uint8_t DS18x20_Search_Rom(uint8_t *devices_found, uint8_t (*serial)[ONE_WIRE_DEVICE_NUMBER_MAX][DS18x20_SERIAL_NUM_SIZE])
{
unsigned long path, next, pos;
uint8_t bit, chk;
uint8_t cnt_bit, cnt_byte, cnt_num,tmp;
path = 0;
cnt_num = 0;
do {
/* Reset bus */
tmp = One_Wire_Reset();
if (tmp != ONE_WIRE_SUCCESS) {
return tmp;
}
One_Wire_Write_Byte(ONE_WIRE_SEARCH_ROM);
next = 0;
pos = 1;
for (cnt_byte = 0; cnt_byte != 8; cnt_byte++) {
(*serial)[cnt_num][cnt_byte] = 0;
for (cnt_bit = 0; cnt_bit != 8; cnt_bit++) {
bit = One_Wire_Read_Bit();
chk = One_Wire_Read_Bit();
if (!bit && !chk) {
if (pos & path) {
bit = 1;
} else {
next = (path & (pos - 1)) | pos;
}
pos <<= 1;
}
One_Wire_Write_Bit(bit);
if (bit != 0) {
(*serial)[cnt_num][cnt_byte] |= (1 << cnt_bit);
}
}
}
path = next;
cnt_num++;
} while(path);
/* Write number of devices */
*devices_found = cnt_num;
return ONE_WIRE_SUCCESS;
}
uint8_t DS18x20_Search_Rom_One_Device(uint8_t* serial[DS18x20_SERIAL_NUM_SIZE])
{
uint8_t cnt_bits;
uint8_t cnt_bytes;
uint8_t tmp;
uint8_t tmp2 = 0;
uint8_t dev_cnt = 0;
/* Reset bus */
tmp = One_Wire_Reset();
if (tmp != ONE_WIRE_SUCCESS) {
return tmp;
}
One_Wire_Write_Byte(ONE_WIRE_SEARCH_ROM);
for (cnt_bytes = 0; cnt_bytes != 8; cnt_bytes++) {
for (cnt_bits = 0; cnt_bits != 8; cnt_bits++) {
tmp = One_Wire_Read_Bit();
if (One_Wire_Read_Bit() == tmp) {
dev_cnt++;
}
One_Wire_Write_Bit(tmp);
if (tmp) {
tmp2 |= (1 << cnt_bits);
}
}
*serial[cnt_bytes]=tmp2;
tmp2=0;
}
/* Verify CRC checksum */
if (Crc8Dallas(DS18x20_SERIAL_NUM_SIZE, *serial)) {
return ONE_WIRE_CRC_ERROR;
}
return ONE_WIRE_SUCCESS;
}
void One_Wire_Write_Byte(unsigned char Byte,GPIO_TypeDef * GPIOx, u16 PINx)
{
unsigned char cnt;
for (cnt=0;cnt!=8;cnt++) One_Wire_Write_Bit(Byte&(1<<cnt),GPIOx, PINx);
}