/*****************************************************************************
* Function name : DS18B20_StartAllDevicesConverting
* Parameters : bus - вывод микроконтроллера, который выполн¤ет роль 1WIRE шины
* Purpose : «апускает измерение на всех устройствах одновременно,
* ждет окончани¤ преобразовани¤
*****************************************************************************/
void DS18B20_StartAllDevicesConverting(unsigned char bus){
OWI_DetectPresence(bus);
OWI_SkipRom(bus);
OWI_SendByte(DS18B20_CONVERT_T, bus);
/*ждем, когда датчик завершит преобразование*/
//while (!OWI_ReadBit(bus));
_delay_ms(750);
}
/*
* owiADCConvert(unsigned char bus_pattern, unsigned char * id)
*
*
* this function implements the convert function
* using the 0x3C command
*
* CRC checks are not performed
*
* input:
* bus_pattern:
* pattern of bus lines to send command to
* id :
* 1-wire device id 8 byte char array
* - if set, i.e. not NULL, only device with this id is addressed (MATCH_ROM)
* - else every device is used (ROM_SKIP)
*
* return:
* 0: ok
* 1: failed
*
*/
uint8_t owiADCConvert(unsigned char currentPins, unsigned char * id)
{
printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("bus_pattern: %#x starting conversion sequence"), currentPins );
static uint16_t maxConversionTime = OWI_ADC_MAX_CONVERSION_TIME_MILLISECONDS;
static uint32_t count;
static uint32_t maxcount;
static unsigned char timeout_flag;
uint8_t trialsCounter = 0;
uint8_t result = RESULT_OK;
uint16_t receive_CRC;
maxcount = ( OWI_ADC_CONVERSION_DELAY_MILLISECONDS > 0 ) ? maxConversionTime / OWI_ADC_CONVERSION_DELAY_MILLISECONDS : 1;
count = maxcount;
timeout_flag = FALSE;
/*
* CONVERT [3CH]
*
* The Convert command is used to initiate the analog to digital conversion for one or more channels at the
* resolution specified in memory page 1, control/status data. The conversion takes between 60 and 80 μs
* per bit plus an offset time of maximum 160 μs every time the convert command is issued. For four
* channels with 12-bit resolution each, as an example, the convert command will not take more than
* 4x12x80 μs plus 160 μs offset, which totals 4 ms. If the DS2450 gets its power through the VCC pin, the
* bus master may communicate with other devices on the 1-Wire bus while the DS2450 is busy with A/D
* conversions. If the device is powered entirely from the 1-Wire bus, the bus master must instead provide a
* strong pullup to 5V for the estimated duration of the conversion in order to provide sufficient energy.
*
* The conversion is controlled by the input select mask (Figure 7a) and the read-out control byte (Figure
* 7b). In the input select mask the bus master specifies which channels participate in the conversion. A
* channel is selected if the bit associated to the channel is set to 1. If more than one channel is selected, the
* conversion takes place one channel after another in the sequence A, B, C, D, skipping those channels that
* are not selected. The bus master can read the result of a channel’s conversion before the conversion of all
* the remaining selected channels is completed. In order to distinguish between the previous result and the
* new value the bus master uses the read-out control byte. This byte allows presetting the conversion readout
* registers for each selected channel to all 1’s or all 0’s. If the expected result is close to 0 then one
* should preset to all 1’s or to all 0’s if the conversion result will likely be a high number. In applications
* where the bus master can wait until all selected channels are converted before reading, a preset of the
* read-out registers is not necessary. Note that for a channel not selected in the input select mask, the
* channel’s read-out control setting has no effect. If a channel constantly yields conversion results close to
* 0 the channel’s output transistor may be conducting. See section Device Registers for details.
*
* INPUT SELECT MASK (CONVERSION COMMAND) Figure 7a
* bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
* “don’t care” D C B A
*
* READ-OUT CONTROL (CONVERSION COMMAND) Figure 7b
* bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
* Set D Clear D Set C Clear C Set B Clear B Set A Clear A
*
* Set Clear Explanation
* 0 0 no preset, leave as is
* 0 1 preset to all 0’s
* 1 0 preset to all 1’s
* 1 1 (illegal code)
*
* Following the Convert command byte the bus master transmits the input select mask and the read-out
* control byte. Now the bus master reads the CRC16 of the command byte, select mask and control byte.
* The conversion will start no earlier than 10 μs after the most significant bit of the CRC is received by the
* bus master.
*
* With a parasitic power supply the bus master must activate the strong pullup within this 10 μs window for
* a duration that is estimated as explained above. After that, the data line returns to an idle high state and
* communication on the bus can resume. The bus master would normally send a reset pulse to exit the
* Convert command. Read data time slots generated after the strong pullup has ended but before issuing a
* reset pulse should result in all 1’s if the conversion time was calculated correctly.
*
* With VCC power supply the bus master may either send a reset pulse to exit the Convert command or
* continuously generate read data time slots. As long as the DS2450 is busy with conversions the bus
* master will read 0’s. After the conversion is completed the bus master will receive 1’s instead. Since in a
* open-drain environment a single 0 overwrites multiple 1’s the bus master can monitor multiple devices
* converting simultaneously and immediately knows when the last one is ready. As in the parasite
* powered scenario the bus master finally has to exit the Convert command by issuing a rest pulse.
*
* from data sheet: http://datasheets.maximintegrated.com/en/ds/DS2450.pdf
*/
while( trialsCounter < OWI_SEND_BYTE_MAX_TRIALS )
{
trialsCounter++;
receive_CRC = 0;
result = RESULT_OK;
printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("bus_pattern: %#x sending command, mask, readout byte"),currentPins );
/* select one or all, depending if id is given */
if ( NULL == id)
{
/*
* SKIP ROM [CCH]
*
* This command can save time in a single drop bus system by allowing the bus master to access the
* memory/convert functions without providing the 64-bit ROM code. If more than one slave is present on
* the bus and a read command is issued following the Skip ROM command, data collision will occur on the
* bus as multiple slaves transmit simultaneously (open drain pulldowns will produce a wired-AND result).
*/
OWI_SkipRom(currentPins);
result = owiSendBytesAndCheckCRC16(currentPins, 3,
DS2450_CONVERT, DS2450_CONVERSION_CHANNEL_SELECT_MASK, DS2450_CONVERSION_READOUT_CONTROL);
result = RESULT_OK; /*disable CRC check for skip rom*/
}
else
{
/*
* MATCH ROM [55H]
*
* The match ROM command, followed by a 64-bit ROM sequence, allows the bus master to address a
* specific DS2450 on a multidrop bus. Only the DS2450 that exactly matches the 64-bit ROM sequence
* will respond to the following memory/convert function command. All slaves that do not match the 64-bit
* ROM sequence will wait for a reset pulse. This command can be used with a single or multiple devices
* on the bus.
*/
OWI_MatchRom(id, currentPins); // Match id found earlier
result = owiSendBytesAndCheckCRC16(currentPins, 3,
DS2450_CONVERT, DS2450_CONVERSION_CHANNEL_SELECT_MASK, DS2450_CONVERSION_READOUT_CONTROL);
result = RESULT_OK; /*disable CRC check for skip rom*/
}
// printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("crc16 checksum 3 bytes %#x ?"), owiComputeCRC16(0x0000, 3, DS2450_CONVERT, DS2450_CONVERSION_CHANNEL_SELECT_MASK, DS2450_CONVERSION_READOUT_CONTROL) );
// printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("crc16 checksum 4 bytes %#x ?"), owiComputeCRC16(0x0000, 4, OWI_ROM_SKIP, DS2450_CONVERT, DS2450_CONVERSION_CHANNEL_SELECT_MASK, DS2450_CONVERSION_READOUT_CONTROL) );
// printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("crc16 checksum 3 bytes %#x ?"), owiComputeCRC16(0xFFFF, 3, DS2450_CONVERT, DS2450_CONVERSION_CHANNEL_SELECT_MASK, DS2450_CONVERSION_READOUT_CONTROL) );
// printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("crc16 checksum 4 bytes %#x ?"), owiComputeCRC16(0xFFFF, 4, OWI_ROM_SKIP, DS2450_CONVERT, DS2450_CONVERSION_CHANNEL_SELECT_MASK, DS2450_CONVERSION_READOUT_CONTROL) );
if ( RESULT_OK == result )
{
break;
}
else
{
if (OWI_SEND_BYTE_MAX_TRIALS != trialsCounter)
{
printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("CRC16 check send byte failed - trial no. %i, computed %#x != received %#x"), trialsCounter);
/* ending the Convert command sequence in any case by issuing a Reset Pulse*/
OWI_DetectPresence(currentPins); /*the "DetectPresence" function includes sending a Reset Pulse*/
continue;
}
else
{
CommunicationError_p(ERRG, dynamicMessage_ErrorIndex, TRUE, PSTR("CRC16 check reached max trials (%i) on send byte"), OWI_SEND_BYTE_MAX_TRIALS);
result = RESULT_FAILURE;
break;
}
}
}
//loop that waits for the conversion to be done
if ( RESULT_OK == result )
{
result = RESULT_OK;
while ( OWI_ReadBit(currentPins) == 0 )
{
_delay_ms(OWI_ADC_CONVERSION_DELAY_MILLISECONDS);
/* timeout check */
if ( 0 == --count)
{
timeout_flag = TRUE;
result = RESULT_FAILURE;
break;
}
}
printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("waited %i times a delay of %i ms"), maxcount - count, OWI_ADC_CONVERSION_DELAY_MILLISECONDS);
/* ending the Convert command sequence in any case by issuing a Reset Pulse*/
OWI_DetectPresence(currentPins); /*the "DetectPresence" function includes sending a Reset Pulse*/
}
/* post conversion status analysis*/
if (RESULT_OK == result)
{
owiAdcTimeoutAndFailureBusMask &= ~(currentPins);
result = RESULT_OK;
printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("OWI ADC Conversion failed (bus_pattern: %#x)"), currentPins);
}
else
{
result = RESULT_FAILURE;
if ( NULL == id )
{
owiAdcTimeoutAndFailureBusMask |= currentPins;
if ( FALSE != timeout_flag )
{
CommunicationError_p(ERRG, dynamicMessage_ErrorIndex, TRUE, PSTR("OWI ADC Conversion timeout (bus_pattern: %#x"), currentPins);
printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("OWI Adc Conversion timeout (>%i ms) on bus_mask (%#x)"), maxConversionTime, currentPins);
}
CommunicationError_p(ERRG, dynamicMessage_ErrorIndex, TRUE, PSTR("OWI ADC Conversion failed (bus_pattern: %#x)"), currentPins);
}
else
{
owiCreateIdString(owi_id_string, id);
if ( FALSE != timeout_flag )
{
CommunicationError_p(ERRG, dynamicMessage_ErrorIndex, TRUE, PSTR("OWI ADC Conversion timeout (id: %s"), owi_id_string);
printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("OWI Adc Conversion timeout (>%i ms) (id: %s)"), maxConversionTime, owi_id_string);
}
CommunicationError_p(ERRG, dynamicMessage_ErrorIndex, TRUE, PSTR("OWI ADC Conversion failed (id: %s)"), owi_id_string);
}
}
return result;
}
