//--------------------------------------------------------------------------
// Send 1 bit of communication to the 1-Wire Net and verify that the
// response matches the 'applyPowerResponse' bit and apply power delivery
// to the 1-Wire net. Note that some implementations may apply the power
// first and then turn it off if the response is incorrect.
//
// 'portnum' - number 0 to MAX_PORTNUM-1. This number was provided to
// OpenCOM to indicate the port number.
// 'applyPowerResponse' - 1 bit response to check, if correct then start
// power delivery
//
// Returns: TRUE: bit written and response correct, strong pullup now on
// FALSE: response incorrect
//
SMALLINT owReadBitPower(int portnum, SMALLINT applyPowerResponse)
{
if(owTouchBit(portnum,0x01) != applyPowerResponse)
return FALSE;
if(owLevel(portnum,MODE_STRONG5) != MODE_STRONG5)
return FALSE;
return TRUE;
}
//--------------------------------------------------------------------------
// Send 8 bits of communication to the 1-Wire Net and return the
// result 8 bits read from the 1-Wire Net. The parameter 'sendbyte'
// least significant 8 bits are used and the least significant 8 bits
// of the result is the return byte.
//
// 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
// indicate the symbolic port number.
// 'sendbyte' - 8 bits to send (least significant byte)
//
// Returns: 8 bytes read from sendbyte
//
SMALLINT owTouchByte(int portnum, SMALLINT sendbyte)
{
int i;
SMALLINT dat = 0;
for (i=0; i<8; i++)
{
dat |= owTouchBit(portnum,sendbyte & 0x1) << i;
sendbyte >>= 1;
}
return dat;
}
//--------------------------------------------------------------------------
// Send 8 bits of communication to the 1-Wire Net and return the
// result 8 bits read from the 1-Wire Net. The parameter 'sendbyte'
// least significant 8 bits are used and the least significant 8 bits
// of the result is the return byte.
//
// 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
// indicate the symbolic port number.
// 'sendbyte' - 8 bits to send (least significant byte)
//
// Returns: 8 bytes read from sendbyte
//
SMALLINT owTouchByte(int portnum, SMALLINT sendbyte)
{
int i;
unsigned result = 0u;
for (i = 0; i < 8; i++){
if (owTouchBit(portnum,sendbyte & 1) != 0)
result |= (1u << i);
sendbyte >>= 1;
}
return (SMALLINT)result;
}
//--------------------------------------------------------------------------
// The 'owNext' function does a general search. This function
// continues from the previos search state. The search state
// can be reset by using the 'owFirst' function.
// This function contains one parameter 'alarm_only'.
// When 'alarm_only' is TRUE (1) the find alarm command
// 0xEC is sent instead of the normal search command 0xF0.
// Using the find alarm command 0xEC will limit the search to only
// 1-Wire devices that are in an 'alarm' state.
//
// 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
// indicate the symbolic port number.
// 'do_reset' - TRUE (1) perform reset before search, FALSE (0) do not
// perform reset before search.
// 'alarm_only' - TRUE (1) the find alarm command 0xEC is
// sent instead of the normal search command 0xF0
//
// Returns: TRUE (1) : when a 1-Wire device was found and it's
// Serial Number placed in the global SerialNum[portnum]
// FALSE (0): when no new device was found. Either the
// last search was the last device or there
// are no devices on the 1-Wire Net.
//
SMALLINT owNext(int portnum, SMALLINT do_reset, SMALLINT alarm_only)
{
uchar bit_test, search_direction, bit_number;
uchar last_zero, serial_byte_number, next_result;
uchar serial_byte_mask;
uchar lastcrc8;
// initialize for search
bit_number = 1;
last_zero = 0;
serial_byte_number = 0;
serial_byte_mask = 1;
next_result = 0;
setcrc8(portnum,0);
// if the last call was not the last one
if (!LastDevice[portnum])
{
// check if reset first is requested
if (do_reset)
{
// reset the 1-wire
// if there are no parts on 1-wire, return FALSE
if (!owTouchReset(portnum))
{
// printf("owTouchReset failed\r\n");
// reset the search
LastDiscrepancy[portnum] = 0;
LastFamilyDiscrepancy[portnum] = 0;
OWERROR(OWERROR_NO_DEVICES_ON_NET);
return FALSE;
}
}
// If finding alarming devices issue a different command
if (alarm_only)
owWriteByte(portnum,0xEC); // issue the alarming search command
else
owWriteByte(portnum,0xF0); // issue the search command
//pause before beginning the search
//usDelay(100);
// loop to do the search
do
{
// read a bit and its compliment
bit_test = owTouchBit(portnum,1) << 1;
bit_test |= owTouchBit(portnum,1);
// check for no devices on 1-wire
if (bit_test == 3)
break;
else
{
// all devices coupled have 0 or 1
if (bit_test > 0)
search_direction = !(bit_test & 0x01); // 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 (bit_number < LastDiscrepancy[portnum])
search_direction = ((SerialNum[portnum][serial_byte_number] & serial_byte_mask) > 0);
else
// if equal to last pick 1, if not then pick 0
search_direction = (bit_number == LastDiscrepancy[portnum]);
// if 0 was picked then record its position in LastZero
if (search_direction == 0)
{
last_zero = bit_number;
// check for Last discrepancy in family
if (last_zero < 9)
LastFamilyDiscrepancy[portnum] = last_zero;
}
}
// set or clear the bit in the SerialNum[portnum] byte serial_byte_number
// with mask serial_byte_mask
if (search_direction == 1)
SerialNum[portnum][serial_byte_number] |= serial_byte_mask;
else
SerialNum[portnum][serial_byte_number] &= ~serial_byte_mask;
// serial number search direction write bit
owTouchBit(portnum,search_direction);
// increment the byte counter bit_number
// and shift the mask serial_byte_mask
bit_number++;
serial_byte_mask <<= 1;
// if the mask is 0 then go to new SerialNum[portnum] byte serial_byte_number
// and reset mask
if (serial_byte_mask == 0)
{
// The below has been added to accomidate the valid CRC with the
// possible changing serial number values of the DS28E04.
if (((SerialNum[portnum][0] & 0x7F) == 0x1C) && (serial_byte_number == 1))
lastcrc8 = docrc8(portnum,0x7F);
else
lastcrc8 = docrc8(portnum,SerialNum[portnum][serial_byte_number]); // accumulate the CRC
serial_byte_number++;
serial_byte_mask = 1;
}
}
}
while(serial_byte_number < 8); // loop until through all SerialNum[portnum] bytes 0-7
// if the search was successful then
if (!((bit_number < 65) || lastcrc8))
{
// search successful so set LastDiscrepancy[portnum],LastDevice[portnum],next_result
LastDiscrepancy[portnum] = last_zero;
LastDevice[portnum] = (LastDiscrepancy[portnum] == 0);
next_result = TRUE;
}
}
// if no device found then reset counters so next 'next' will be
// like a first
if (!next_result || !SerialNum[portnum][0])
{
LastDiscrepancy[portnum] = 0;
LastDevice[portnum] = FALSE;
LastFamilyDiscrepancy[portnum] = 0;
next_result = FALSE;
}
return next_result;
}
//--------------------------------------------------------------------------
// The 'owNext' function does a general search. This function
// continues from the previos search state. The search state
// can be reset by using the 'owFirst' function.
// This function contains one parameter 'alarm_only'.
// When 'alarm_only' is TRUE (1) the find alarm command
// 0xEC is sent instead of the normal search command 0xF0.
// Using the find alarm command 0xEC will limit the search to only
// 1-Wire devices that are in an 'alarm' state.
//
// 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
// indicate the symbolic port number.
// 'do_reset' - TRUE (1) perform reset before search, FALSE (0) do not
// perform reset before search.
// 'alarm_only' - TRUE (1) the find alarm command 0xEC is
// sent instead of the normal search command 0xF0
//
// Returns: TRUE (1) : when a 1-Wire device was found and it's
// Serial Number placed in the global SerialNum[portnum]
// FALSE (0): when no new device was found. Either the
// last search was the last device or there
// are no devices on the 1-Wire Net.
//
BYTE owNext(BYTE portnum, BYTE do_reset, BYTE alarm_only)
{
BYTE bit_test, search_direction, bit_number;
BYTE last_zero, serial_byte_number, next_result;
BYTE serial_byte_mask;
BYTE lastcrc8;
owSetCurrentPort(portnum);
// initialize for search
bit_number = 1;
last_zero = 0;
serial_byte_number = 0;
serial_byte_mask = 1;
next_result = 0;
setcrc8(portnum, 0);
// if the last call was not the last one
if(!owNetCurrent.LastDevice) {
// check if reset first is requested
if(do_reset) {
// reset the 1-wire
// if there are no parts on 1-wire, return FALSE
if(!owTouchReset(owCurrentPortnum)) {
// reset the search
owNetCurrent.LastDiscrepancy = 0;
owNetCurrent.LastFamilyDiscrepancy = 0;
OWERROR(OWERROR_NO_DEVICES_ON_NET);
return FALSE;
}
}
// If finding alarming devices issue a different command
if(alarm_only) {
owWriteByte(owCurrentPortnum, 0xEC); // issue the alarming search command
} else {
owWriteByte(owCurrentPortnum, 0xF0); // issue the search command
}
//pause before beginning the search
//usDelay(100);
// loop to do the search
do {
// read a bit and its compliment
bit_test = owTouchBit(owCurrentPortnum, 1) << 1;
bit_test |= owTouchBit(owCurrentPortnum, 1);
// check for no devices on 1-wire
if(bit_test == 3) {
break;
}
// all devices coupled have 0 or 1
if(bit_test > 0) {
search_direction = !(bit_test & 0x01); // 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(bit_number < owNetCurrent.LastDiscrepancy) {
search_direction = ((owNetCurrent.SerialNum[serial_byte_number] & serial_byte_mask) > 0);
} else {
// if equal to last pick 1, if not then pick 0
search_direction = (bit_number == owNetCurrent.LastDiscrepancy);
}
// if 0 was picked then record its position in LastZero
if(search_direction == 0) {
last_zero = bit_number;
// check for Last discrepancy in family
if(last_zero < 9) {
owNetCurrent.LastFamilyDiscrepancy = last_zero;
}
}
}
// set or clear the bit in the SerialNum byte serial_byte_number
// with mask serial_byte_mask
if(search_direction == 1) {
owNetCurrent.SerialNum[serial_byte_number] |= serial_byte_mask;
} else {
owNetCurrent.SerialNum[serial_byte_number] &= ~serial_byte_mask;
}
// serial number search direction write bit
owTouchBit(owCurrentPortnum, search_direction);
// increment the byte counter bit_number
// and shift the mask serial_byte_mask
bit_number++;
serial_byte_mask <<= 1;
// if the mask is 0 then go to new SerialNum byte serial_byte_number
// and reset mask
if(serial_byte_mask == 0) {
lastcrc8 = docrc8(owCurrentPortnum, owNetCurrent.SerialNum[serial_byte_number]); // accumulate the CRC
serial_byte_number++;
serial_byte_mask = 1;
}
} while(serial_byte_number < 8); // loop until through all SerialNum bytes 0-7
// if the search was successful then
if(!((bit_number < 65) || lastcrc8)) {
// search successful so set LastDiscrepancy, LastDevice, next_result
owNetCurrent.LastDiscrepancy = last_zero;
if(last_zero == 0) {
owNetCurrent.LastDevice = TRUE;
} else {
owNetCurrent.LastDevice = FALSE;
}
// owNetCurrent.LastDevice = (last_zero == 0);
next_result = TRUE;
}
}
// if no device found then reset counters so next 'next' will be
// like a first
if(!next_result || !owNetCurrent.SerialNum[0]) {
owNetCurrent.LastDiscrepancy = 0;
owNetCurrent.LastDevice = FALSE;
owNetCurrent.LastFamilyDiscrepancy = 0;
next_result = FALSE;
}
return next_result;
}
