1 /*
2  * Author: Brendan Le Foll <brendan.le.foll@intel.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 #pragma once
26 
27 #include <stdexcept>
28 #include "aio.h"
29 #include "types.hpp"
30 
31 namespace mraa
32 {
33 
34 /**
35  * @brief API to Analog IO
36  *
37  * This file defines the aio interface for libmraa
38  *
39  * @snippet AioA0.cpp Interesting
40  */
41 class Aio
42 {
43   public:
44     /**
45      * Aio Constructor, takes a pin number which will map directly to the
46      * board number
47      *
48      * @param pin channel number to read ADC inputs
49      */
Aio(unsigned int pin)50     Aio(unsigned int pin)
51     {
52         m_aio = mraa_aio_init(pin);
53         if (m_aio == NULL) {
54             throw std::invalid_argument("Invalid AIO pin specified - do you have an ADC?");
55         }
56     }
57     /**
58      * Aio destructor
59      */
~Aio()60     ~Aio()
61     {
62         mraa_aio_close(m_aio);
63     }
64     /**
65      * Read a value from the AIO pin. By default mraa will shift
66      * the raw value up or down to a 10 bit value.
67      *
68      * @returns The current input voltage. By default, a 10bit value
69      */
70     int
read()71     read()
72     {
73         return mraa_aio_read(m_aio);
74     }
75     /**
76      * Read a value from the AIO pin and return it as a normalized float.
77      *
78      * @returns The current input voltage as a normalized float (0.0f-1.0f)
79      */
80     float
readFloat()81     readFloat()
82     {
83         return mraa_aio_read_float(m_aio);
84     }
85     /**
86      * Set the bit value which mraa will shift the raw reading
87      * from the ADC to. I.e. 10bits
88      * @param bits the bits the return from read should be i.e 10
89      * @return mraa::Result type
90      */
91     Result
setBit(int bits)92     setBit(int bits)
93     {
94         return (Result) mraa_aio_set_bit(m_aio, bits);
95     }
96     /**
97      * Gets the bit value mraa is shifting the analog read to.
98      *
99      * @return bit value mraa is set return from the read function
100      */
101     int
getBit()102     getBit()
103     {
104         return mraa_aio_get_bit(m_aio);
105     }
106 
107   private:
108     mraa_aio_context m_aio;
109 };
110 }
111