1 /*
2 * Author: Jon Trulson <jtrulson@ics.com>
3 * Copyright (c) 2015 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 "rotaryencoder.h"
30
31 using namespace upm;
32 using namespace std;
33
RotaryEncoder(int pinA,int pinB)34 RotaryEncoder::RotaryEncoder(int pinA, int pinB)
35 {
36 if ( !(m_gpioA = mraa_gpio_init(pinA)) )
37 {
38 throw std::invalid_argument(std::string(__FUNCTION__) +
39 ": mraa_gpio_init(pinA) failed, invalid pin?");
40 return;
41 }
42
43 mraa_gpio_dir(m_gpioA, MRAA_GPIO_IN);
44
45 if ( !(m_gpioB = mraa_gpio_init(pinB)) )
46 {
47 throw std::invalid_argument(std::string(__FUNCTION__) +
48 ": mraa_gpio_init(pinB) failed, invalid pin?");
49 return;
50 }
51
52 mraa_gpio_dir(m_gpioB, MRAA_GPIO_IN);
53
54 m_position = 0;
55
56 // setup the ISR
57
58 // We would prefer to use MRAA_GPIO_EDGE_BOTH for better resolution,
59 // but that does not appear to be supported
60 mraa_gpio_isr(m_gpioA, MRAA_GPIO_EDGE_RISING,
61 &signalAISR, this);
62 }
63
~RotaryEncoder()64 RotaryEncoder::~RotaryEncoder()
65 {
66 mraa_gpio_isr_exit(m_gpioA);
67
68 mraa_gpio_close(m_gpioA);
69 mraa_gpio_close(m_gpioB);
70 }
71
initPosition(int count)72 void RotaryEncoder::initPosition(int count)
73 {
74 m_position = count;
75 }
76
position()77 int RotaryEncoder::position()
78 {
79 return m_position;
80 }
81
signalAISR(void * ctx)82 void RotaryEncoder::signalAISR(void *ctx)
83 {
84 upm::RotaryEncoder *This = (upm::RotaryEncoder *)ctx;
85
86 if (mraa_gpio_read(This->m_gpioA))
87 {
88 if (mraa_gpio_read(This->m_gpioB))
89 This->m_position++; // CW
90 else
91 This->m_position--; // CCW
92 }
93 }
94
95
96