1 /*
2  * Author: Jon Trulson <jtrulson@ics.com>
3  * Copyright (c) 2014 Intel Corporation.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining
6  * a copy of this software and associated documentation files (the
7  * "Software"), to deal in the Software without restriction, including
8  * without limitation the rights to use, copy, modify, merge, publish,
9  * distribute, sublicense, and/or sell copies of the Software, and to
10  * permit persons to whom the Software is furnished to do so, subject to
11  * the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be
14  * included in all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23  */
24 #pragma once
25 
26 #include <string>
27 #include <stdint.h>
28 #include <sys/time.h>
29 #include <mraa/gpio.h>
30 
31 namespace upm {
32   /**
33    * @brief Grove Ear-clip Heart Rate Sensor library
34    * @defgroup groveehr libupm-groveehr
35    * @ingroup seeed gpio medical
36    */
37 
38   /**
39    * @library groveehr
40    * @sensor groveehr
41    * @comname Grove Ear-clip Heart Rate Sensor
42    * @type medical
43    * @man seeed
44    * @con gpio
45    *
46    * @brief API for the Grove Ear-clip Heart Rate Sensor
47    *
48    * UPM module for the Grove ear-clip heart rate sensor. It is used to measure your
49    * heart rate.
50    *
51    * @image html groveehr.jpg
52    * @snippet groveehr.cxx Interesting
53    */
54   class GroveEHR {
55   public:
56     /**
57      * GroveEHR constructor
58      *
59      * @param pin Digital pin to use
60      */
61     GroveEHR(int pin);
62     /**
63      * GroveEHR destructor
64      */
65     ~GroveEHR();
66     /**
67      * Returns the time of milliseconds elapsed since initClock()
68      * was last called.
69      *
70      * @return Elapsed milliseconds
71      */
72     uint32_t getMillis();
73 
74     /**
75      * Resets the clock
76      *
77      */
78     void initClock();
79 
80     /**
81      * Resets the beat counter to 0. The beat counter should be
82      * stopped via stopBeatCounter() prior to calling this function.
83      *
84      */
85     void clearBeatCounter();
86 
87     /**
88      * Starts the beat counter
89      *
90      */
91     void startBeatCounter();
92 
93     /**
94      * Stops the beat counter
95      *
96      */
97     void stopBeatCounter();
98 
99     /**
100      * Gets the beat Counter
101      *
102      * @return Beat counter
103      */
104     uint32_t beatCounter();
105 
106     /**
107      * Computes the heart rate
108      *
109      * @return Computed heart rate
110      */
111     int heartRate();
112 
113   private:
114     /**
115      * Beat interrupt service routine (ISR)
116      *
117      */
118     static void beatISR(void *ctx);
119 
120     volatile uint32_t m_beatCounter;
121     struct timeval m_startTime;
122     mraa_gpio_context m_gpio;
123   };
124 }
125 
126 
127