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arduino_lib_dp1wbasic

Documentation Arduino base program code

Dp1WBasic library

Description

Dp1WBasic Arduino library provide function for gething data form 1-Wire bus.

Most part of code come from original OneWire library http://www.arduino.cc/playground/Learning/OneWire !

Source code is provided as is, without any warranty.

Distributetd under CC BY v 3.0

Functions

#define NORMAL_SEARCH   0xF0
#define ALARM_SEARCH    0xEC

Dp1WBasic( uint8_t pin);

// Perform a 1-Wire reset cycle. Returns 1 if a device responds
// with a presence pulse.  Returns 0 if there is no device or the
// bus is shorted or otherwise held low for more than 250uS
uint8_t reset(void);

// Issue a 1-Wire rom select command, you do the reset first.
void select( uint8_t rom[8]);

// Issue a 1-Wire rom skip command, to address all on bus.
void skip(void);

// Write a byte. If 'power' is one then the wire is held high at
// the end for parasitically powered devices. You are responsible
// for eventually depowering it by calling depower() or doing
// another read or write.
void write(uint8_t v, uint8_t power = 0);

void write_bytes(const uint8_t *buf, uint16_t count, bool power = 0);

// Read a byte.
uint8_t read(void);

void read_bytes(uint8_t *buf, uint16_t count);

// Write a bit. The bus is always left powered at the end, see
// note in write() about that.
void write_bit(uint8_t v);

// Read a bit.
uint8_t read_bit(void);

// Stop forcing power onto the bus. You only need to do this if
// you used the 'power' flag to write() or used a write_bit() call
// and aren't about to do another read or write. You would rather
// not leave this powered if you don't have to, just in case
// someone shorts your bus.
void depower(void);

// Clear the search state so that if will start from the beginning again.
void reset_search();

// Look for the next device. Returns 1 if a new address has been
// returned. A zero might mean that the bus is shorted, there are
// no devices, or you have already retrieved all of them.  It
// might be a good idea to check the CRC to make sure you didn't
// get garbage.  The order is deterministic. You will always get
// the same devices in the same order.
uint8_t search(uint8_t *newAddr, byte searchType = NORMAL_SEARCH);

// Compute a Dallas Semiconductor 8 bit CRC, these are used in the
// ROM and scratchpad registers.
static uint8_t crc8( uint8_t *addr, uint8_t len);

// Compute the 1-Wire CRC16 and compare it against the received CRC.
//          
// @param input - Array of bytes to checksum.
// @param len - How many bytes to use.
// @param inverted_crc - The two CRC16 bytes in the received data.
//                       This should just point into the received data,
//                       *not* at a 16-bit integer.
// @return True, iff the CRC matches.
static bool check_crc16(uint8_t* input, uint16_t len, uint8_t* inverted_crc);

// Compute a Dallas Semiconductor 16 bit CRC.  This is required to check
// the integrity of data received from many 1-Wire devices.  Note that the
// CRC computed here is *not* what you'll get from the 1-Wire network,
// for two reasons:
//   1) The CRC is transmitted bitwise inverted.
//   2) Depending on the endian-ness of your processor, the binary
//      representation of the two-byte return value may have a different
//      byte order than the two bytes you get from 1-Wire.
// @param input - Array of bytes to checksum.
// @param len - How many bytes to use.
// @return The CRC16, as defined by Dallas Semiconductor.
static uint16_t crc16(uint8_t* input, uint16_t len);

Contact

Author: Dubravko Penezic

Email: dpenezic@gmail.com

Version

Actual

History

V 1.0.0 , 10.02.2012

arduino_lib_dp1wbasic.txt · Last modified: 2016/09/01 14:17 (external edit)