File content as of revision 15:f6cb0d906fb6:

/******************************************************************//**
* @file OneWireMaster.cpp
*
* @author Justin Jordan
*
* @version 0.0.0
*
* Started: 08FEB16
*
* Updated: 
*
* @brief Header file for functions shared between masters, that should
* be implemented only once.
***********************************************************************
* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
*
* 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 MAXIM INTEGRATED 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.
*
* Except as contained in this notice, the name of Maxim Integrated
* Products, Inc. shall not be used except as stated in the Maxim Integrated
* Products, Inc. Branding Policy.
*
* The mere transfer of this software does not imply any licenses
* of trade secrets, proprietary technology, copyrights, patents,
* trademarks, maskwork rights, or any other form of intellectual
* property whatsoever. Maxim Integrated Products, Inc. retains all
* ownership rights.
**********************************************************************/


#include "OneWireMaster.h"


//*********************************************************************
void OneWireMaster::OWWriteBit(uint8_t sendbit)
{
    OWTouchBit(sendbit);
}


//*********************************************************************
uint8_t OneWireMaster::OWReadBit()
{
    return(OWTouchBit(0x01)); 
}


//*********************************************************************
uint8_t OneWireMaster::OWTouchByte(uint8_t sendbyte)
{
    uint8_t rtn_val;

    if (sendbyte == 0xFF) 
    {
        rtn_val = OWReadByte();
    } 
    else 
    {
        OWWriteByte(sendbyte);
        rtn_val = sendbyte;
    }
    
    return(rtn_val);
}


//*********************************************************************
void OneWireMaster::OWBlock(uint8_t *tran_buf, uint8_t tran_len)
{
    uint8_t i;
    
    for (i = 0; i < tran_len; i++)
    {
        tran_buf[i] = OWTouchByte(tran_buf[i]);
    }
}


//*********************************************************************
void OneWireMaster::OWWriteBlock(const uint8_t *tran_buf, uint8_t tran_len)
{
    uint8_t idx;
    
    for(idx = 0; idx < tran_len; idx++)
    {
        OWWriteByte(tran_buf[idx]);
    }
}
    
    
//*********************************************************************
void OneWireMaster::OWReadBlock(uint8_t *recv_buf, uint8_t recv_len)
{
    uint8_t idx;
    
    for(idx = 0; idx < recv_len; idx++)
    {
        recv_buf[idx] = OWReadByte();
    }
}


//*********************************************************************
bool OneWireMaster::OWFirst(void)
{
    // reset the search state
    _last_discrepancy = 0;
    _last_device_flag = false;
    _last_family_discrepancy = 0;

   return OWSearch();  
}


//*********************************************************************
bool OneWireMaster::OWNext(void)
{
    // leave the search state alone
    return OWSearch();
}


//*********************************************************************
bool OneWireMaster::OWVerify(void)
{
    bool rtn_val = false;

    uint8_t rom_backup[8];
    uint8_t i,rslt,ld_backup,ldf_backup,lfd_backup;

    // keep a backup copy of the current state
    for (i = 0; i < 8; i++)
    {
        rom_backup[i] = _rom_number[i];
    }
    
    ld_backup = _last_discrepancy;
    ldf_backup = _last_device_flag;
    lfd_backup = _last_family_discrepancy;

    // set search to find the same device
    _last_discrepancy = 64;
    _last_device_flag = false;

    if (OWSearch()) 
    {
        // check if same device found
        rslt = true;
        for (i = 0; i < 8; i++) 
        {
            if (rom_backup[i] != _rom_number[i]) 
            {
                rslt = false;
                break;
            }
        }
    } 
    else
    {
        rslt = false;
    }

    // restore the search state
    for (i = 0; i < 8; i++)
    {
        _rom_number[i] = rom_backup[i];
    }
    
    _last_discrepancy = ld_backup;
    _last_device_flag = ldf_backup;
    _last_family_discrepancy = lfd_backup;
    
    // return the result of the verify
    rtn_val = rslt;
    
    return(rtn_val);
}


//*********************************************************************
void OneWireMaster::OWTargetSetup(uint8_t family_code)
{
    uint8_t i;

    // set the search state to find SearchFamily type devices
    _rom_number[0] = family_code;
    for (i = 1; i < 8; i++)
    {
        _rom_number[i] = 0;
    }
    
    _last_discrepancy = 64;
    _last_family_discrepancy = 0;
    _last_device_flag = false;
}


//*********************************************************************
void OneWireMaster::OWFamilySkipSetup(void)
{
    // set the Last discrepancy to last family discrepancy
    _last_discrepancy = _last_family_discrepancy;
    
    // clear the last family discrpepancy
    _last_family_discrepancy = 0;
    
    // check for end of list
    if (_last_discrepancy == 0) 
    {
        _last_device_flag = true;
    }
}


//*********************************************************************
bool OneWireMaster::OWReadROM(void)
{
    bool rtn_val = false;
    
    if(!OWReset())
    {
        rtn_val = false;
    }
    else
    {
        if(!OWWriteByte(READ_ROM))
        {
            rtn_val = false;
        }
        else
        {
            OWReadBlock(_rom_number, ROMnumberLen);
            rtn_val = true;
        }
    }
    
    return rtn_val;
}
    

//*********************************************************************    
bool OneWireMaster::OWSkipROM(void)
{
    bool rtn_val = false;
    
    if(!OWReset())
    {
        rtn_val = false;
    }
    else
    {
        if(!OWWriteByte(SKIP_ROM))
        {
            rtn_val = false;
        }
        else
        {
            rtn_val = true;
        }
    }
    
    return rtn_val;
}
    

//*********************************************************************    
bool OneWireMaster::OWMatchROM(void)
{
    bool rtn_val = false;
    uint8_t idx;
    
    if(!OWReset())
    {
        rtn_val = false;
    }
    else
    {
        if(!OWWriteByte(MATCH_ROM))
        {
            rtn_val = false;
        }
        else
        {
            for(idx = 0; idx < ROMnumberLen; idx++)
            {
                OWWriteByte(_rom_number[idx]);
            }
            rtn_val = true;
        }
    }
    
    return rtn_val;
}
    

//*********************************************************************    
bool OneWireMaster::OWOverdriveSkipROM(void)
{
    bool rtn_val = false;
    
    if(!OWReset())
    {
        rtn_val = false;
    }
    else
    {
        if(!OWWriteByte(OVERDRIVE_SKIP))
        {
            rtn_val = false;
        }
        else
        {
            //change speed for subsequent comands
            OWSpeed(SPEED_OVERDRIVE);
            rtn_val = true;
        }
    }
    
    return rtn_val;
}
    

//*********************************************************************    
bool OneWireMaster::OWOverdriveMatchROM(void)
{
    bool rtn_val = false;
    uint8_t idx;
    
    if(!OWReset())
    {
        rtn_val = false;
    }
    else
    {
        if(!OWWriteByte(OVERDRIVE_MATCH))
        {
            rtn_val = false;
        }
        else
        {
            //change speed before sending ROM number
            OWSpeed(SPEED_OVERDRIVE);
            
            for(idx = 0; idx < ROMnumberLen; idx++)
            {
                OWWriteByte(_rom_number[idx]);
            }
            rtn_val = true;
        }
    }
    
    return rtn_val;
}
    

//*********************************************************************    
bool OneWireMaster::OWResume(void)
{
    bool rtn_val = false;
    
    if(!OWReset())
    {
        rtn_val = false;
    }
    else
    {
        if(!OWWriteByte(RESUME))
        {
            rtn_val = false;
        }
        else
        {
            rtn_val = true;
        }
    }
    
    return rtn_val;
}


//*********************************************************************
const uint8_t (&OneWireMaster::OWgetROMnumber() const)[ROMnumberLen]
{
    return _rom_number;
}


//*********************************************************************
uint8_t OneWireMaster::OWCalc_crc8(uint8_t data, uint8_t crc8)
{
    unsigned char i;

    // See Application Note 27
    crc8 = crc8 ^ data;
    for (i = 0; i < 8; ++i) 
    {
        if (crc8 & 1)
        {
            crc8 = (crc8 >> 1) ^ 0x8c;
        }
        else
        {
            crc8 = (crc8 >> 1);
        }
    }

    return crc8;
}