1 /* 2 * Author: Jon Trulson <jtrulson (at) 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 "maxsonarez.h" 30 31 using namespace std; 32 using namespace upm; 33 34 MAXSONAREZ::MAXSONAREZ(int pin, float aref) 35 { 36 if (!(m_aio = mraa_aio_init(pin))) 37 { 38 throw std::invalid_argument(std::string(__FUNCTION__) + 39 ": mraa_aio_init() failed, invalid pin?"); 40 return; 41 } 42 43 m_aRes = (1 << mraa_aio_get_bit(m_aio)); 44 m_aref = aref; 45 46 // volt's per inch of this sensor 47 m_vI = (m_aref / MAXSONAREZ_RES); 48 } 49 50 MAXSONAREZ::~MAXSONAREZ() 51 { 52 mraa_aio_close(m_aio); 53 } 54 55 int MAXSONAREZ::inches() 56 { 57 int val = mraa_aio_read(m_aio); 58 float volts = float(val) * (m_aref / m_aRes); 59 60 return int(volts / m_vI); 61 } 62