uint8_t ow_rom_search( uint8_t diff, uint8_t *id )
{
uint8_t i, j, next_diff;
uint8_t b;
if( ow_reset() ) {
return OW_PRESENCE_ERR; // error, no device found <--- early exit!
}
ow_byte_wr( OW_SEARCH_ROM ); // ROM search command
next_diff = OW_LAST_DEVICE; // unchanged on last device
i = OW_ROMCODE_SIZE * 8; // 8 bytes
do {
j = 8; // 8 bits
do {
b = ow_bit_io( 1 ); // read bit
if( ow_bit_io( 1 ) ) { // read complement bit
if( b ) { // 0b11
return OW_DATA_ERR; // data error <--- early exit!
}
}
else {
if( !b ) { // 0b00 = 2 devices
if( diff > i || ((*id & 1) && diff != i) ) {
b = 1; // now 1
next_diff = i; // next pass 0
}
}
}
ow_bit_io( b ); // write bit
*id >>= 1;
if( b ) {
*id |= 0x80; // store bit
}
i--;
} while( --j );
id++; // next byte
} while( i );
return next_diff; // to continue search
}
/* get power status of DS18x20
input : id = rom_code
returns: DS18X20_POWER_EXTERN or DS18X20_POWER_PARASITE */
uint8_t DS18X20_get_power_status(uint8_t id[])
{
uint8_t pstat;
ow_reset();
ow_command(DS18X20_READ_POWER_SUPPLY, id);
pstat=ow_bit_io(1); // pstat 0=is parasite/ !=0 ext. powered
ow_reset();
return (pstat) ? DS18X20_POWER_EXTERN:DS18X20_POWER_PARASITE;
}
uint8_t ow_byte_wr( uint8_t b )
{
uint8_t i = 8, j;
do {
j = ow_bit_io( b & 1 );
b >>= 1;
if( j ) b |= 0x80;
} while( --i );
return b;
}
/***************************************
*
*
-***************************************/
uint8_t
ow_rom_search( uint8_t diff, uint8_t *id )
{ uint8_t i, j, next_diff;
uint8_t b;
if( ow_reset() ) return OW_PRESENCE_ERR;/* error, no device found*/
ow_byte_wr( OW_SEARCH_ROM ); /*ROM search command*/
next_diff = OW_LAST_DEVICE; /* unchanged on last device*/
i = OW_ROMCODE_SIZE * 8; /* 8 bytes*/
do {
j = 8; /* 8 bits*/
do{
b = ow_bit_io( 1 ); /* read bit*/
if( ow_bit_io( 1 ) ) {
/* read complement bit*/
if( b )/* 11*/ return OW_DATA_ERR; /* data error*/
}
else {
if( !b ) { /* 00 = 2 devices*/
if( diff > i || ((*id & 1) && diff != i) ) {
b = 1; /* now 1*/
next_diff = i; /* next pass 0*/
}
}
}
ow_bit_io( b ); /* write bit*/
*id >>= 1;
if( b ) *id |= 0x80;/* store bit*/
i--;
}
while( --j );
id++; /* next byte*/
}
while( i ); /* to continue search*/
return next_diff;
}
u8 ow_byte_write(u8 b)
{
u8 i;
for(i=8; i; i--)
{
u8 j;
j = ow_bit_io(b&1);
delay_us(5);
b >>= 1;
if (j)
{
b |= 0x80;
}
}
return b;
}
