OWI.h

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// This file has been prepared for Doxygen automatic documentation generation.
#ifndef OWI_H
#define OWI_H

#include <ioavr.h>


//******************************************************************************
// Defines for CRC-functions
//******************************************************************************
#define     OWI_CRC_OK      0x00    
#define     OWI_CRC_ERROR   0x01    


//******************************************************************************
// Defines for OWI-functions
//******************************************************************************
#define     CPU_FREQUENCY   8.000


//#define     OWI_USE_INTERNAL_PULLUP


// Port configuration registers for 1-Wire buses.
// Make sure that all three registers belong to the same port.
#define     OWI_PORT        PORTA   
#define     OWI_PIN         PINA    
#define     OWI_DDR         DDRA    


//******************************************************************************
// Pin bitmasks
//******************************************************************************
#define     OWI_PIN_0       0x01
#define     OWI_PIN_1       0x02
#define     OWI_PIN_2       0x04
#define     OWI_PIN_3       0x08
#define     OWI_PIN_4       0x10
#define     OWI_PIN_5       0x20
#define     OWI_PIN_6       0x40
#define     OWI_PIN_7       0x80


//******************************************************************************
// Timing parameters
//******************************************************************************
#define     OWI_DELAY_OFFSET_CYCLES    13   

// Bit timing delays in clock cycles (= us*clock freq in MHz).
#define     OWI_DELAY_A_STD_MODE    (unsigned long)((6   * CPU_FREQUENCY) - OWI_DELAY_OFFSET_CYCLES)
#define     OWI_DELAY_B_STD_MODE    (unsigned long)((64  * CPU_FREQUENCY) - OWI_DELAY_OFFSET_CYCLES)
#define     OWI_DELAY_C_STD_MODE    (unsigned long)((60  * CPU_FREQUENCY) - OWI_DELAY_OFFSET_CYCLES)
#define     OWI_DELAY_D_STD_MODE    (unsigned long)((10  * CPU_FREQUENCY) - OWI_DELAY_OFFSET_CYCLES)
#define     OWI_DELAY_E_STD_MODE    (unsigned long)((9   * CPU_FREQUENCY) - OWI_DELAY_OFFSET_CYCLES)
#define     OWI_DELAY_F_STD_MODE    (unsigned long)((55  * CPU_FREQUENCY) - OWI_DELAY_OFFSET_CYCLES)
//#define     OWI_DELAY_G_STD_MODE  (unsigned long)((0   * CPU_FREQUENCY) - OWI_DELAY_OFFSET_CYCLES)
#define     OWI_DELAY_H_STD_MODE    (unsigned long)((480 * CPU_FREQUENCY) - OWI_DELAY_OFFSET_CYCLES)
#define     OWI_DELAY_I_STD_MODE    (unsigned long)((70  * CPU_FREQUENCY) - OWI_DELAY_OFFSET_CYCLES)
#define     OWI_DELAY_J_STD_MODE    (unsigned long)((410 * CPU_FREQUENCY) - OWI_DELAY_OFFSET_CYCLES)


//******************************************************************************
// ROM commands
//******************************************************************************
#define     OWI_ROM_READ    0x33    
#define     OWI_ROM_SKIP    0xcc    
#define     OWI_ROM_MATCH   0x55    
#define     OWI_ROM_SEARCH  0xf0    


//******************************************************************************
// Return codes
//******************************************************************************
#define     OWI_ROM_SEARCH_FINISHED     0x00   
#define     OWI_ROM_SEARCH_FAILED       0xff   


//******************************************************************************
// Macros
//******************************************************************************
#define OWI_PULL_BUS_LOW(bitMask) \
                        OWI_DDR |= (bitMask); \
                        OWI_PORT &= ~(bitMask)


#ifdef OWI_USE_INTERNAL_PULLUP            
        // Set 1-Wire pin(s) to input and enable internal pull-up resistor.
#define OWI_RELEASE_BUS(bitMask) \
                        OWI_DDR &= ~(bitMask); \
                        OWI_PORT |= (bitMask)

#else
        // Set 1-Wire pin(s) to input mode. No internal pull-up enabled.
#define OWI_RELEASE_BUS(bitMask) \
                        OWI_DDR &= ~(bitMask); \
                        OWI_PORT &= ~(bitMask)

#endif


//******************************************************************************
// Function prototypes
//******************************************************************************
void OWI_SendByte(unsigned char data, unsigned char pins);
unsigned char OWI_ReceiveByte(unsigned char pin);
void OWI_SkipRom(unsigned char pins);
void OWI_ReadRom(unsigned char * romValue, unsigned char pin);
void OWI_MatchRom(unsigned char * romValue, unsigned char pins);
unsigned char OWI_SearchRom(unsigned char * bitPattern,
                                                                         unsigned char lastDeviation, unsigned char pin);
void OWI_Init(unsigned char pins);
void OWI_WriteBit1(unsigned char pins);
void OWI_WriteBit0(unsigned char pins);
unsigned char OWI_ReadBit(unsigned char pins);
unsigned char OWI_DetectPresence(unsigned char pins);

unsigned char OWI_ComputeCRC8(unsigned char inData, unsigned char seed);
unsigned int OWI_ComputeCRC16(unsigned char inData, unsigned int seed);
unsigned char OWI_CheckRomCRC(unsigned char *romValue);

#endif // OWI_H

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