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//###########################################################################
//
// FILE: F2837xD_TempSensorConv.c
//
// TITLE: F2837xD Temperature Sensor Conversion Functions
//
//###########################################################################
// $TI Release: F2837xD Support Library v3.05.00.00 $
// $Release Date: Tue Jun 26 03:15:23 CDT 2018 $
// $Copyright:
// Copyright (C) 2013-2018 Texas Instruments Incorporated - http://www.ti.com/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the
// distribution.
//
// Neither the name of Texas Instruments Incorporated nor the names of
// its contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// $
//###########################################################################
//
// Included Files
//
#include "F2837xD_device.h"
#include "F2837xD_Examples.h"
//
// Defines
//
#define FP_SCALE 32768 //Scale factor for Q15 fixed point numbers (2^15)
#define FP_ROUND FP_SCALE/2 //Added to Q15 numbers before converting to
//integer to round the number.
#define KELVIN 273 // Amount to add to Q15 fixed point numbers
// to shift from Celsius to Kelvin
// (Converting guarantees number is
// positive, which makes rounding more
// efficient)
#define KELVIN_OFF FP_SCALE*KELVIN
#define getTempSlope() (*(int (*)(void))0x7036E)() //Slope of temperature sensor
//(deg. C / ADC code).
//Stored in fixed point Q15
//format.
#define getTempOffset() (*(int (*)(void))0x70372)() //ADC code corresponding to
//temperature sensor output
//at 0 deg. C
//
// Globals
//
float32 tempSensor_tempSlope;
float32 tempSensor_tempOffset;
float32 tempSensor_scaleFactor;
//
// InitTempSensor - Initialize the temperature sensor by powering up the
// sensor, loading the calibration values from OTP to RAM,
// and recording the intended VREFHI voltage.
// Note: This function doesn't support VREFLO != 0.0V,
// but this could be implemented if desired.
//
void InitTempSensor(float32 vrefhi_voltage)
{
EALLOW;
//
//power up the the temperature sensor
//
AnalogSubsysRegs.TSNSCTL.bit.ENABLE = 1;
//
//delay to allow the sensor to power up
//
DELAY_US(1000);
EDIS;
//
//need to remember VREFHI voltage so that sensor readings can be scaled
//to match 2.5V values used for calibration data.
//
tempSensor_scaleFactor = vrefhi_voltage;
//
//check the device revision
//
if(DevCfgRegs.REVID >= 3)
{
//
//for production devices (Rev. C), pull the slope and offset from OTP
//
tempSensor_tempSlope = (int32)getTempSlope();
tempSensor_tempOffset = getTempOffset();
}
else
{
//
//for pre-production devices, use these static values for slope
//and offset
//
tempSensor_tempSlope = 5196;
tempSensor_tempOffset = 1788;
}
}
//
// GetTemperatureC - This function uses the reference data stored in OTP to
// convert the raw temperature sensor reading into degrees C
//
int16 GetTemperatureC(int16 sensorSample)
{
sensorSample = (int16)((tempSensor_scaleFactor/2.5)*(sensorSample));
return (((sensorSample - tempSensor_tempOffset)*tempSensor_tempSlope +
FP_ROUND + KELVIN_OFF)/FP_SCALE - KELVIN);
}
//
// GetTemperatureK - This function uses the reference data stored in OTP to
// convert the raw temperature sensor reading into degrees K
//
int16 GetTemperatureK(int16 sensorSample)
{
sensorSample = (int16)((2.5/tempSensor_scaleFactor)*(sensorSample));
return (((sensorSample - tempSensor_tempOffset)*tempSensor_tempSlope +
FP_ROUND + KELVIN_OFF)/FP_SCALE);
}
//
// End of file
//
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