MAX31855.c

/*
 * MAX31855.c
 *
 *  Created on: 16.08.2021
 *      Author: SimpleMethod
 *
 *Copyright 2021 SimpleMethod
 *
 *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 "MAX31855.h"


void MAX31855_Init(MAX31855_StateHandle *MAX31855, SPI_HandleTypeDef * hspi,GPIO_TypeDef *GPIOx, uint16_t GPIO_Pin)
{
	 MAX31855->hspi=hspi;
	 MAX31855->nss.pin=GPIO_Pin;
	 MAX31855->nss.port=GPIOx;
	 MAX31855_SetNSSState(MAX31855,GPIO_PIN_SET);
}
uint8_t MAX31855_GetFault(MAX31855_StateHandle *MAX31855)
{
	if(MAX31855->ocFault)
	{
		return 1;
	}
	else if(MAX31855->scgFault)
	{
		return 2;
	}
	else if(MAX31855->scvFault)
	{
		return 3;
	}
	else
	{
		return 0;
	}

}
float MAX31855_GetTemperature(MAX31855_StateHandle *MAX31855)
{
	 return MAX31855->extTemp*0.25;
}
float MAX31855_GeInternalTemperature(MAX31855_StateHandle *MAX31855){
	 return MAX31855->intTemp*0.0625;
}

float MAX31855_GetTemperatureInFahrenheit(MAX31855_StateHandle *MAX31855)
{
 	 float temp=MAX31855_GetTemperature(MAX31855);
 	 temp*=1.8;
 	 temp += 32;
 	 return temp;
}
float MAX31855_GeInternalTemperatureInFahrenheit(MAX31855_StateHandle *MAX31855){
	 float temp=MAX31855_GeInternalTemperature(MAX31855);
	 temp*=1.8;
	 temp += 32;
	 return temp;
}

void MAX31855_ReadData(MAX31855_StateHandle *MAX31855)
{
	uint8_t payload[4];
	int32_t frame;
	MAX31855_SetNSSState(MAX31855,GPIO_PIN_RESET);
	HAL_SPI_Receive(MAX31855->hspi, payload, 4, 1000);
	MAX31855_SetNSSState(MAX31855,GPIO_PIN_SET);
	MAX31855->scvFault=0;
	MAX31855->scgFault=0;
	MAX31855->ocFault=0;
	MAX31855->fault=0;
	MAX31855->extTemp=0;
	MAX31855->extTempSign=0;
	MAX31855->intTemp=0;
	MAX31855->intTempSign=0;

	frame = payload[0];
	frame = frame<<8;
	frame = frame|payload[1];
	frame = frame<<8;
	frame = frame|payload[2];
	frame = frame<<8;
	frame = frame|payload[3];
	int32_t extTemp=frame;
	int32_t intTemp=frame;

	if(frame& 0b00000000000000000000000000000100)
	{
		MAX31855->scvFault=1;
	}
	if(frame& 0b00000000000000000000000000000010)
	{
		MAX31855->scgFault=1;
	}
	if(frame& 0b00000000000000000000000000000001)
	{
		MAX31855->ocFault=1;
	}
	if(frame&0b00000000000000010000000000000000)
	{
		MAX31855->fault=1;
	}
	if(frame&0b10000000000000000000000000000000)
	{
		MAX31855->extTempSign=1;
	}
	if(frame&0b00000000000000010000000000000000)
	{
		MAX31855->intTempSign=1;
	}

	extTemp>>=18;
	if (MAX31855->intTempSign) {
		extTemp = ~(extTemp & 0b11111111111111);
	}
	MAX31855->extTemp=extTemp;

	intTemp = ((intTemp>>4) & 0b11111111111);
	if (MAX31855->intTempSign)
	{
		intTemp=~(intTemp|0b1111100000000000); //Experimental code, not tested!
	}
	MAX31855->intTemp=intTemp;
}


void MAX31855_SetNSSState(MAX31855_StateHandle *MAX31855, GPIO_PinState state)
{
	HAL_GPIO_WritePin(MAX31855->nss.port,MAX31855->nss.pin,state);
}