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 #include <iostream>
26 #include <string>
27 #include <stdexcept>
28 #include <unistd.h>
29 #include <stdlib.h>
30 #include <functional>
31 #include <string.h>
32 #include "mic.h"
33
34 using namespace upm;
35
Microphone(int micPin)36 Microphone::Microphone(int micPin) {
37 // initialise analog mic input
38
39 if ( !(m_micCtx = mraa_aio_init(micPin)) )
40 {
41 throw std::invalid_argument(std::string(__FUNCTION__) +
42 ": mraa_aio_init() failed, invalid pin?");
43 return;
44 }
45 }
46
~Microphone()47 Microphone::~Microphone() {
48 // close analog input
49 mraa_result_t error;
50 error = mraa_aio_close(m_micCtx);
51 if (error != MRAA_SUCCESS) {
52 mraa_result_print(error);
53 }
54 }
55
56 int
getSampledWindow(unsigned int freqMS,int numberOfSamples,uint16_t * buffer)57 Microphone::getSampledWindow (unsigned int freqMS, int numberOfSamples,
58 uint16_t * buffer) {
59 int sampleIdx = 0;
60
61 // must have freq
62 if (!freqMS) {
63 return 0;
64 }
65
66 // too much samples
67 if (numberOfSamples > 0xFFFFFF) {
68 return 0;
69 }
70
71 while (sampleIdx < numberOfSamples) {
72 buffer[sampleIdx++] = mraa_aio_read (m_micCtx);
73 usleep(freqMS * 1000);
74 }
75
76 return sampleIdx;
77 }
78
79 int
findThreshold(thresholdContext * ctx,unsigned int threshold,uint16_t * buffer,int len)80 Microphone::findThreshold (thresholdContext* ctx, unsigned int threshold,
81 uint16_t * buffer, int len) {
82 long sum = 0;
83 for (unsigned int i = 0; i < len; i++) {
84 sum += buffer[i];
85 }
86
87 ctx->averageReading = sum / len;
88 ctx->runningAverage = (((ctx->averagedOver-1) * ctx->runningAverage) + ctx->averageReading) / ctx->averagedOver;
89
90 if (ctx->runningAverage > threshold) {
91 return ctx->runningAverage;
92 } else {
93 return 0;
94 }
95 }
96
97 void
printGraph(thresholdContext * ctx)98 Microphone::printGraph (thresholdContext* ctx) {
99 for (int i = 0; i < ctx->runningAverage; i++)
100 std::cout << ".";
101 std::cout << std::endl;
102 }
103