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/*
* Author: Yevgeniy Kiveisha <yevgeniy.kiveisha@intel.com>
* Copyright (c) 2014 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 <iostream>
#include <unistd.h>
#include <stdlib.h>
#include <stdexcept>
#include "max31723.hpp"
using namespace upm;
MAX31723::MAX31723 (int csn) : m_csnPinCtx(csn), m_spi(0) {
mraa::Result error = mraa::SUCCESS;
m_name = "MAX31723";
error = m_csnPinCtx.dir (mraa::DIR_OUT);
if (error != mraa::SUCCESS) {
throw std::invalid_argument(std::string(__FUNCTION__) +
": m_csnPinCtx.dir() failed");
}
CSOff ();
// set spi mode to mode2 (CPOL = 1, CPHA = 0)
m_spi.mode (mraa::SPI_MODE2);
// set ontinuously perform temperature conversions
writeRegister (R_STS_WRITE_CMD, B_CONT_READING);
}
short
MAX31723::getTemperature () {
uint8_t lsb = 0;
uint8_t msb = 0;
short temperature = 0;
lsb = readRegister (R_TEMPERATURE_LSB);
msb = readRegister (R_TEMPERATURE_MSB);
if ((msb & 0x80) != 0) {
msb &= 0x7F;
temperature = 0 - msb;
} else {
temperature = msb;
}
return temperature;
}
/*
* **************
* private area
* **************
*/
uint8_t
MAX31723::readRegister (uint8_t reg) {
uint8_t data[2] = { 0x00, 0x00 };
uint8_t* sensorData = NULL;
CSOn ();
data[0] = reg;
sensorData = m_spi.write(data, 2);
CSOff ();
return sensorData[1];
}
void
MAX31723::writeRegister (uint8_t reg, uint8_t data) {
uint8_t buffer[2] = { 0x00, 0x00 };
uint8_t* sensorData = NULL;
CSOn ();
buffer[0] = reg;
buffer[1] = data;
sensorData = m_spi.write(buffer, 2);
CSOff ();
}
mraa::Result
MAX31723::CSOn () {
return m_csnPinCtx.write (HIGH);
}
mraa::Result
MAX31723::CSOff () {
return m_csnPinCtx.write (LOW);
}
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