dallas.h

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//*****************************************************************************
// File Name	: dallas.c
// Title		: Dallas 1-Wire Library
// Revision		: 6
// Notes		: 
// Target MCU	: Atmel AVR series
// Editor Tabs	: 4
// 
// Revision History:
// When			Who			Rev		Description of change
// -----------	-----------	-------	-----------------------
// 24-Sep-2003	rwatson		6		Created AddressCheck, WaitUntilDone
// 23-Sep-2003	rwatson		5		Created ReadRAM, WriteRAM, PrintError, PrintROM
// 22-Sep-2003	rwatson		4		Created MatchROM, PrintROM
// 21-Sep-2003	rwatson		3		Created ReadROM, FindDevices, FindNextDevice, CRC
// 20-Sep-2003	rwatson		2		Created ReadBit, WriteBit, ReadByte, WriteByte, Reset
// 20-Sep-2003	rwatson		1		Created the program structure
//*****************************************************************************

#ifndef dallas_h
#define dallas_h

//----- Include Files ---------------------------------------------------------
#include "global.h"

//----- Defines ---------------------------------------------------------------
#define dallas_rev					6

// include configuration
#include "dallasconf.h"

// define the max number devices on
// the bus if it isn't defined yet
#ifndef DALLAS_MAX_DEVICES
#define DALLAS_MAX_DEVICES			20
#endif

// indexes of named bytes in the
// dallas address array
#define DALLAS_FAMILY_IDX			0			// family code
#define DALLAS_A0_IDX				1
#define DALLAS_A1_IDX				2
#define DALLAS_A2_IDX				3
#define DALLAS_A3_IDX				4
#define DALLAS_A4_IDX				5
#define DALLAS_A5_IDX				6
#define DALLAS_CRC_IDX				7			// crc code

// dallas return error codes
#define DALLAS_NO_ERROR				0			// all is well
#define DALLAS_PRESENCE				'h'			// presence was detected
#define DALLAS_NO_PRESENCE			'g'			// presence wasn't detected
#define DALLAS_VERIFY_ERROR			'v'			// setup verification failed
#define DALLAS_ADDRESS_ERROR		'a'			// bad address for command: either wrong family or bad CRC
#define DALLAS_CRC_ERROR			'c'			// data/return value fails CRC check
#define DALLAS_DEVICE_ERROR			'd'			// device not responding
#define DALLAS_NULL_POINTER			'p'			// dallas function passed a NULL pointer
#define DALLAS_ZERO_LEN				'z'			// ReadRAM or WriteRAM asked to read/write zero bytes
#define DALLAS_BUS_ERROR			'b'			// Bus hardware error. (wrong voltage) Possible causes:
													// - lack of pullup Resistor
													// - Other master transmitting (Dallas is not multi-master)
													// - Device failure
// ds2450 and ds18b20 errors
// defined here to work with PrintError
#define DALLAS_RESOLUTION_ERROR		'r'			// invalid resolution specified in Dallas function
#define DALLAS_INVALID_CHANNEL		'i'			// channel outside the range 'A' to 'D'
#define DALLAS_FORMAT_ERROR			'f'			// results are not in a valid format (temp sensor)

// ROM commands
#define DALLAS_READ_ROM				0x33
#define DALLAS_MATCH_ROM			0x55
#define DALLAS_SKIP_ROM				0xCC
#define DALLAS_SEARCH_ROM			0xF0
#define DALLAS_CONDITIONAL_SEARCH	0xEC
#define DALLAS_READ_MEMORY			0xAA
#define DALLAS_WRITE_MEMORY			0x55

//----- Typedefs --------------------------------------------------------------

// typedef for the rom IDs
// done so we can access the entire id or each individual byte
typedef union dallas_rom_id_U
{
	long long id;
	u08 byte[8];
} dallas_rom_id_T;

//----- Functions ---------------------------------------------------------------

// dallasInit()
//     Initializes the Dallas 1-wire Bus
//     Currently this function does nothing
void dallasInit(void);

// dallasReset()
//     performs a reset on the 1-wire bus
//     returns the presence detect (DALLAS_PRESENCE or DALLAS_NO_PRESENCE)
u08  dallasReset(void);

// dallasReadBit()
//     reads a bit from the 1-wire bus and returns this bit
//     note: global interupts are not disabled in this function
//           if using this function, use cli() and sei() before and after
u08  dallasReadBit(void);

// dallasWriteBit()
//     writes the passed in bit to the 1-wire bus
//     note: global interupts are not disabled in this function
//           if using this function, use cli() and sei() before and after
void dallasWriteBit(u08 bit);

// dallasReadByte()
//     reads a byte from the 1-wire bus and returns this byte
//     note: global interupts are disabled in this function
u08  dallasReadByte(void);

// dallasWriteByte()
//     writes the passed in byte to the 1-wire bus
//     note: global interupts are disabled in this function.
void dallasWriteByte(u08 byte);

// dallasReadRAM()
//     reads the RAM from the specified device, at the specified RAM address
//     for the specified length.  Data is stored into data variable
u08  dallasReadRAM(dallas_rom_id_T* rom_id, u16 addr, u08 len, u08 *data);

// dallasWriteRAM()
//     writes the specified data for the specified length to the RAM
//     located at the specified address of the specified device
u08  dallasWriteRAM(dallas_rom_id_T* rom_id, u16 address, u08 len, u08* data);

// dallasWaitUntilDone()
//     waits until the conversion of a dallas device is done
void dallasWaitUntilDone(void);

// dallasReadROM()
//     finds the ROM code of a device if only 1 device is
//     connected to the bus the ROM value is passed by referenced
//     returns any error that occured or DALLAS_NO_ERROR
u08 dallasReadROM(dallas_rom_id_T* rom_id);

// dallasMatchROM()
//     performs a reset on the 1-wire bus and then
//     selects the specified dallas device on the network
//     returns any error that occured or DALLAS_NO_ERROR
u08  dallasMatchROM(dallas_rom_id_T* rom_id);

// dallasPrintROM
//     prints the ROM from MSB to LSB in the format: xx xx xx xx xx xx xx xx
void dallasPrintROM(dallas_rom_id_T* rom_id);

// dallasAddressCheck()
//     checks to make sure that the rom id is in the proper family,
//     and if the crc of the id is correct
//     returns the corresponding error or DALLAS_NO_ERROR
u08  dallasAddressCheck(dallas_rom_id_T* rom_id, u08 family);

// dallasCRC()
//     calculates the CRC from the lookup table
//     returns the new crc value, which is also a global variable
u08  dallasCRC(u08 i);

// dallasFindDevices()
//     finds all the devices on the network, or up to the maximum defined value
//     stores the ids in the given array, and returns the number of devices found
u08  dallasFindDevices(dallas_rom_id_T rom_id[]);

// dallasPrintError()
//     prints the error value as well as an error message if there was an error
//     if DALLAS_NO_ERROR is passed in, nothing is done
void dallasPrintError(u08 error);

#endif