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/*
* Author: Marc Graham <marc@m2ag.net>
* Copyright (c) 2015 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 "mcp9808.hpp"
#include <cmath>
using namespace upm;
MCP9808::MCP9808 (int bus, uint8_t address){
m_name = "mcp9808";
m_celsius = true;
m_tcrit = false;
m_tupper = false;
m_tlower = false;
if(!(i2c = new mraa::I2c(bus))){
throw std::invalid_argument(std::string(__FUNCTION__) +": I2c.init() failed");
return;
}
if((i2c->address(address) != mraa::SUCCESS)){
throw std::invalid_argument(std::string(__FUNCTION__) + ": I2c.address() failed");
return;
}
if(i2c->frequency( mraa::I2C_FAST) != mraa::SUCCESS){
throw std::invalid_argument(std::string(__FUNCTION__) + ": I2c.frequency(I2C_STD) failed");
return;
}
}
float
MCP9808::getTemp(){
uint16_t result;
//Read the register
result = i2c->readWordReg(MCP9808_REG_AMBIENT_TEMP);
//Swap the bytes
result = swapWord(result);
//Get the flag bits.
m_tcrit = (result & 0x8000) ;
m_tupper = (result & 0x4000) ;
m_tlower = (result & 0x2000) ;
return getTempValue(result);
}
void
MCP9808::shutDown(bool sleep){
if(sleep) this->updateConfigRegister(MCP9808_CONFIG_SHUTDOWN);
else this->updateConfigRegister(~(MCP9808_CONFIG_SHUTDOWN), false);
}
void
MCP9808::setMonitorReg(MCP9808_REG reg, float value){
uint16_t t;
if(m_celsius) t = value * 16.0;
else t = ((value - 32) * 5.0/9.0) * 16.0 ;
t = swapWord(t);
if(i2c->writeWordReg(reg, t) != mraa::SUCCESS){
throw std::invalid_argument(std::string(__FUNCTION__) + ": I2c.write() failed");
return;
}
}
float
MCP9808::getMonitorReg(MCP9808_REG reg){
uint16_t value = i2c->readWordReg(reg);
value = swapWord(value);
return getTempValue(value);
}
void
MCP9808::clearInterrupt(){
this->updateConfigRegister(MCP9808_CONFIG_INTCLR);
}
void
MCP9808::setAlertMode(uint16_t command){
this->updateConfigRegister(command);
}
void
MCP9808::clearAlertMode(){
//Preserve hysteresis and shutdown settings but
//set all alert settings to power on default.
this->updateConfigRegister(0x2007, false);
}
void
MCP9808::setHysteresis(MCP9808_CONFIG value){
//Clear hysteresis first.
this->updateConfigRegister(0xFFF9, false);
this->updateConfigRegister(value);
}
float
MCP9808::getHysteresis(){
uint16_t value = i2c->readWordReg(MCP9808_REG_CONFIG);
value = (value >> 1 ) & 0xF ;
float res = (value == 0) ? 0.0 : ( 1.5 * pow( 2.0 , value - 1 )) ;
return (m_celsius) ? res : res * 9/5;
}
void
MCP9808::setResolution(MCP9808_RESOLUTION value){
if(i2c->writeReg(MCP9808_REG_RESOLUTION, value) != mraa::SUCCESS){
throw std::invalid_argument(std::string(__FUNCTION__) + ": I2c.write() failed");
return;
}
}
float
MCP9808::getResolution(){
uint8_t value = i2c->readReg(MCP9808_REG_RESOLUTION);
return 0.5 * (1.0 / std::pow( 2.0, value));
}
uint16_t
MCP9808::getManufacturer(){
return swapWord(i2c->readWordReg(MCP9808_REG_MANUF_ID));
}
uint16_t
MCP9808::getDevicedId(){
return swapWord(i2c->readWordReg(MCP9808_REG_DEVICE_ID));
}
MCP9808::~MCP9808 (){
delete i2c;
}
//Private functions
float
MCP9808::getTempValue(uint16_t result){
bool neg = (result & 0x1000);
float res = (result & 0xFFF) / 16.0;
if(neg) res = 0 - ( 256 - res );
if(!m_celsius) res = res * 9.0/5.0 + 32;
return res;
}
void
MCP9808::updateConfigRegister(uint16_t update, bool on){
uint16_t reg = i2c->readWordReg(MCP9808_REG_CONFIG);
if(on) reg |= update;
else reg &= update;
if(i2c->writeWordReg(MCP9808_REG_CONFIG, reg) != mraa::SUCCESS){
throw std::invalid_argument(std::string(__FUNCTION__) + ": I2c.write() failed");
return;
}
}
uint16_t
MCP9808::swapWord(uint16_t value){
uint16_t res = value;
return ((res & 0xFF) << 8) | ((res >> 8 ) & 0xFF);
}
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