/* * Authors: Brendan Le Foll * Mihai Tudor Panu * Sarah Knepper * Copyright (c) 2014 - 2016 Intel Corporation. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include #include #include #include "grovetemp.hpp" #include "math.h" using namespace upm; GroveTemp::GroveTemp(unsigned int pin, float scale, int r0, int b) { if ( !(m_aio = mraa_aio_init(pin)) ) { throw std::invalid_argument(std::string(__FUNCTION__) + ": mraa_aio_init() failed, invalid pin?"); return; } m_name = "Temperature Sensor"; m_scale = scale; m_r0 = r0; m_b = b; } GroveTemp::~GroveTemp() { mraa_aio_close(m_aio); } int GroveTemp::value () { float a = (float) mraa_aio_read(m_aio); if (a == -1.0) return -1; // Apply scale factor after error check a *= m_scale; float r = (float)(1023.0-a)*(float)m_r0/a; float t = 1.0/(log(r/(float)m_r0)/(float)m_b + 1.0/298.15)-273.15; return (int) round(t); } float GroveTemp::raw_value() { return (float) mraa_aio_read(m_aio); }