This file is part of OneWire routines

by Isaac Marino Bavaresco

/*============================================================================*/
/*
 Copyright (c) 2016-2019, Isaac Marino Bavaresco
 All rights reserved.
 isaacbavaresco@yahoo.com.br

 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.
     * Neither the name of the author 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 AUTHOR ''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 AUTHOR 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.
*/
/*============================================================================*/
#include <string.h>
#include "OneWire.h"
#include "DS18B20.h"
/*============================================================================*/
onewirestatus_t DS18B20ReadTemperature( const ibuttonsn_t *SerialNumber, short *Temperature )
    {
    unsigned char   CRC8, Buffer[DS18B20_SCRATCHPAD_SIZE];
    onewireint_t    i;
    onewirestatus_t Status;
    int             Result;

    if(( Status = OneWireReset() ) != ONE_WIRE_STATUS_OK )
        return Status;

    if( SerialNumber == NULL )
        {
        if(( Status = OneWireWriteByte( ONE_WIRE_COMMAND_SKIP_ROM )) != ONE_WIRE_STATUS_OK )
            return Status;
        }
    else
        {
        if(( Status = OneWireMatchROM( SerialNumber )) != ONE_WIRE_STATUS_OK )
            return Status;
        }

    if(( Status = OneWireWriteByte( DS18B20_COMMAND_READ_SCRATCHPAD )) != ONE_WIRE_STATUS_OK )
        return Status;

    for( CRC8 = 0, i = 0; i < DS18B20_SCRATCHPAD_SIZE; i++ )
        {
        if(( Result = OneWireReadByte() ) < ONE_WIRE_STATUS_OK )
            return (onewirestatus_t)Result;
        CRC8    = CalcCRC8( CRC8, Buffer[i] = (unsigned char)Result );
        }
    if(( Result = OneWireReadByte() ) < ONE_WIRE_STATUS_OK )
        return (onewirestatus_t)Result;
    if( CRC8 != (unsigned char)Result )
        return ONE_WIRE_STATUS_CRC_ERROR;

    *Temperature    = (int)(( (unsigned int)Buffer[1] << 8 ) | ( (unsigned int)Buffer[0] << 0 ));
    return ONE_WIRE_STATUS_OK;
    }
/*============================================================================*/
onewirestatus_t DS18B20StartConversion( const ibuttonsn_t *SerialNumber )
    {
    onewirestatus_t Status;

    if(( Status = OneWireReset() ) != ONE_WIRE_STATUS_OK )
        return Status;

    if( SerialNumber == NULL )
        {
        if(( Status = OneWireWriteByte( ONE_WIRE_COMMAND_SKIP_ROM )) != ONE_WIRE_STATUS_OK )
            return Status;
        }
    else
        {
        if(( Status = OneWireMatchROM( SerialNumber )) != ONE_WIRE_STATUS_OK )
            return Status;
        }

    return OneWireWriteByte( DS18B20_COMMAND_CONVERT_TEMPERATURE );
    }
/*============================================================================*/