OneWire + DS18X20 Library
Basic functions for OneWire operations + specific DS18x20 operations
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Functions
ONEWIRE FUNCTIONS

Functions

uint8_t onewire_reset (void)
 OneWire reset. More...
 
uint8_t onewire_read_byte (void)
 read one byte More...
 
void onewire_write_byte (uint8_t data)
 write one byte More...
 
void onewire_search_init (uint8_t buffer[8])
 init rom search buffer and internal variables More...
 
uint8_t onewire_alarm_search (uint8_t buffer[8])
 scan OneWire bus for devices with active alarm flag More...
 
uint8_t onewire_search_rom (uint8_t buffer[8])
 scan OneWire bus for ROMs More...
 
uint8_t onewire_match_rom (const uint8_t rom[8])
 select device on bus More...
 
uint8_t onewire_read_rom (uint8_t rom[8])
 read ROM of device More...
 
uint8_t onewire_skip_rom (void)
 select device on bus More...
 
uint8_t onewire_crc (const uint8_t *data, uint8_t cnt)
 calculate CRC over data array, fast version, 0.3ms for 8 bytes @1MHz More...
 

Detailed Description

standard functions

Function Documentation

uint8_t onewire_reset ( void  )

OneWire reset.

reset onewire bus

Parameters
none
Returns
error code
0: no error
1: no presence pulse detected
2: bus short circuit to ground

Definition at line 19 of file onewire.c.

uint8_t onewire_read_byte ( void  )

read one byte

Parameters
none
Returns
read data byte

Definition at line 85 of file onewire.c.

void onewire_write_byte ( uint8_t  data)

write one byte

Parameters
databyte to write
Returns
none

Definition at line 98 of file onewire.c.

void onewire_search_init ( uint8_t  buffer[8])

init rom search buffer and internal variables

Parameters
buffer[8]pointer to buffer array
Returns
none

Definition at line 109 of file onewire.c.

uint8_t onewire_alarm_search ( uint8_t  buffer[8])

scan OneWire bus for devices with active alarm flag

after each call, the buffer contains the new scaned ROM code

Parameters
buffer[8]pointer to buffer array
Returns
error code
0 : new ROM code scanned successfully
1 : no bus response during reset
2 : reserved
3 : no bus response during scan
4 : last scan, no more codes available

Definition at line 118 of file onewire.c.

uint8_t onewire_search_rom ( uint8_t  buffer[8])

scan OneWire bus for ROMs

after each call, the buffer contains the new scaned ROM code

Parameters
buffer[8]pointer to buffer array
Returns
error code
0 : new ROM code scanned successfully
1 : no bus response during reset
2 : reserved
3 : no bus response during scan
4 : last scan, no more codes available

Definition at line 114 of file onewire.c.

uint8_t onewire_match_rom ( const uint8_t  rom[8])

select device on bus

Parameters
rom[8]pointer to buffer array
Returns
error code
0: code access successfully
1: no bus response during reset

Definition at line 208 of file onewire.c.

uint8_t onewire_read_rom ( uint8_t  rom[8])

read ROM of device

can only be used for a single device on bus

Parameters
rom[8]pointer to buffer array
Returns
error code
0: code access successfully
1: no bus response during reset
2: crc error

Definition at line 245 of file onewire.c.

uint8_t onewire_skip_rom ( void  )

select device on bus

can only be used for a single device on bus

Parameters
none
Returns
error code
0: code access successfully
1: no bus response during reset

Definition at line 236 of file onewire.c.

uint8_t onewire_crc ( const uint8_t *  data,
uint8_t  cnt 
)

calculate CRC over data array, fast version, 0.3ms for 8 bytes @1MHz

Parameters
*datapointer to buffer array
cntnumber of data bytes
Returns
none

Definition at line 303 of file onewire.c.