u8 DS18B20StartMeasure(u8 pin, u8 num, u8 resolution)
{
u8 res, busy = LOW;
u8 temp_lsb, temp_msb;
u16 temp;
switch (resolution)
{
case RES12BIT: res = 0b01100000; break; // 12-bit resolution
case RES11BIT: res = 0b01000000; break; // 11-bit resolution
case RES10BIT: res = 0b00100000; break; // 10-bit resolution
case RES9BIT: res = 0b00000000; break; // 9-bit resolution
default: res = 0b00000000; break; // 9-bit resolution
/// NB: The power-up default of these bits is R0 = 1 and R1 = 1 (12-bit resolution)
}
if (!DS18B20Configure(pin, num, 0, 0, res)) return FALSE; // no alarm
if (OneWireReset(pin)) return FALSE;
if (num == SKIPROM)
{
// Skip ROM, address all devices
OneWireWrite(pin, SKIPROM);
}
else
{
// Talk to a particular device
if (!DS18B20MatchRom(pin, num)) return FALSE;
}
OneWireWrite(pin, CONVERT_T); // Start temperature conversion
return TRUE;
}
/*JSON{
"type" : "method",
"class" : "OneWire",
"name" : "select",
"generate" : "jswrap_onewire_select",
"params" : [
["rom","JsVar","The device to select (get this using `OneWire.search()`)"]
]
}
Select a ROM - always performs a reset first
*/
void jswrap_onewire_select(JsVar *parent, JsVar *rom) {
Pin pin = onewire_getpin(parent);
if (!jshIsPinValid(pin)) return;
if (!jsvIsString(rom) || jsvGetStringLength(rom)!=16) {
jsExceptionHere(JSET_TYPEERROR, "Invalid OneWire device address %q", rom);
return;
}
// perform a reset
OneWireReset(pin);
// decode the address
unsigned long long romdata = 0;
JsvStringIterator it;
jsvStringIteratorNew(&it, rom, 0);
int i;
for (i=0;i<8;i++) {
char b[3];
b[0] = jsvStringIteratorGetChar(&it);
jsvStringIteratorNext(&it);
b[1] = jsvStringIteratorGetChar(&it);
jsvStringIteratorNext(&it);
b[2] = 0;
romdata = romdata | (((unsigned long long)stringToIntWithRadix(b,16,NULL,NULL)) << (i*8));
}
jsvStringIteratorFree(&it);
// finally write data out
OneWireWrite(pin, 8, 0x55);
OneWireWrite(pin, 64, romdata);
}
void OneWireSearchRom(void) {
unsigned char bit,bit_complementary,pozycja,buffer[NUM_OF_THERMS];
for(unsigned char i=0;i < NUM_OF_THERMS;i++) {
buffer[i]=0;
}
for(unsigned char i=0;i < NUM_OF_THERMS;i++) {
pozycja=0;
if (!OneWireReset()) return;
OneWireWriteByte(0xF0);
for(unsigned char bitNo=0;bitNo<64;bitNo++) {
bit=OneWireReadBit();
bit_complementary=OneWireReadBit();
if ((!(bit|bit_complementary))&1) {
if(buffer[pozycja+1]==0) {
buffer[pozycja]++;
}
OneWireWriteBit((buffer[pozycja]-1));
ROM[i][bitNo/8]|=((buffer[pozycja]-1))<<(bitNo%8);
pozycja++;
}
else {
OneWireWriteBit(bit);
ROM[i][bitNo/8]|=bit<<(bitNo%8);
}
}
while(buffer[pozycja-1]==2) {
buffer[pozycja]=0;
pozycja--;
}
}
}
u8 DS18B20MatchRom(u8 pin, u8 num)
{
u8 i;
if (OneWireReset(pin)) return FALSE;
OneWireWrite(pin, MATCHROM); // Match Rom
for (i = 0; i < 8; i++) // Send the Address ROM Code.
OneWireWrite(pin, DS18B20Rom[num][i]);
return TRUE;
}
void DS18B20ReadRom(u8 pin, u8 *romcode)
{
u8 i;
if (!OneWireReset(pin))
{
OneWireWrite(pin, READROM);
for (i = 0; i < 8; i++) // Reads the ROM Code from a device
romcode[i] = OneWireRead(pin);
}
}
int ds18b20_SetResolution(char resolution)
{
if(resolution == 12){
resolution = 0x7F;
}
else if(resolution == 11){
resolution = 0x5F;
}
else if(resolution == 10){
resolution = 0x3F;
}
else if(resolution == 9){
resolution = 0x1F;
}
else{
resolution = 0x7F;
}
for(int i=0;i < NUM_OF_THERMS;i++){
if (!OneWireReset()) {return 0;}
if(NUM_OF_THERMS > 1){
OneWireWriteByte(0x55);
for(int j=0;j<8;j++){
OneWireWriteByte(ROM[i][j]);
}
} else{
OneWireWriteByte(0xcc);
}
OneWireWriteByte(0x4E);
OneWireWriteByte(0x00);
OneWireWriteByte(0x00);
OneWireWriteByte(resolution);
if (!OneWireReset()) {return 0;}
OneWireWriteByte(0x55);
for(int j=0;j<8;j++){
OneWireWriteByte(ROM[i][j]);
}
OneWireWriteByte(0x48);
_delay_ms(10);
}
return 1;
}
int ds18b20_Read(){
for(int i=0;i < NUM_OF_THERMS;i++){
unsigned char scratchpad[2];
if (!OneWireReset()) {return 0;}
if(NUM_OF_THERMS > 1){
OneWireWriteByte(0x55);
for(int j=0;j<8;j++){
OneWireWriteByte(ROM[i][j]);
}
} else{
OneWireWriteByte(0xcc);
}
OneWireWriteByte(0xBE);
for(int k=0; k<2; k++) scratchpad[k] = OneWireReadByte();
temperatures[i]= ((scratchpad[1] << 8) + scratchpad[0]) / 16.0;
}
return 1;
}
u8 DS18B20Configure(u8 pin, u8 num, u8 TH, u8 TL, u8 config)
{
if (OneWireReset(pin)) return FALSE;
if (num == SKIPROM)
{
// Skip ROM, address all devices
OneWireWrite(pin, SKIPROM);
}
else
{
// Talk to a particular device
DS18B20MatchRom(pin, num);
}
OneWireWrite(pin, WRITE_SCRATCHPAD); // Allows the master to write 3 bytes of data to the scratchpad
OneWireWrite(pin, TH); // The first data byte is written into the TH register (byte 2 of the scratchpad)
OneWireWrite(pin, TL); // The second byte is written into the TL register (byte 3)
OneWireWrite(pin, config); // The third byte is written into the configuration register (byte 4)
return TRUE;
}
void DS18B20Find(u8 pin)
{
u8 m;
if (!OneWireReset(pin)) // Detects presence of devices
{
if (DS18B20GetFirst(pin)) // Begins when at least one part is found
{
numROMs=0;
do {
numROMs++;
// serialprint("Device #");
for(m = 0; m < 8; m++)
{
// Identifies ROM number on found device
DS18B20Rom[numROMs][m] = ROM[m];
}
//Continues until no additional devices are found
} while (DS18B20GetNext(pin)&&(numROMs<10));
}
}
}
u8 DS18B20Read(u8 pin, u8 num, u8 resolution, DS18B20_Temperature * t)
{
u8 res, busy = LOW;
u8 temp_lsb, temp_msb;
u16 temp;
switch (resolution)
{
case RES12BIT: res = 0b01100000; break; // 12-bit resolution
case RES11BIT: res = 0b01000000; break; // 11-bit resolution
case RES10BIT: res = 0b00100000; break; // 10-bit resolution
case RES9BIT: res = 0b00000000; break; // 9-bit resolution
default: res = 0b00000000; break; // 9-bit resolution
/// NB: The power-up default of these bits is R0 = 1 and R1 = 1 (12-bit resolution)
}
if (!DS18B20Configure(pin, num, 0, 0, res)) return FALSE; // no alarm
if (OneWireReset(pin)) return FALSE;
if (num == SKIPROM)
{
// Skip ROM, address all devices
OneWireWrite(pin, SKIPROM);
}
else
{
// Talk to a particular device
if (!DS18B20MatchRom(pin, num)) return FALSE;
}
OneWireWrite(pin, CONVERT_T); // Start temperature conversion
while (busy == LOW) // Wait while busy ( = bus is low)
busy = OneWireRead(pin);
if (OneWireReset(pin)) return FALSE;
if (num == SKIPROM)
{
// Skip ROM, address all devices
OneWireWrite(pin, SKIPROM);
}
else
{
// Talk to a particular device
if (!DS18B20MatchRom(pin, num)) return FALSE;
}
OneWireWrite(pin, READ_SCRATCHPAD);// Read scratchpad
temp_lsb = OneWireRead(pin); // byte 0 of scratchpad : temperature lsb
temp_msb = OneWireRead(pin); // byte 1 of scratchpad : temperature msb
if (OneWireReset(pin)) return FALSE;
// Calculation
// ---------------------------------------------------------------------
// Temperature Register Format
// BIT7 BIT6 BIT5 BIT4 BIT3 BIT2 BIT1 BIT0
// LS BYTE 2^3 2^2 2^1 2^0 2^-1 2^-2 2^-3 2^-4
// BIT15 BIT14 BIT13 BIT12 BIT11 BIT10 BIT9 BIT8
// MS BYTE S S S S S 2^6 2^5 2^4
// S = SIGN
temp = temp_msb;
temp = (temp << 8) + temp_lsb; // combine msb & lsb into 16 bit variable
if (temp_msb & 0b11111000) // test if sign is set, i.e. negative
{
t->sign = 1;
temp = (temp ^ 0xFFFF) + 1; // 2's complement conversion
}
else
{
t->sign = 0;
}
t->integer = (temp >> 4) & 0x7F; // fractional part is removed, leaving only integer part
/*
t->fraction = 0; // fractional part
if (BitRead(temp, 0)) t->fraction += 625;
if (BitRead(temp, 1)) t->fraction += 1250;
if (BitRead(temp, 2)) t->fraction += 2500;
if (BitRead(temp, 3)) t->fraction += 5000;
*/
t->fraction = (temp & 0x0F) * 625;
t->fraction /= 100; // two digits after decimal
return TRUE;
}
u8 DS18B20ReadMeasure(u8 pin, u8 num, DS18B20_Temperature * t)
{
u8 res, busy = LOW;
u8 temp_lsb, temp_msb;
u16 temp;
if (OneWireReset(pin)) return FALSE;
if (num == SKIPROM)
{
// Skip ROM, address all devices
OneWireWrite(pin, SKIPROM);
}
else
{
// Talk to a particular device
if (!DS18B20MatchRom(pin, num)) return FALSE;
}
OneWireWrite(pin, READ_SCRATCHPAD);// Read scratchpad
temp_lsb = OneWireRead(pin); // byte 0 of scratchpad : temperature lsb
temp_msb = OneWireRead(pin); // byte 1 of scratchpad : temperature msb
if (OneWireReset(pin)) return FALSE;
// Calculation
// ---------------------------------------------------------------------
// Temperature Register Format
// BIT7 BIT6 BIT5 BIT4 BIT3 BIT2 BIT1 BIT0
// LS BYTE 2^3 2^2 2^1 2^0 2^-1 2^-2 2^-3 2^-4
// BIT15 BIT14 BIT13 BIT12 BIT11 BIT10 BIT9 BIT8
// MS BYTE S S S S S 2^6 2^5 2^4
// S = SIGN
temp = temp_msb;
temp = (temp << 8) + temp_lsb; // combine msb & lsb into 16 bit variable
if (temp_msb & 0b11111000) // test if sign is set, i.e. negative
{
t->sign = 1;
temp = (temp ^ 0xFFFF) + 1; // 2's complement conversion
}
else
{
t->sign = 0;
}
t->integer = (temp >> 4) & 0x7F; // fractional part is removed, leaving only integer part
/*
t->fraction = 0; // fractional part
if (BitRead(temp, 0)) t->fraction += 625;
if (BitRead(temp, 1)) t->fraction += 1250;
if (BitRead(temp, 2)) t->fraction += 2500;
if (BitRead(temp, 3)) t->fraction += 5000;
*/
t->fraction = (temp & 0x0F) * 625;
t->fraction /= 100; // two digits after decimal
return TRUE;
}
/*JSON{
"type" : "method",
"class" : "OneWire",
"name" : "reset",
"generate" : "jswrap_onewire_reset",
"return" : ["bool","True is a device was present (it held the bus low)"]
}
Perform a reset cycle
*/
bool jswrap_onewire_reset(JsVar *parent) {
Pin pin = onewire_getpin(parent);
if (!jshIsPinValid(pin)) return 0;
return OneWireReset(pin);
}
u8 DS18B20Read(u8 pin, u8 num, u8 resolution, TEMPERATURE * t)
{
u8 res, busy = 0;
u8 temp_lsb, temp_msb;
switch (resolution)
{
case RES12BIT: res = Bin(01100000); break; // 12-bit resolution
case RES11BIT: res = Bin(01000000); break; // 11-bit resolution
case RES10BIT: res = Bin(00100000); break; // 10-bit resolution
case RES9BIT: res = Bin(00000000); break; // 9-bit resolution
default: res = Bin(00000000); break; // 9-bit resolution
/// NB: The power-up default of these bits is R0 = 1 and R1 = 1 (12-bit resolution)
}
DS18B20Configure(pin, num, 0, 0, res); // no alarm
if (OneWireReset(pin)) return FALSE;
if (num == SKIPROM)
{
// Skip ROM, address all devices
OneWireWrite(pin, SKIPROM);
}
else
{
// Talk to a particular device
DS18B20MatchRom(pin, num);
}
OneWireWrite(pin, CONVERT_T); // Start temperature conversion
while (busy == 0) // Wait while busy ( = bus is low)
busy = OneWireRead(pin);
if (OneWireReset(pin)) return FALSE;
if (num == SKIPROM)
{
// Skip ROM, address all devices
OneWireWrite(pin, SKIPROM);
}
else
{
// Talk to a particular device
DS18B20MatchRom(pin, num);
}
OneWireWrite(pin, READ_SCRATCHPAD);// Read scratchpad
temp_lsb = OneWireRead(pin); // byte 0 of scratchpad : temperature lsb
temp_msb = OneWireRead(pin); // byte 1 of scratchpad : temperature msb
OneWireReset(pin);
// Calculation
// ---------------------------------------------------------------------
// Temperature Register Format
// BIT7 BIT6 BIT5 BIT4 BIT3 BIT2 BIT1 BIT0
// LS BYTE 2^3 2^2 2^1 2^0 2^-1 2^-2 2^-3 2^-4
// BIT15 BIT14 BIT13 BIT12 BIT11 BIT10 BIT9 BIT8
// MS BYTE S S S S S 2^6 2^5 2^4
// S = SIGN
if (temp_msb >= Bin(11111000)) // test if temperature is negative
{
t->sign = 1;
temp_msb -= Bin(11111000);
}
else
{
t->sign = 0;
}
t->integer = temp_lsb >> 4; // fractional part is removed, it remains only integer part
t->integer |= (temp_msb << 4); // integer part from temp_msb is added
t->fraction = 0; // fractional part (
if (BitRead(temp_lsb, 0)) t->fraction += 625;
if (BitRead(temp_lsb, 1)) t->fraction += 1250;
if (BitRead(temp_lsb, 2)) t->fraction += 2500;
if (BitRead(temp_lsb, 3)) t->fraction += 5000;
t->fraction /= 100; // two digits after decimal
return TRUE;
}
unsigned char ds18b20_ConvertT(void){
if (!OneWireReset()) return 0;
OneWireWriteByte(0xcc); // SKIP ROM
OneWireWriteByte(0x44); // CONVERT T
return -1;
}
/*JSON{
"type" : "method",
"class" : "OneWire",
"name" : "search",
"generate" : "jswrap_onewire_search",
"params" : [
["command","int32","(Optional) command byte. If not specified (or zero), this defaults to 0xF0. This can could be set to 0xEC to perform a DS18B20 'Alarm Search Command'"]
],
"return" : ["JsVar","An array of devices that were found"]
}
Search for devices
*/
JsVar *jswrap_onewire_search(JsVar *parent, int command) {
// search - code from http://www.maximintegrated.com/app-notes/index.mvp/id/187
Pin pin = onewire_getpin(parent);
if (!jshIsPinValid(pin)) return 0;
JsVar *array = jsvNewEmptyArray();
if (!array) return 0;
if (command<=0 || command>255)
command = 0xF0; // normal search command
// global search state
unsigned char ROM_NO[8];
int LastDiscrepancy;
int LastFamilyDiscrepancy;
int LastDeviceFlag;
// reset the search state
LastDiscrepancy = 0;
LastDeviceFlag = FALSE;
LastFamilyDiscrepancy = 0;
int search_result = true;
while (search_result) {
int id_bit_number;
int last_zero, rom_byte_number;
unsigned char id_bit, cmp_id_bit;
unsigned char rom_byte_mask, search_direction;
// initialize for search
id_bit_number = 1;
last_zero = 0;
rom_byte_number = 0;
rom_byte_mask = 1;
search_result = 0;
// if the last call was not the last one
if (!LastDeviceFlag)
{
// 1-Wire reset
if (!OneWireReset(pin))
{
// reset the search
LastDiscrepancy = 0;
LastDeviceFlag = FALSE;
LastFamilyDiscrepancy = 0;
return array;
}
// issue the search command
OneWireWrite(pin, 8, (unsigned long long)command);
// loop to do the search
do
{
// read a bit and its complement
id_bit = (unsigned char)OneWireRead(pin, 1);
cmp_id_bit = (unsigned char)OneWireRead(pin, 1);
// check for no devices on 1-wire
if ((id_bit == 1) && (cmp_id_bit == 1))
break;
else
{
// all devices coupled have 0 or 1
if (id_bit != cmp_id_bit)
search_direction = id_bit; // bit write value for search
else
{
// if this discrepancy if before the Last Discrepancy
// on a previous next then pick the same as last time
if (id_bit_number < LastDiscrepancy)
search_direction = ((ROM_NO[rom_byte_number] & rom_byte_mask) > 0);
else
// if equal to last pick 1, if not then pick 0
search_direction = (id_bit_number == LastDiscrepancy);
// if 0 was picked then record its position in LastZero
if (search_direction == 0)
{
last_zero = id_bit_number;
// check for Last discrepancy in family
if (last_zero < 9)
LastFamilyDiscrepancy = last_zero;
}
}
// set or clear the bit in the ROM byte rom_byte_number
// with mask rom_byte_mask
if (search_direction == 1)
ROM_NO[rom_byte_number] |= rom_byte_mask;
else
ROM_NO[rom_byte_number] &= (unsigned char)~rom_byte_mask;
// serial number search direction write bit
OneWireWrite(pin, 1, search_direction);
// increment the byte counter id_bit_number
// and shift the mask rom_byte_mask
id_bit_number++;
rom_byte_mask = (unsigned char)(rom_byte_mask << 1);
// if the mask is 0 then go to new SerialNum byte rom_byte_number and reset mask
if (rom_byte_mask == 0)
{
rom_byte_number++;
rom_byte_mask = 1;
}
}
}
while(rom_byte_number < 8); // loop until through all ROM bytes 0-7
// if the search was successful then
if (!((id_bit_number < 65)))
{
// search successful so set LastDiscrepancy,LastDeviceFlag,search_result
LastDiscrepancy = last_zero;
// check for last device
if (LastDiscrepancy == 0)
LastDeviceFlag = TRUE;
search_result = TRUE;
}
}
// if no device found then reset counters so next 'search' will be like a first
if (!search_result || !ROM_NO[0])
{
LastDiscrepancy = 0;
LastDeviceFlag = FALSE;
LastFamilyDiscrepancy = 0;
search_result = FALSE;
}
if (search_result) {
int i;
char buf[17];
for (i=0;i<8;i++) {
buf[i*2] = itoch((ROM_NO[i]>>4) & 15);
buf[i*2+1] = itoch(ROM_NO[i] & 15);
}
buf[16]=0;
jsvArrayPushAndUnLock(array, jsvNewFromString(buf));
}
NOT_USED(LastFamilyDiscrepancy);
}
return array;
}
u8 DS18B20GetNext(u8 pin)
{
u8 m = 1; // ROM Bit index
u8 n = 0; // ROM Byte index
u8 k = 1; // bit mask
u8 x = 0;
u8 discrepMarker = 0; // discrepancy marker
u8 g; // Output bit
u8 nxt; // return value
int flag;
nxt = FALSE; // set the next flag to false
dowcrc = 0; // reset the dowcrc
flag = OneWireReset(pin); // reset the 1-wire
if(flag||doneFlag) // no parts -> return false
{
lastDiscrep = 0; // reset the search
return FALSE;
}
// send SearchROM command for all eight bytes
OneWireWrite(pin, SEARCHROM);
do {
x = 0;
if(OneWireReadBit(pin) == 1) x = 2;
//myDelay_10us(12);
if(OneWireReadBit(pin) == 1 ) x |= 1;
if(x == 3)
break;
else
{
if(x > 0) // all devices coupled have 0 or 1
g = x >> 1; // bit write value for search
else
{
// if this discrepancy is before the last
// discrepancy on a previous Next then pick
// the same as last time
if(m < lastDiscrep)
g = ( (ROM[n] & k) > 0);
else // if equal to last pick 1
g = (m == lastDiscrep); // if not then pick 0
// if 0 was picked then record position with mask k
if (g == 0) discrepMarker = m;
}
if (g == 1) // isolate bit in ROM[n] with mask k
ROM[n] |= k;
else
ROM[n] &= ~k;
OneWireWriteBit(pin, g); // ROM search write
m++; // increment bit counter m
k = k << 1; // and shift the bit mask k
if(k == 0) // if the mask is 0 then go to new ROM
{ // byte n and reset mask
DS18B20_crc(ROM[n]); // accumulate the CRC
n++;
k++;
}
}
} while (n < 8); // loop until through all ROM bytes 0-7
if(m < 65 || dowcrc) // if search was unsuccessful then
lastDiscrep=0; // reset the last discrepancy to 0
else // search was successful, so set lastDiscrep, lastOne, nxt
{
lastDiscrep = discrepMarker;
doneFlag = (lastDiscrep == 0);
nxt = TRUE; // indicates search is not complete yet, more parts remain
}
return nxt;
}
/**
* The 'OneWireSearch' function does a general search. This function continues from
* the previous search state. The search state can be reset by using the
* 'OneWireFirst' function.
*
* @retval true When a 1-Wire device was found and its Serial Number placed in
* the global ROM
* @retval false When no new device was found. Either the last search was
* the last device or there are no devices on the 1-Wire Net.
*/
unsigned char OneWireSearch(void)
{
unsigned char id_bit_number;
unsigned char last_zero, rom_byte_number, search_result;
unsigned char id_bit, cmp_id_bit;
unsigned char rom_byte_mask, search_direction, status;
// initialize for search
id_bit_number = 1;
last_zero = 0;
rom_byte_number = 0;
rom_byte_mask = 1;
search_result = false;
// if the last call was not the last one
if (!LastDeviceFlag)
{
// 1-Wire reset
if (!OneWireReset())
{
// reset the search
LastDiscrepancy = 0;
LastDeviceFlag = false;
LastFamilyDiscrepancy = 0;
return false;
}
// issue the search command
OneWireWriteByte(0xF0);
// loop to do the search
do
{
// if this discrepancy if before the Last Discrepancy
// on a previous next then pick the same as last time
if (id_bit_number < LastDiscrepancy)
{
if ((ROM_NO[rom_byte_number] & rom_byte_mask) > 0)
search_direction = 1;
else
search_direction = 0;
}
else
{
// if equal to last pick 1, if not then pick 0
if (id_bit_number == LastDiscrepancy)
search_direction = 1;
else
search_direction = 0;
}
// Perform a triple operation on the DS2482 which will perform
// 2 read bits and 1 write bit
status = DS2482SearchTriplet(search_direction);
// check bit results in status byte
id_bit = ((status & DS2482_STATUS_SBR) == DS2482_STATUS_SBR);
cmp_id_bit = ((status & DS2482_STATUS_TSB) == DS2482_STATUS_TSB);
search_direction =
((status & DS2482_STATUS_DIR) == DS2482_STATUS_DIR) ? (unsigned char) 1 : (unsigned char) 0;
// check for no devices on 1-Wire
if ((id_bit) && (cmp_id_bit))
break;
else
{
if ((!id_bit) && (!cmp_id_bit) && (search_direction == 0))
{
last_zero = id_bit_number;
// check for Last discrepancy in family
if (last_zero < 9)
LastFamilyDiscrepancy = last_zero;
}
// set or clear the bit in the ROM byte rom_byte_number
// with mask rom_byte_mask
if (search_direction == 1)
ROM_NO[rom_byte_number] |= rom_byte_mask;
else
ROM_NO[rom_byte_number] &= (unsigned char) ~rom_byte_mask;
// increment the byte counter id_bit_number
// and shift the mask rom_byte_mask
id_bit_number++;
rom_byte_mask <<= 1;
// if the mask is 0 then go to new SerialNum byte rom_byte_number
// and reset mask
if (rom_byte_mask == 0)
{
rom_byte_number++;
rom_byte_mask = 1;
}
}
}
while (rom_byte_number < 8); // loop until through all ROM bytes 0-7
// if the search was successful then
if (!(id_bit_number < 65))
{
// search successful so set LastDiscrepancy,LastDeviceFlag
// search_result
LastDiscrepancy = last_zero;
// check for last device
if (LastDiscrepancy == 0)
LastDeviceFlag = true;
search_result = true;
}
}
// if no device found then reset counters so next
// 'search' will be like a first
if (!search_result || (ROM_NO[0] == 0))
{
LastDiscrepancy = 0;
LastDeviceFlag = false;
LastFamilyDiscrepancy = 0;
search_result = false;
}
return search_result;
}