/* * Author: Jon Trulson * Copyright (c) 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 "teams.hpp" using namespace upm; using namespace std; // for current loop reads that seems a little noisy, we average over // several aio reads. static const int maxSamples = 50; // conversion from celsius to fahrenheit static float c2f(float c) { return (c * (9.0 / 5.0) + 32.0); } TEAMS::TEAMS(int tPin, float rResistor, float aref) : m_aioTemp(tPin) { if (rResistor < 0.0) { throw std::out_of_range(std::string(__FUNCTION__) + ": rResistor must be >= 0.0"); } m_aResTemp = (1 << m_aioTemp.getBit()); m_temperature = 0.0; m_aref = aref; m_rResistor = rResistor; m_connected = false; // this will only be non-zero when using a direct 4-20ma interface // like libelium m_rawMilliamps = 0.0; m_offset = 0.0; } TEAMS::~TEAMS() { } void TEAMS::update() { float milliamps = 0.0; int val = average(maxSamples); float volts = (float(val) * (m_aref / m_aResTemp)); // valid temp range is 25.0 (35C - 10C), current loop range is 16ma // (20ma - 4ma) if (m_rResistor) { // direct 4-20 current loop interface milliamps = (volts / m_rResistor * 1000.0) + m_offset; m_rawMilliamps = milliamps; // subtract 0 (4ma) value milliamps -= 4.0; if (milliamps < 0.0) // not connected { milliamps = 0.0; m_connected = false; } else m_connected = true; m_temperature = (milliamps * (25.0 / 16.0)) + 10.0; } else { // normal analog read, already scaled to 0-5v, always connected m_temperature = ((volts / m_aref) * 25.0) + 10.0; m_connected = true; } } float TEAMS::getTemperature(bool fahrenheit) { if (fahrenheit) return c2f(m_temperature); else return m_temperature; } int TEAMS::average(int samples) { if (samples <= 0) samples = 1; int avg = 0; for (int i=0; i