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 
25 #include <iostream>
26 #include <string>
27 #include <stdexcept>
28 
29 #include "ta12200.h"
30 
31 using namespace upm;
32 using namespace std;
33 
TA12200(int pin)34 TA12200::TA12200(int pin)
35 {
36   initClock();
37 
38   if ( !(m_aio = mraa_aio_init(pin)) )
39     {
40       throw std::invalid_argument(std::string(__FUNCTION__) +
41                                   ": mraa_aio_init() failed, invalid pin?");
42       return;
43     }
44 }
45 
~TA12200()46 TA12200::~TA12200()
47 {
48   mraa_aio_close(m_aio);
49 }
50 
initClock()51 void TA12200::initClock()
52 {
53   gettimeofday(&m_startTime, NULL);
54 }
55 
getMillis()56 uint32_t TA12200::getMillis()
57 {
58   struct timeval elapsed, now;
59   uint32_t elapse;
60 
61   // get current time
62   gettimeofday(&now, NULL);
63 
64   // compute the delta since m_startTime
65   if( (elapsed.tv_usec = now.tv_usec - m_startTime.tv_usec) < 0 )
66     {
67       elapsed.tv_usec += 1000000;
68       elapsed.tv_sec = now.tv_sec - m_startTime.tv_sec - 1;
69     }
70   else
71     {
72       elapsed.tv_sec = now.tv_sec - m_startTime.tv_sec;
73     }
74 
75   elapse = (uint32_t)((elapsed.tv_sec * 1000) + (elapsed.tv_usec / 1000));
76 
77   // never return 0
78   if (elapse == 0)
79     elapse = 1;
80 
81   return elapse;
82 }
83 
84 
highestValue()85 unsigned int TA12200::highestValue()
86 {
87   unsigned int hiVal = 0;
88   unsigned int val;
89   uint32_t start = getMillis();
90 
91   // 1 second
92   while (getMillis() < (start + 1000))
93     {
94       val = mraa_aio_read(m_aio);
95       if (val > hiVal)
96         hiVal = val;
97     }
98 
99   return hiVal;
100 }
101 
milliAmps(unsigned int val,int res)102 float TA12200::milliAmps(unsigned int val, int res)
103 {
104   float ampCurrent;
105   float effectiveVal;
106 
107   // From grove wiki page:
108   // minimum_current=1/1024*5/800*2000000/1.414=8.6(mA)
109   // Only for sinusoidal alternating current
110   //ampCurrent = float(val) / float(res) * 5.0 / 800.0 * 2000000.0;
111   ampCurrent = float(val) / float(res) * 12500.0;
112   effectiveVal = ampCurrent/1.414;
113   return (effectiveVal);
114 }
115 
116