of the amplitude P = thresh; // reset these for next time T = thresh; led = 0; } if (N > 2500){ // if 2.5 seconds go by without a beat thresh = 512; // set thresh default P = 512; // set P default T = 512; // set T default lastBeatTime = sampleCounter; // bring the lastBeatTime up to date firstBeat = true; // set these to avoid noise secondBeat = false; // when we get the heartbeat back } } void interruptSetup(){ // Initializes Ticker to throw an interrupt every 2mS. t2.attach_us(&sampling, SAMPLING); }