int Temp_DoRead(int iSensor)
{
uchar send_block[30], lastcrc8;
int send_cnt, tsht = 0, i, loop = 0;
// LED_Set(6);
if(iSensor >= NumDevices)
return 0;
// LED_Set(7);
owSerialNum(PORTNUM, TempSensorSN[iSensor], FALSE);
for (loop = 0; loop < 2; loop++) {
// access the device
if (owAccess(PORTNUM)) {
// send the convert command and if nesessary start power delivery
if (!owWriteByte(PORTNUM, 0x44))
return 0;
// access the device
if (owAccess(PORTNUM)) {
// create a block to send that reads the temperature
// read scratchpad command
send_cnt = 0;
send_block[send_cnt++] = 0xBE;
// now add the read bytes for data bytes and crc8
for (i = 0; i < 9; i++)
send_block[send_cnt++] = 0xFF;
// now send the block
if (owBlock(PORTNUM, FALSE, send_block, send_cnt)) {
// initialize the CRC8
setcrc8(PORTNUM, 0);
// perform the CRC8 on the last 8 bytes of packet
for (i = send_cnt - 9; i < send_cnt; i++)
lastcrc8 = docrc8(PORTNUM, send_block[i]);
// verify CRC8 is correct
if (lastcrc8 == 0x00) {
// calculate the high-res temperature
tsht = send_block[2] << 8;
tsht = tsht | send_block[1];
if (tsht & 0x00001000)
tsht = tsht | 0xffff0000;
if(!(tsht == 1360 && LastTemperature[iSensor] == 0)){
LastTemperature[iSensor] = tsht;
}else{
tsht = 0;
}
// success
break;
}
}
}
}
}
return tsht;
}
/* -----------------------------------------------------------------------
----------------------------------------------------------------------- */
int get_ibl_type(int portnum, uchar page, int offset)
{
uchar send_block[50];
int send_cnt=0;
int i;
ushort lastcrc8=255;
/* 01/08/2004 [bcl] DigiTemp does this before calling the function
* owSerialNum(portnum,SNum,FALSE);
*/
// Recall the Status/Configuration page
// Recall command
send_block[send_cnt++] = 0xB8;
// Page to Recall
send_block[send_cnt++] = page;
if(!owBlock(portnum,FALSE,send_block,send_cnt))
return FALSE;
send_cnt = 0;
if(owAccess(portnum))
{
// Read the Status/Configuration byte
// Read scratchpad command
send_block[send_cnt++] = 0xBE;
// Page for the Status/Configuration byte
send_block[send_cnt++] = page;
for(i=0;i<9;i++)
send_block[send_cnt++] = 0xFF;
if(owBlock(portnum,FALSE,send_block,send_cnt))
{
setcrc8(portnum,0);
for(i=2;i<send_cnt;i++)
lastcrc8 = docrc8(portnum,send_block[i]);
if(lastcrc8 != 0x00)
return FALSE;
} else {
return FALSE;
}
// Return the requested byte
return send_block[2+offset];
}//Access
return -1;
}
/*
ds2338mem_rd
Reading DS2438 memory
returns one page of memory
input parameters
portnum the port number of the port being used for the
1-Wire Network.
SNum the serial number for the part that the read is
to be done on.
pageno the page number of memory to be read
*/
int
ds2438mem_rd(int portnum, uchar *SNum, uchar *pagemem, uchar pageno, char *device) {
int block_cnt;
int i;
ushort lastcrc8;
owSerialNum(portnum,SNum,FALSE);
block_cnt = 0;
// Recall the Status/Configuration page
// Recall command
pagemem[block_cnt++] = 0xB8;
// Page to Recall
pagemem[block_cnt++] = pageno;
owAccess(portnum);
owBlock(portnum,FALSE,pagemem,block_cnt);
syslog(LOG_DEBUG, "ds2438mem_rd: recall memory (B8h %xh): %s\n",
pageno, ppagemem(pagemem));
block_cnt = 0;
// Read the Status/Configuration byte
// Read scratchpad command
pagemem[block_cnt++] = 0xBE;
// Page for the Status/Configuration byte
pagemem[block_cnt++] = pageno;
for(i=0;i<9;i++)
pagemem[block_cnt++] = 0xFF;
owAccess(portnum);
owBlock(portnum,FALSE,pagemem,block_cnt);
syslog(LOG_DEBUG,"ds2438mem_rd: read scratchpad (BEh %xh): %s \n",
pageno, ppagemem( pagemem));
setcrc8(portnum,0);
for(i=2;i<block_cnt;i++) {
lastcrc8 = docrc8(portnum,pagemem[i]);
}
if(lastcrc8 != 0x00) {
syslog(LOG_ALERT, "ds2438mem_rd: CRC error ");
bitprint( lastcrc8, "lastcrc8");
return 1;
}
return 0;
}
//----------------------------------------------------------------------
// Read the temperature of a DS1920/DS1820
//
// 'portnum' - number 0 to MAX_PORTNUM-1. This number was provided to
// OpenCOM to indicate the port number.
// 'SerialNum' - Serial Number of DS1920/DS1820 to read temperature from
// 'Temp ' - pointer to variable where that temperature will be
// returned
//
// Returns: TRUE(1) temperature has been read and verified
// FALSE(0) could not read the temperature, perhaps device is not
// in contact
//
int ReadTemperature(int portnum, uchar *SerialNum, float *Temp)
{
int rt=FALSE;
uchar send_block[30],lastcrc8;
int send_cnt=0, tsht, i, loop=0;
float tmp,cr,cpc;
setcrc8(portnum,0);
// set the device serial number to the counter device
owSerialNum(portnum,SerialNum,FALSE);
for (loop = 0; rt==FALSE && loop < 2; loop ++)
{
// access the device
if (owAccess(portnum))
{
// send the convert temperature command
owTouchByte(portnum,0x44);
// set the 1-Wire Net to strong pull-up
if (owLevel(portnum,MODE_STRONG5) != MODE_STRONG5)
return FALSE;
// sleep for 1 second
msDelay(1000);
// turn off the 1-Wire Net strong pull-up
if (owLevel(portnum,MODE_NORMAL) != MODE_NORMAL)
return FALSE;
// access the device
if (owAccess(portnum))
{
// create a block to send that reads the temperature
// read scratchpad command
send_block[send_cnt++] = 0xBE;
// now add the read bytes for data bytes and crc8
for (i = 0; i < 9; i++)
send_block[send_cnt++] = 0xFF;
// now send the block
if (owBlock(portnum,FALSE,send_block,send_cnt))
{
// perform the CRC8 on the last 8 bytes of packet
for (i = send_cnt - 9; i < send_cnt; i++)
lastcrc8 = docrc8(portnum,send_block[i]);
// verify CRC8 is correct
if (lastcrc8 == 0x00)
{
// calculate the high-res temperature
tsht = send_block[1]/2;
if (send_block[2] & 0x01)
tsht |= -128;
tmp = (float)(tsht);
cr = send_block[7];
cpc = send_block[8];
if (((cpc - cr) == 1) && (loop == 0))
continue;
if (cpc == 0)
return FALSE;
else
tmp = tmp - (float)0.25 + (cpc - cr)/cpc;
*Temp = tmp;
// success
rt = TRUE;
}
}
}
}
}
// return the result flag rt
return rt;
}
//--------------------------------------------------------------------------
//! Perform the 1-Wire Search Algorithm on the 1-Wire bus using the existing
//! search state.
//! @return TRUE : device found, ROM number in ROM_NO buffer
//! FALSE : device not found, end of search
//
int OWSearch()
{
int id_bit_number;
int last_zero, rom_byte_number, search_result;
int id_bit, cmp_id_bit;
uchar 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;
crc8 = 0;
// if the last call was not the last one
if (!LastDeviceFlag)
{
// 1-Wire reset
if (!OWReset())
{
// reset the search
LastDiscrepancy = 0;
LastDeviceFlag = FALSE;
LastFamilyDiscrepancy = 0;
return FALSE;
}
// issue the search command
OWWriteByte(0xF0);
// loop to do the search
do
{
// read a bit and its complement
id_bit = OWReadBit();
cmp_id_bit = OWReadBit();
// 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
if (id_bit_number == LastDiscrepancy)
search_direction = 1;
else
search_direction = 0;
// 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] &= ~rom_byte_mask;
// serial number search direction write bit
OWWriteBit(search_direction);
// 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)
{
docrc8(ROM_NO[rom_byte_number]); // accumulate the CRC
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) || (crc8 != 0)))
{
// 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;
}
return search_result;
}
/*
SetupVsens
setup DS2438 to read Vsens voltage difference
enable IAD, CA and EE of status configuration register ( page <0h> byte <0h>)
Vsens A/D conversion occurs with a frequency of 36.41 measurements/sec
once IAD is enabled ( set to '1'). No special command necessary.
input parameters
portnum port number
SNum serial number of DS2438
device device (USB DS2490 or serial DS9097U)
*/
int SetupVsens(int portnum, uchar *SNum, char *device)
{
uchar datablock[50];
uchar conf_reg = 0x00;
int send_cnt = 0;
int i;
ushort lastcrc8;
int busybyte;
double ti, tf;
struct timezone tz;
struct timeval tv;
gettimeofday( &tv, &tz);
ti = tv.tv_sec+1.0e-6*tv.tv_usec;
/* enable IAD, CA and EE of configuration byte */
conf_reg |= IAD | CA | EE;
owSerialNum(portnum,SNum,FALSE);
// Recall the Status/Configuration page
// Recall command
datablock[send_cnt++] = 0xB8;
// Page to Recall
datablock[send_cnt++] = 0x00;
if(!owBlock(portnum,FALSE,datablock,send_cnt))
return FALSE;
send_cnt = 0;
if(owAccess(portnum))
{
// Read the Status/Configuration byte
// Read scratchpad command
datablock[send_cnt++] = 0xBE;
// Page for the Status/Configuration byte
datablock[send_cnt++] = 0x00;
for(i=0;i<9;i++)
datablock[send_cnt++] = 0xFF;
if(owBlock(portnum,FALSE,datablock,send_cnt))
{
setcrc8(portnum,0);
for(i=2;i<send_cnt;i++)
lastcrc8 = docrc8(portnum,datablock[i]);
if(lastcrc8 != 0x00)
return FALSE;
}//Block
else
return FALSE;
if ( datablock[2] & conf_reg ) {
syslog(LOG_DEBUG, "SetupVsens: IAD, CA and EE are set: return!\n");
gettimeofday( &tv, &tz);
tf = tv.tv_sec+1.0e-6*tv.tv_usec;
syslog(LOG_DEBUG,
"SetupVsens: elapsed time: %f\n", tf -ti);
return TRUE;
} else {
syslog(LOG_DEBUG,
"SetupVsens: IAD, CA and EE are not set. Continue to setup\n");
}
}//Access
if(owAccess(portnum))
{
send_cnt = 0;
// Write the Status/Configuration byte
// Write scratchpad command
datablock[send_cnt++] = 0x4E;
// Write page
datablock[send_cnt++] = 0x00;
// IAD, CA and EE set to "1"
datablock[send_cnt++] |= conf_reg;
// do not change the rest
for(i=0;i<7;i++)
datablock[send_cnt++] = datablock[i+3];
if(owBlock(portnum,FALSE,datablock,send_cnt))
{
send_cnt = 0;
if(owAccess(portnum))
{
// Copy the Status/Configuration byte
// Copy scratchpad command
datablock[send_cnt++] = 0x48;
// Copy page
datablock[send_cnt++] = 0x00;
if(owBlock(portnum,FALSE,datablock,send_cnt))
{
busybyte = owReadByte(portnum);
while(busybyte == 0)
busybyte = owReadByte(portnum);
gettimeofday( &tv, &tz);
tf = tv.tv_sec+1.0e-6*tv.tv_usec;
syslog(LOG_DEBUG,
"SetupVsens: elapsed time: %f\n", tf -ti);
return TRUE;
}//Block
}//Access
}//Block
}//Access
return FALSE;
}
//----------------------------------------------------------------------
// Family 0x10 Demo
//
void main(void)
{
int temp;
int sign;
BYTE i;
//----------------------------------------
ADCON1 = 0x07; // PortB digital
bTRD6 = 1; // RD6 = Serial Input
bTRD7 = 0; // RD7 = Serial Output
bLD7 = 1;
printf("\nFamily 0x10 Demo\n%");
////////////////////////////////////////////////////////////
// Initialise the OneWire network (bus)
// attempt to acquire the 1-Wire Nets
if (!owAcquire(0, NULL)) {
printf("Acquire failed.\n%");
while(1)
;
}
////////////////////////////////////////////////////////////
// Let's set the alarmtemps of all devices on the bus.
// To demonstrate this, we write a low alarmtemp of 19
// and a high alarmtemp of 21 to all devices.
// Finally we copy the alarmtemps to non-volatile EEPROM.
printf("\nStart - Set AlarmTemperatures.\n%");
// Reset the devices
owTouchReset(0);
// Address all devices on the net
owWriteByte(0, OW_SKIPROM);
// Use the WriteScratchpad command to set AlarmTemps
owWriteByte(0, OW_WRITESCRATCHPAD);
owWriteByte(0, 19); // Valid RoomTemperature
owWriteByte(0, 21); // 19 <= Temp < 21
printf("End - Set AlarmTemperatures.\n%");
// Set alarmtemps done
// Copy the temps to EEPROM
printf("\nStart - Write AlarmTemperatures to EEPROM.\n%");
// Reset the devices
owTouchReset(0);
// Address all devices on the net
owWriteByte(0, OW_SKIPROM);
// send the CopyScratchpad command to copy the AlarmTemps to EEPROM
// If the bus supports Strong PullUp, we use it (because
// there might be parasite powered devices on this bus).
if(owHasPowerDelivery(0)) {
printf("The bus has a Strong PullUp\n%");
owWriteBytePower(0, OW_COPYSCRATCHPAD);
// Eeprom update takes 10 milliseconds max. 11ms is safer
Wait(11);
// turn off the strong pull-up
owLevel(0, MODE_NORMAL);
} else {
printf("The bus has NO Strong PullUp\n%");
owWriteByte(0, OW_COPYSCRATCHPAD);
// Eeprom update takes 10 milliseconds max. 11ms is safer
Wait(11);
}
printf("End - Write AlarmTemperatures to EEPROM.\n%");
// Copy the temps to EEPROM done
while(1) {
////////////////////////////////////////////////////////////
// We do a temp conversion on all DS18S20's
printf("\nStart - TemperatureConversions\n%");
// Reset the devices
owTouchReset(0);
// Address all devices on this net
owWriteByte(0, OW_SKIPROM);
// Send the convert command and start power delivery if available.
// Note that we use a different way here to determine
// Strong PullUp capability.
if(owWriteBytePower(0, OW_CONVERTT)) {
printf("We are using a Strong PullUp.\n%");
} else {
printf("No Strong PullUp configured.\n%");
owWriteByte(0, OW_CONVERTT);
}
// Coversion takes 750 milliseconds max. 751ms is safer
Wait(751);
// turn off the 1-Wire Net strong pull-up
owLevel(0, MODE_NORMAL);
printf("End - TemperatureConversions\n%");
////////////////////////////////////////////////////////////
// We will now demonstrate an alarmsearch
printf("\nStart - Find devices in alarmstate\n%");
// Find the devices with temp < 19 or temp >= 21
if(!owFirst(0, TRUE, TRUE)) {
printf("No devices in AlarmState found.\n%");
} else {
do {
printf("Device in AlarmState found: 0x%02X%02X%02X%02X%02X%02X%02X%02X\n%",
owNetCurrent.SerialNum[7],
owNetCurrent.SerialNum[6],
owNetCurrent.SerialNum[5],
owNetCurrent.SerialNum[4],
owNetCurrent.SerialNum[3],
owNetCurrent.SerialNum[2],
owNetCurrent.SerialNum[1],
owNetCurrent.SerialNum[0]);
} while(owNext(0, TRUE, TRUE));
}
printf("End - Find devices in alarmstate\n%");
////////////////////////////////////////////////////////////
// We will now demonstrate a normal search. For
// every device found, it's temperature is retrieved.
printf("\nStart - Find devices and get their temperatures.\n%");
if(!owFirst(0, TRUE, FALSE)) {
printf("No devices found.\n%");
} else {
do {
printf("Device found: 0x%02X%02X%02X%02X%02X%02X%02X%02X%",
owNetCurrent.SerialNum[7],
owNetCurrent.SerialNum[6],
owNetCurrent.SerialNum[5],
owNetCurrent.SerialNum[4],
owNetCurrent.SerialNum[3],
owNetCurrent.SerialNum[2],
owNetCurrent.SerialNum[1],
owNetCurrent.SerialNum[0]);
// Init the crc
setcrc8(0, 0);
// Read the device's memory
owWriteByte(0, OW_READSCRATCHPAD);
for(i = 0; i < SCRATCHPAD_SIZE; i++) {
ScratchPad[i] = owReadByte(0);
docrc8(0, ScratchPad[i]);
}
// Check the CRC
if(owNetCurrent.utilcrc8 != 0) {
printf(", crc is NOT OK.\n%");
} else {
// We don't want to use float's
temp = ((int)ScratchPad[SCRATCHPAD_TEMPERATUREMSB] << 8) |
(int)ScratchPad[SCRATCHPAD_TEMPERATURELSB];
if(temp < 0) {
temp = -temp;
sign = '-';
} else if(temp == 0) {
sign = ' ';
} else {
sign = '+';
}
printf(", Temperature is %c%d.%d degrees\n%",
sign,
(temp >> 1),
(temp & 0x01) ? 5 : 0);
}
} while(owNext(0, TRUE, FALSE));
}
printf("End - Find devices and get their temperatures.\n%");
////////////////////////////////////////////////////////////
Wait(1); // Just a convenient way to set a breakpoint
}
}
/* MAXIM App. Note #187 */
static int ds24xx_search_rom()
{
int id_bit_number;
int last_zero, rom_byte_number, search_result;
int id_bit, cmp_id_bit;
unsigned char rom_byte_mask, search_direction;
unsigned char crc8 = 0;
/* 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 (!ds24xx_reset()) {
/* reset the search*/
dbg_info("1-Wire: reset fail\n");
LastDiscrepancy = 0;
LastDeviceFlag = 0;
LastFamilyDiscrepancy = 0;
return 0;
}
/* issue the search command */
ds24xx_write_byte(ROM_COMMAND_SEARCH);
/* loop to do the search */
do
{
/* read a bit and its complement */
id_bit = ds24xx_read_bit();
cmp_id_bit = ds24xx_read_bit();
/* 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;
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 =
((buf[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)
buf[rom_byte_number] |= rom_byte_mask;
else
buf[rom_byte_number] &= ~rom_byte_mask;
/* serial number search direction write bit */
if (search_direction == 1)
ds24xx_write_bit(1);
else
ds24xx_write_bit(0);
/*
* 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) {
crc8 = docrc8(crc8,
buf[rom_byte_number]);
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) || (crc8 != 0))) {
/* search successful so set LastDiscrepancy,LastDeviceFlag,search_result */
LastDiscrepancy = last_zero;
/* check for last device */
if (LastDiscrepancy == 0)
LastDeviceFlag = 1;
search_result = 1;
}
}
/* if no device found then reset counters so next 'search' will be like a first */
if (!search_result || !buf[0]) {
LastDiscrepancy = 0;
LastDeviceFlag = 0;
LastFamilyDiscrepancy = 0;
search_result = 0;
}
return search_result;
}
//----------------------------------------------------------------------
// Read the temperature of a DS18B20 (family code 0x28)
//
// 'portnum' - number 0 to MAX_PORTNUM-1. This number was provided to
// OpenCOM to indicate the port number.
// 'SerialNum' - Serial Number of DS18B20 to read temperature from
// 'Temp ' - pointer to variable where that temperature will be
// returned
//
// Returns: TRUE(1) temperature has been read and verified
// FALSE(0) could not read the temperature, perhaps device is not
// in contact
//
int ReadTemperature28(int portnum, uchar *SerialNum, float *Temp)
{
uchar rt=FALSE;
uchar send_block[30],lastcrc8;
int send_cnt, tsht, i, loop=0;
int power;
// set the device serial number to the counter device
owSerialNum(portnum,SerialNum,FALSE);
for (loop = 0; loop < 2; loop ++)
{
// check if the chip is connected to VDD
if (owAccess(portnum))
{
owWriteByte(portnum,0xB4);
power = owReadByte(portnum);
}
// access the device
if (owAccess(portnum))
{
// send the convert command and if nesessary start power delivery
if (power) {
if (!owWriteBytePower(portnum,0x44))
return FALSE;
} else {
if (!owWriteByte(portnum,0x44))
return FALSE;
}
// sleep for 1 second
msDelay(1000);
// turn off the 1-Wire Net strong pull-up
if (power) {
if (owLevel(portnum,MODE_NORMAL) != MODE_NORMAL)
return FALSE;
}
// access the device
if (owAccess(portnum))
{
// create a block to send that reads the temperature
// read scratchpad command
send_cnt = 0;
send_block[send_cnt++] = 0xBE;
// now add the read bytes for data bytes and crc8
for (i = 0; i < 9; i++)
send_block[send_cnt++] = 0xFF;
// now send the block
if (owBlock(portnum,FALSE,send_block,send_cnt))
{
// initialize the CRC8
setcrc8(portnum,0);
// perform the CRC8 on the last 8 bytes of packet
for (i = send_cnt - 9; i < send_cnt; i++)
lastcrc8 = docrc8(portnum,send_block[i]);
// verify CRC8 is correct
if (lastcrc8 == 0x00)
{
// calculate the high-res temperature
tsht = send_block[2] << 8;
tsht = tsht | send_block[1];
if (tsht & 0x00001000)
tsht = tsht | 0xffff0000;
*Temp = ((float) tsht)/16;
// success
rt = TRUE;
break;
}
}
}
}
}
// return the result flag rt
return rt;
}
//----------------------------------------------------------------------
// Read the temperature of a DS18B20
//
// 'portnum' - number 0 to MAX_PORTNUM-1. This number was provided to
// OpenCOM to indicate the port number.
// 'SerialNum' - Serial Number of DS1920/DS1820 to read temperature from
// 'Temp ' - pointer to variable where that temperature will be
// returned
//
// Returns: TRUE(1) temperature has been read and verified
// FALSE(0) could not read the temperature, perhaps device is not
// in contact
//
int ReadTemperature28(int portnum, uchar *SerialNum, float *Temp)
{
uchar rt=FALSE;
uchar send_block[30],lastcrc8;
int send_cnt, tsht, i, loop=0;
float tmp,cr,cpc;
// set the device serial number to the counter device
owSerialNum(portnum,SerialNum,FALSE);
for (loop = 0; loop < 2; loop ++)
{
// access the device
if (owAccess(portnum))
{
// send the convert command and start power delivery
if (!owWriteBytePower(portnum,0x44))
return FALSE;
// sleep for 1 second
msDelay(1000);
// turn off the 1-Wire Net strong pull-up
if (owLevel(portnum,MODE_NORMAL) != MODE_NORMAL)
return FALSE;
// access the device
if (owAccess(portnum))
{
// create a block to send that reads the temperature
// read scratchpad command
send_cnt = 0;
send_block[send_cnt++] = 0xBE;
// now add the read bytes for data bytes and crc8
for (i = 0; i < 9; i++)
send_block[send_cnt++] = 0xFF;
// now send the block
if (owBlock(portnum,FALSE,send_block,send_cnt))
{
// initialize the CRC8
setcrc8(portnum,0);
// perform the CRC8 on the last 8 bytes of packet
for (i = send_cnt - 9; i < send_cnt; i++)
lastcrc8 = docrc8(portnum,send_block[i]);
// verify CRC8 is correct
if (lastcrc8 == 0x00)
{
// calculate the high-res temperature
tsht = (send_block[1] >> 4) + ((send_block[2] & 0x07) << 4);
if (send_block[2] & 0x80)
tsht |= -128;
tmp = (float)(tsht);
//cr = send_block[7];
//cpc = send_block[8];
//if (((cpc - cr) == 1) && (loop == 0))
// continue;
//if (cpc == 0)
// return FALSE;
//else
// tmp = tmp - (float)0.25 + (cpc - cr)/cpc;
// TODO: Check config register
if(send_block[1] & 0x01) {
tmp += 0.0625f;
}
else if(send_block[1] & 0x02) {
tmp += 0.125f;
}
else if(send_block[1] & 0x04) {
tmp += 0.25f;
}
else if(send_block[1] & 0x08) {
tmp += 0.5f;
}
*Temp = tmp;
// success
rt = TRUE;
break;
}
}
}
}
}
//--------------------------------------------------------------------------
// The 'OWSearch' 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.
//
// Returns: TRUE (1) : when a 1-Wire device was found and it's
// Serial Number placed in the global ROM
// 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.
//
int DallasOneWire::OWSearch(void)
{
DATA(F("OWSearch"));
unsigned char last_zero,pos;
unsigned char tmp_rom[8];
unsigned char readbuffer[20],sendpacket[40];
unsigned char i,sendlen=0;
// if the last call was the last one
if (LastDeviceFlag)
{
DATA(F("OWSearch: the last call was the last one"));
// reset the search
LastDiscrepancy = 0;
LastDeviceFlag = FALSE;
LastFamilyDiscrepancy = 0;
return FALSE;
}
// reset the 1-wire
// if there are no parts on 1-wire, return FALSE
if (!OWReset())
{
DEBUG(F("OWSearch: there are no parts on 1-wire, return FALSE"));
// reset the search
LastDiscrepancy = 0;
LastFamilyDiscrepancy = 0;
return FALSE;
}
// build the command stream
// call a function that may add the change mode command to the buff
// check for correct mode
if (UMode != MODSEL_DATA)
{
DATA(F("OWSearch: UMode != MODSEL_DATA"));
UMode = MODSEL_DATA;
sendpacket[sendlen++] = MODE_DATA;
}
// search command
sendpacket[sendlen++] = 0xF0;
// change back to command mode
UMode = MODSEL_COMMAND;
sendpacket[sendlen++] = MODE_COMMAND;
// search mode on
sendpacket[sendlen++] = (unsigned char)(CMD_COMM | FUNCTSEL_SEARCHON | USpeed);
// change back to data mode
UMode = MODSEL_DATA;
sendpacket[sendlen++] = MODE_DATA;
// set the temp Last Discrepancy to 0
last_zero = 0;
// add the 16 bytes of the search
pos = sendlen;
for (i = 0; i < 16; i++)
sendpacket[sendlen++] = 0;
// only modify bits if not the first search
if (LastDiscrepancy != 0)
{
DATA(F("OWSearch: LastDiscrepancy != 0"));
// set the bits in the added buffer
for (i = 0; i < 64; i++)
{
// before last discrepancy
if (i < (LastDiscrepancy - 1))
bitacc(WRITE_FUNCTION,
bitacc(READ_FUNCTION,0,i,&ROM_NO[0]),
(short)(i * 2 + 1),
&sendpacket[pos]);
// at last discrepancy
else if (i == (LastDiscrepancy - 1))
bitacc(WRITE_FUNCTION,1,(short)(i * 2 + 1),
&sendpacket[pos]);
// after last discrepancy so leave zeros
}
}
// change back to command mode
UMode = MODSEL_COMMAND;
sendpacket[sendlen++] = MODE_COMMAND;
// search OFF command
sendpacket[sendlen++] = (unsigned char)(CMD_COMM | FUNCTSEL_SEARCHOFF | USpeed);
// flush the buffers
flush();
// send the packet
if (WriteCOM(sendlen,sendpacket))
{
// read back the 1 byte response
if (ReadCOM(17,readbuffer) == 17)
{
// interpret the bit stream
for (i = 0; i < 64; i++)
{
// get the ROM bit
bitacc(WRITE_FUNCTION,
bitacc(READ_FUNCTION,0,(short)(i * 2 + 1),&readbuffer[1]),i,
&tmp_rom[0]);
// check LastDiscrepancy
if ((bitacc(READ_FUNCTION,0,(short)(i * 2),&readbuffer[1]) == 1) &&
(bitacc(READ_FUNCTION,0,(short)(i * 2 + 1),&readbuffer[1]) == 0))
{
last_zero = i + 1;
// check LastFamilyDiscrepancy
if (i < 8)
LastFamilyDiscrepancy = i + 1;
}
}
// do dowcrc
crc8 = 0;
for (i = 0; i < 8; i++)
docrc8(tmp_rom[i]);
// check results
if ((crc8 != 0) || (LastDiscrepancy == 63) || (tmp_rom[0] == 0))
{
// error during search
// reset the search
LastDiscrepancy = 0;
LastDeviceFlag = FALSE;
LastFamilyDiscrepancy = 0;
return FALSE;
}
// successful search
else
{
// set the last discrepancy
LastDiscrepancy = last_zero;
// check for last device
if (LastDiscrepancy == 0)
LastDeviceFlag = TRUE;
// copy the ROM to the buffer
for (i = 0; i < 8; i++)
ROM_NO[i] = tmp_rom[i];
return TRUE;
}
}
}
WARNING(F("OWSearch: an error occured so re-sync with DS2480B"));
// an error occured so re-sync with DS2480B
DS2480B_Detect();
// reset the search
LastDiscrepancy = 0;
LastDeviceFlag = FALSE;
LastFamilyDiscrepancy = 0;
return FALSE;
}
//--------------------------------------------------------------------------
// 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;
}
int Ow_Search()
{
int id_bit_number;
int last_zero, rom_byte_number, search_result;
int 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;
crc8 = 0;
// if the last call was not the last one
if (!LastDeviceFlag)
{
// 1-Wire reset
if (Ow_Reset())
{
// reset the search
LastDiscrepancy = 0;
LastDeviceFlag = 0;
LastFamilyDiscrepancy = 0;
return 0;
}
// issue the search command
Ow_Write_Byte(0xF0);
// loop to do the search
do
{
// read a bit and its complement
id_bit = OW_Read_Bit();
cmp_id_bit = OW_Read_Bit();
// 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 is 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
//postavlja vrednost procitanog bita
if (search_direction == 1)
ROM_NO[rom_byte_number] |= rom_byte_mask;
else
ROM_NO[rom_byte_number] &= ~rom_byte_mask;
// serial number search direction write bit
if (search_direction)
Ow_Write_One();
else
Ow_Write_Zero();
// 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)
{
docrc8(ROM_NO[rom_byte_number]); // accumulate the CRC
rom_byte_number++;
rom_byte_mask = 1;
}
}
} // End of search loop
while(rom_byte_number < 8); // loop until through all ROM bytes 0-7
//IntToStr(id_bit_number,tmp);
//Lcd_Out(1,1,tmp);
// if the search was successful then
if (id_bit_number == 65)
{
// search successful so set LastDiscrepancy,LastDeviceFlag,search_result
LastDiscrepancy = last_zero;
//Lcd_Out(2,1,"mlp");
// check for last device
if (LastDiscrepancy == 0)
LastDeviceFlag = 1;
search_result = 1;
//IntToStr(search_result,tmp1);
//Lcd_Out(1,9,tmp1);
}
}
// if no device found then reset counters so next 'search' will be
// like a first
if (!search_result || !ROM_NO[0])
{
LastDiscrepancy = 0;
LastDeviceFlag = 0;
LastFamilyDiscrepancy = 0;
search_result = 0;
}
return search_result;
} // End of Ow-Search function
//--------------------------------------------------------------------------
// 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 was provided to
// OpenCOM to indicate the 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
// 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 last_zero,pos;
uchar tmp_serial_num[8];
uchar readbuffer[20],sendpacket[40];
uchar i,sendlen=0;
uchar lastcrc8;
// if the last call was the last one
if (LastDevice[portnum])
{
// reset the search
LastDiscrepancy[portnum] = 0;
LastDevice[portnum] = FALSE;
LastFamilyDiscrepancy[portnum] = 0;
return FALSE;
}
// 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))
{
// reset the search
LastDiscrepancy[portnum] = 0;
LastFamilyDiscrepancy[portnum] = 0;
OWERROR(OWERROR_NO_DEVICES_ON_NET);
return FALSE;
}
}
// build the command stream
// call a function that may add the change mode command to the buff
// check if correct mode
if (UMode[portnum] != MODSEL_DATA)
{
UMode[portnum] = MODSEL_DATA;
sendpacket[sendlen++] = MODE_DATA;
}
// search command
if (alarm_only)
sendpacket[sendlen++] = 0xEC; // issue the alarming search command
else
sendpacket[sendlen++] = 0xF0; // issue the search command
// change back to command mode
UMode[portnum] = MODSEL_COMMAND;
sendpacket[sendlen++] = MODE_COMMAND;
// search mode on
sendpacket[sendlen++] = (uchar)(CMD_COMM | FUNCTSEL_SEARCHON | USpeed[portnum]);
// change back to data mode
UMode[portnum] = MODSEL_DATA;
sendpacket[sendlen++] = MODE_DATA;
// set the temp Last Descrep to none
last_zero = 0;
// add the 16 bytes of the search
pos = sendlen;
for (i = 0; i < 16; i++)
sendpacket[sendlen++] = 0;
// only modify bits if not the first search
if (LastDiscrepancy[portnum] != 0)
{
// set the bits in the added buffer
for (i = 0; i < 64; i++)
{
// before last discrepancy
if (i < (LastDiscrepancy[portnum] - 1))
bitacc(WRITE_FUNCTION,
bitacc(READ_FUNCTION,0,i,&SerialNum[portnum][0]),
(short)(i * 2 + 1),
&sendpacket[pos]);
// at last discrepancy
else if (i == (LastDiscrepancy[portnum] - 1))
bitacc(WRITE_FUNCTION,1,
(short)(i * 2 + 1),
&sendpacket[pos]);
// after last discrepancy so leave zeros
}
}
// change back to command mode
UMode[portnum] = MODSEL_COMMAND;
sendpacket[sendlen++] = MODE_COMMAND;
// search OFF
sendpacket[sendlen++] = (uchar)(CMD_COMM | FUNCTSEL_SEARCHOFF | USpeed[portnum]);
// flush the buffers
FlushCOM(portnum);
// send the packet
if (WriteCOM(portnum,sendlen,sendpacket))
{
// read back the 1 byte response
if (ReadCOM(portnum,17,readbuffer) == 17)
{
// interpret the bit stream
for (i = 0; i < 64; i++)
{
// get the SerialNum bit
bitacc(WRITE_FUNCTION,
bitacc(READ_FUNCTION,0,(short)(i * 2 + 1),&readbuffer[1]),
i,
&tmp_serial_num[0]);
// check LastDiscrepancy
if ((bitacc(READ_FUNCTION,0,(short)(i * 2),&readbuffer[1]) == 1) &&
(bitacc(READ_FUNCTION,0,(short)(i * 2 + 1),&readbuffer[1]) == 0))
{
last_zero = i + 1;
// check LastFamilyDiscrepancy
if (i < 8)
LastFamilyDiscrepancy[portnum] = i + 1;
}
}
// do dowcrc
setcrc8(portnum,0);
// for (i = 0; i < 8; i++)
// lastcrc8 = docrc8(portnum,tmp_serial_num[i]);
// The above has been commented out for the DS28E04. The
// below has been added to accomidate the valid CRC with the
// possible changing serial number values of the DS28E04.
for (i = 0; i < 8; i++)
{
if (((tmp_serial_num[0] & 0x7F) == 0x1C) && (i == 1))
lastcrc8 = docrc8(portnum,0x7F);
else
lastcrc8 = docrc8(portnum,tmp_serial_num[i]);
}
// check results
if ((lastcrc8 != 0) || (LastDiscrepancy[portnum] == 63) || (tmp_serial_num[0] == 0))
{
// error during search
// reset the search
LastDiscrepancy[portnum] = 0;
LastDevice[portnum] = FALSE;
LastFamilyDiscrepancy[portnum] = 0;
OWERROR(OWERROR_SEARCH_ERROR);
return FALSE;
}
// successful search
else
{
// set the last discrepancy
LastDiscrepancy[portnum] = last_zero;
// check for last device
if (LastDiscrepancy[portnum] == 0)
LastDevice[portnum] = TRUE;
// copy the SerialNum to the buffer
for (i = 0; i < 8; i++)
SerialNum[portnum][i] = tmp_serial_num[i];
// set the count
return TRUE;
}
}
else
OWERROR(OWERROR_READCOM_FAILED);
}
else
OWERROR(OWERROR_WRITECOM_FAILED);
// an error occured so re-sync with DS2480
DS2480Detect(portnum);
// reset the search
LastDiscrepancy[portnum] = 0;
LastDevice[portnum] = FALSE;
LastFamilyDiscrepancy[portnum] = 0;
return FALSE;
}
//--------------------------------------------------------------------------
// 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)
{
SETUP_PACKET setup;
short rt=FALSE,i,ResetSearch=FALSE;
BYTE rom_buf[16];
BYTE ret_buf[16];
WORD buf_len;
uchar lastcrc8;
WORD nBytes = 8;
ULONG nOutput = 0;
long limit;
STATUS_PACKET status;
BYTE nResult;
// if the last call was the last one
if (LastDevice[portnum])
{
// reset the search
LastDiscrepancy[portnum] = 0;
LastDevice[portnum] = FALSE;
LastFamilyDiscrepancy[portnum] = 0;
return FALSE;
}
// check if reset first is requested
if (do_reset)
{
// reset the 1-wire
// extra reset if last part was a DS1994/DS2404 (due to alarm)
if ((SerialNum[portnum][0] & 0x7F) == 0x04)
owTouchReset(portnum);
// if there are no parts on 1-wire, return FALSE
if (!owTouchReset(portnum))
{
// reset the search
LastDiscrepancy[portnum] = 0;
LastFamilyDiscrepancy[portnum] = 0;
OWERROR(OWERROR_NO_DEVICES_ON_NET);
return FALSE;
}
}
// build the rom number to put to the USB chip
for (i = 0; i < 8; i++)
rom_buf[i] = SerialNum[portnum][i];
// take into account LastDiscrepancy
if (LastDiscrepancy[portnum] != 0xFF)
{
if (LastDiscrepancy[portnum] > 0)
bitacc(WRITE_FUNCTION,1,(short)(LastDiscrepancy[portnum] - 1),rom_buf);
for (i = LastDiscrepancy[portnum]; i < 64; i++)
bitacc(WRITE_FUNCTION,0,i,rom_buf);
}
// put the ROM ID in EP2
nBytes = 8;
if (!DS2490Write(usbhnd[portnum], rom_buf, &nBytes))
{
AdapterRecover(portnum);
return FALSE;
}
// setup for search command call
setup.RequestTypeReservedBits = 0x40;
setup.Request = COMM_CMD;
setup.Value = COMM_SEARCH_ACCESS | COMM_IM | COMM_SM | COMM_F | COMM_RTS;
// the number of devices to read (1) with the search command
setup.Index = 0x0100 | (((alarm_only) ? 0xEC : 0xF0) & 0x00FF);
setup.Length = 0;
setup.DataOut = FALSE;
// call the driver
if (!DeviceIoControl(usbhnd[portnum],
DS2490_IOCTL_VENDOR,
&setup,
sizeof(SETUP_PACKET),
NULL,
0,
&nOutput,
NULL))
{
// failure
AdapterRecover(portnum);
return FALSE;
}
// set a time limit
limit = msGettick() + 200;
// loop to wait on EP3 ready (device will go idle)
do
{
// read the status to see if the pulse has been stopped
if (!DS2490GetStatus(usbhnd[portnum], &status, &nResult))
{
// failure
break;
}
else
{
// look for any fail conditions
for (i = 0; i < nResult; i++)
{
// only check for error conditions when the condition is not a ONEWIREDEVICEDETECT
if (status.CommResultCodes[i] != ONEWIREDEVICEDETECT)
{
// failure
break;
}
}
}
}
while (((status.StatusFlags & STATUSFLAGS_IDLE) == 0) &&
(limit > msGettick()));
// check results of the waite for idel
if ((status.StatusFlags & STATUSFLAGS_IDLE) == 0)
{
AdapterRecover(portnum);
return FALSE;
}
// check for data
if (status.ReadBufferStatus > 0)
{
// read the load
buf_len = 16;
if(!DS2490Read(usbhnd[portnum], ret_buf, &buf_len))
{
AdapterRecover(portnum);
return FALSE;
}
// success, get rom and desrepancy
LastDevice[portnum] = (buf_len == 8);
// extract the ROM (and check crc)
setcrc8(portnum,0);
for (i = 0; i < 8; i++)
{
SerialNum[portnum][i] = ret_buf[i];
lastcrc8 = docrc8(portnum,ret_buf[i]);
}
// crc OK and family code is not 0
if (!lastcrc8 && SerialNum[portnum][0])
{
// loop through the descrepancy to get the pointers
for (i = 0; i < 64; i++)
{
// if descrepancy
if (bitacc(READ_FUNCTION,0,i,&ret_buf[8]) &&
(bitacc(READ_FUNCTION,0,i,&ret_buf[0]) == 0))
{
LastDiscrepancy[portnum] = i + 1;
}
}
rt = TRUE;
}
else
{
ResetSearch = TRUE;
rt = FALSE;
}
}
// check if need to reset search
if (ResetSearch)
{
LastDiscrepancy[portnum] = 0xFF;
LastDevice[portnum] = FALSE;
for (i = 0; i < 8; i++)
SerialNum[portnum][i] = 0;
}
return rt;
}
//--------------------------------------------------------------------------
// 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;
}