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LOW_devDS1820 Class Reference

Device class for DS18S20 High-Precision 1-Wire Digital Thermometer. More...

#include <LOW_devDS1820.h>

Inheritance diagram for LOW_devDS1820:

[legend]Collaboration diagram for LOW_devDS1820:

Public Types
typedef std::vector< LOW_devDS1820 *>	devDS1820PtrVec_t
	Vector type of class device pointers. More...
typedef LOW_devDS1820::scratchpadDS1820_t	scratchpadDS1820_t
	DS1820 internal scratchpad as defined by Dallas. More...
typedef std::vector< LOW_device *>	devPtrVec_t
	Vector type of class device pointers. More...
typedef std::map< LOW_deviceID, LOW_device *>	deviceMap_t
	Map type of devices with LOW_deviceID as key. More...
Public Methods
	class_DERIVE_FROM_EXCEPTION (devDS1820_error, LOW_exception)
	Exception base class for all exceptions thrown by LOW_devDS1820. More...
	LOW_devDS1820 (LOW_netSegment &inSegment, const LOW_deviceID &inDevID)
	Real constructor corresponding to static pseudo constructor new_Instance(). More...
	~LOW_devDS1820 ()
	Destructor. More...
virtual string	getFamilyName () const
	Get the device's family name. More...
bool	getIsExternalPowered () const
	Get whether the device is externally powered. More...
void	cmd_ConvertT () const
	Initiate a single temperature conversion. More...
void	cmd_ReadScratchpad (scratchpadDS1820_t *outScratchpad) const
	Read the contents of the scratchpad. More...
void	cmd_WriteScratchpad (const uint8_t inTL, const uint8_t inTH) const
	Write 2 bytes of data to the DS18S20 scratchpad. More...
void	cmd_CopyScratchpad () const
	Copy the contents of the scratchpad TH and TL registers to EEPROM. More...
void	cmd_RecallE2 () const
	Recall the alarm trigger values (TH and TL) from EEPROM and place the data in bytes 2 and 3, respectively, in the scratchpad memory. More...
bool	cmd_ReadPowerSupply () const
	Determine the device is using parasite power. More...
LOW_deviceID	getID () const
	Get the device's ROM ID. More...
LOW_netSegment &	getNetSegment () const
	Get the network segment the device is on. More...
bool	verifyDevice (const bool inOnlyAlarm=false, const bool inDoReset=true) const
	Shortcut method to verify the presence of the device on it's network segment. More...
Static Public Attributes
const LOW_deviceIDRaw::devFamCode_t	familyCode = 0x10
	Family code of this specific device. More...
const string	familyName = "DS1820"
	Family name of this specific device. More...
const owCommand_t	ConvertT_COMMAND = 0x44
	1-Wire command byte constant. More...
const owCommand_t	ReadScratchpad_COMMAND = 0xbe
	1-Wire command byte constant. More...
const owCommand_t	WriteScratchpad_COMMAND = 0x4e
	1-Wire command byte constant. More...
const owCommand_t	CopyScratchpad_COMMAND = 0x48
	1-Wire command byte constant. More...
const owCommand_t	RecallE2_COMMAND = 0xb8
	1-Wire command byte constant. More...
const owCommand_t	ReadPowerSupply_COMMAND = 0xb4
	1-Wire command byte constant. More...
const LOW_deviceIDRaw::devFamCode_t	anyDev_famCode = 0xff
	Family code for selecting any/all device types. More...
const owCommand_t	MatchROM_COMMAND = 0x55
	1-Wire command byte constant. More...
const owCommand_t	ReadROM_COMMAND = 0x33
	1-Wire command byte constant. More...
const owCommand_t	SkipROM_COMMAND = 0xcc
	1-Wire command byte constant. More...
const owCommand_t	SearchROM_COMMAND = 0xf0
	1-Wire command byte constant. More...
const owCommand_t	SearchAlarmROM_COMMAND = 0xec
	1-Wire command byte constant. More...
Protected Methods
LOW_link &	getLink () const
	Get the link the device is on. More...
void	cmd_MatchROM () const
	Shortcut for issuing a matchROM command for a device. More...
Static Protected Methods
LOW_device *	new_Instance (LOW_netSegment &inNetSegment, const LOW_deviceID &inDevID)
	Static pseudo constructor for registering with LOW_deviceFactory. More...
Protected Attributes
bool	isExternalPowered
	Indicating wether the device is externally powered. More...
const LOW_deviceID	ID
	1-Wire ROM ID of the device. More...
LOW_netSegment &	netSegment
	Network segment where the device is located. More...
Static Private Methods
int	initialize ()
	Static inizializer to register the class with LOW_deviceFactory. More...
Static Private Attributes
int	initHelper = initialize()
	Needed for dirty little C++ hack to force static initialization on application start. More...
Friends
class	linkLock
	Needed to grant access to the protected getLink() method. More...

Detailed Description

Device class for DS18S20 High-Precision 1-Wire Digital Thermometer.

DS1820 features:

Unique 1-Wire interface requires only one port pin for communication
Each device has a unique 64-bit serial code stored in an onboard ROM
Multidrop capability simplifies distributed temperature sensing applications
Requires no external components
Can be powered from data line. Power supply range is 3.0V to 5.5V
Measures temperatures from 55°C to +125°C ( 67°F to +257°F)
0.5 C accuracy from 10°C to +85°C
9-bit thermometer resolution
Converts temperature in 750ms (max.)
User-definable nonvolatile (NV) alarm settings
Alarm search command identifies and addresses devices whose temperature is outside of programmed limits (temperature alarm condition)
Applications include thermostatic controls, industrial systems, consumer products, thermometers, or any thermally sensitive system

Author:: Harald Roelle, Helmut Reiser

Definition at line 48 of file LOW_devDS1820.h.

Member Typedef Documentation

typedef std::vector<LOW_devDS1820*> LOW_devDS1820::devDS1820PtrVec_t

Vector type of class device pointers.

Definition at line 87 of file LOW_devDS1820.h.

typedef std::map<LOW_deviceID,LOW_device*> LOW_device::deviceMap_t [inherited]

Map type of devices with LOW_deviceID as key.

Definition at line 97 of file LOW_device.h.

typedef std::vector<LOW_device*> LOW_device::devPtrVec_t [inherited]

Vector type of class device pointers.

Definition at line 96 of file LOW_device.h.
Referenced by LOW_netSegment::searchDevices().

typedef struct LOW_devDS1820::scratchpadDS1820_t LOW_devDS1820::scratchpadDS1820_t

DS1820 internal scratchpad as defined by Dallas.

Constructor & Destructor Documentation

LOW_devDS1820::LOW_devDS1820 ( LOW_netSegment & inSegment,

const LOW_deviceID & inDevID

)

Real constructor corresponding to static pseudo constructor new_Instance().
External power supply status is initially detected here.
Parameters:

inSegment Reference to network segment the device is on.

inDevID Reference to device's ID.

Definition at line 61 of file LOW_devDS1820.cpp.
References cmd_ReadPowerSupply(), cmd_RecallE2(), LOW_helper_msglog::devDS1820_dl, LOW_netSegment::getHasExternalPower(), isExternalPowered, and LOW_helper_msglog::printDebug().
Referenced by new_Instance().

LOW_devDS1820::~LOW_devDS1820 ( )

Destructor.

Definition at line 75 of file LOW_devDS1820.cpp.

Member Function Documentation

LOW_devDS1820::class_DERIVE_FROM_EXCEPTION ( devDS1820_error ,

LOW_exception

)

Exception base class for all exceptions thrown by LOW_devDS1820.

void LOW_devDS1820::cmd_ConvertT ( ) const

Initiate a single temperature conversion.
Following the conversion, the resulting thermal data is stored in the 2-byte temperature register in the scratchpad memory and the DS18S20 returns to its low-power idle state.
The method uses different techniquies to detect the end of the conversion:

If the device is being used in parasite power mode, a strong pullup is enabled on the 1-Wire bus. Conversion ends when strong pullup ends.

If the device is powered by an external supply, the device is actively polled for the end of the conversion.

Definition at line 91 of file LOW_devDS1820.cpp.
References LOW_device::cmd_MatchROM(), ConvertT_COMMAND, LOW_device::getLink(), LOW_device::linkLock, LOW_link::pullUp_1048, LOW_link::readDataBit(), and LOW_link::writeData().
Referenced by LOW_compTempSensor::checkAlarm(), and LOW_compTempSensor::getTemperature().

void LOW_devDS1820::cmd_CopyScratchpad ( ) const

Copy the contents of the scratchpad TH and TL registers to EEPROM.
If the device is being used in parasite power mode, a strong pullup on the 1-Wire bus is enabled.
Definition at line 142 of file LOW_devDS1820.cpp.
References LOW_device::cmd_MatchROM(), CopyScratchpad_COMMAND, LOW_device::getLink(), LOW_device::linkLock, LOW_link::pullUp_1048, and LOW_link::writeData().
Referenced by LOW_compTempSensor::setAlarmLevels().

void LOW_device::cmd_MatchROM ( ) const [protected, inherited]

Shortcut for issuing a matchROM command for a device.
Calls the corresponding method in LOW_netSegment.
Definition at line 102 of file LOW_device.cpp.
References LOW_netSegment::cmd_MatchROM(), and LOW_device::netSegment.
Referenced by LOW_devDS2406::cmd_ChannelAccess::cmd_ChannelAccess(), cmd_ConvertT(), cmd_CopyScratchpad(), LOW_devDS2405::cmd_Match(), cmd_ReadPowerSupply(), cmd_ReadScratchpad(), cmd_RecallE2(), cmd_WriteScratchpad(), LOW_devDS2406::cmd_WriteStatus(), and LOW_devDS2406::readMemUniversal().

bool LOW_devDS1820::cmd_ReadPowerSupply ( ) const

Determine the device is using parasite power.

Returns:
True when device is externally powered. False when on parasite power.

Definition at line 177 of file LOW_devDS1820.cpp.
References LOW_device::cmd_MatchROM(), LOW_device::getLink(), LOW_device::linkLock, LOW_link::readDataBit(), ReadPowerSupply_COMMAND, and LOW_link::writeData().
Referenced by LOW_devDS1820().

void LOW_devDS1820::cmd_ReadScratchpad ( scratchpadDS1820_t * outScratchpad ) const

Read the contents of the scratchpad.
After fully reading the scratchpad a CRC verification is performed.
Parameters:

outScratchpad Pointer to a scratchpad structure which will be filled in.

Exceptions:

LOW_helper_CRC::crc_error Thrown on CRC mismatch in transferred scratchpad.

Definition at line 110 of file LOW_devDS1820.cpp.
References byteVec_t, LOW_helper_CRC::calcCRC8(), LOW_device::cmd_MatchROM(), LOW_device::getLink(), LOW_device::linkLock, LOW_link::readData(), ReadScratchpad_COMMAND, and LOW_link::writeData().
Referenced by LOW_compTempSensor::getAlarmLevels(), and LOW_compTempSensor::getTemperature().

void LOW_devDS1820::cmd_RecallE2 ( ) const

Recall the alarm trigger values (TH and TL) from EEPROM and place the data in bytes 2 and 3, respectively, in the scratchpad memory.
The method uses different techniquies to detect the end of reading:

If the device is being used in parasite power mode, a strong pullup is enabled on the 1-Wire bus. Reading ends when strong pullup ends.

If the device is powered by an external supply, the device is actively polled for the end of reading.

Definition at line 158 of file LOW_devDS1820.cpp.
References LOW_device::cmd_MatchROM(), LOW_device::getLink(), LOW_device::linkLock, LOW_link::pullUp_1048, LOW_link::readDataBit(), RecallE2_COMMAND, and LOW_link::writeData().
Referenced by LOW_devDS1820(), and LOW_compTempSensor::recallAlarmLevels().

void LOW_devDS1820::cmd_WriteScratchpad ( const uint8_t inTL,

const uint8_t inTH

) const

Write 2 bytes of data to the DS18S20 scratchpad.

Parameters:

inTL Byte to write to TL byte of scratchpad.

inTH Byte to write to TH byte of scratchpad.

Definition at line 127 of file LOW_devDS1820.cpp.
References byteVec_t, LOW_device::cmd_MatchROM(), LOW_device::getLink(), LOW_device::linkLock, LOW_link::writeData(), and WriteScratchpad_COMMAND.
Referenced by LOW_compTempSensor::setAlarmLevels().

virtual string LOW_devDS1820::getFamilyName ( ) const [inline, virtual]

Get the device's family name.

Returns:
Family name of the device.

Reimplemented from LOW_device.
Definition at line 131 of file LOW_devDS1820.h.
References familyName.

LOW_deviceID LOW_device::getID ( ) const [inherited]

Get the device's ROM ID.

Returns:
ROM ID of the device.

Definition at line 73 of file LOW_device.cpp.
References LOW_device::ID.
Referenced by LOW_netSegment::buryDevice(), LOW_netSegment::cmd_MatchROM(), LOW_compJalousieController::LOW_compJalousieController(), LOW_netSegment::removeDevice(), and LOW_netSegment::revitalizeDevice().

bool LOW_devDS1820::getIsExternalPowered ( ) const

Get whether the device is externally powered.
No real activity on the 1-Wire bus occures.
Returns:
Boolean value indicating status of external power.

Definition at line 85 of file LOW_devDS1820.cpp.
References isExternalPowered.
Referenced by LOW_compTempSensor::getIsExternalPowered().

LOW_link & LOW_device::getLink ( ) const [protected, inherited]

Get the link the device is on.

Returns:
Link the device is on.

Definition at line 96 of file LOW_device.cpp.
References LOW_netSegment::getLink(), and LOW_device::netSegment.
Referenced by LOW_devDS2406::cmd_ChannelAccess::cmd_ChannelAccess(), cmd_ConvertT(), cmd_CopyScratchpad(), LOW_devDS2405::cmd_MatchRead(), cmd_ReadPowerSupply(), cmd_ReadScratchpad(), cmd_RecallE2(), LOW_devDS2405::cmd_SearchRead(), cmd_WriteScratchpad(), LOW_devDS2406::cmd_WriteStatus(), LOW_devDS2406::cmd_ChannelAccess::readData(), LOW_devDS2406::cmd_ChannelAccess::readDataBit(), LOW_devDS2406::cmd_ChannelAccess::readDataByte(), LOW_devDS2406::readMemUniversal(), LOW_devDS2406::cmd_ChannelAccess::writeData(), and LOW_devDS2406::cmd_ChannelAccess::~cmd_ChannelAccess().

LOW_netSegment & LOW_device::getNetSegment ( ) const [inherited]

Get the network segment the device is on.

Returns:
Nnetwork segment the device is on.

Definition at line 79 of file LOW_device.cpp.
References LOW_device::netSegment.
Referenced by LOW_compJalousieController::LOW_compJalousieController(), and LOW_compTwinSwitch::LOW_compTwinSwitch().

int LOW_devDS1820::initialize ( ) [static, private]

Static inizializer to register the class with LOW_deviceFactory.

See also:
initHelper

Definition at line 36 of file LOW_devDS1820.cpp.
References familyCode, new_Instance(), and LOW_deviceFactory::registerSpecificCtor().

LOW_device * LOW_devDS1820::new_Instance ( LOW_netSegment & inNetSegment,

const LOW_deviceID & inDevID

) [static, protected]

Static pseudo constructor for registering with LOW_deviceFactory.

Parameters:

inSegment Reference to network segment the device is on.

inDevID Reference to device's ID.

Returns:
New dynamic instance of specific device class.

Reimplemented from LOW_device.
Definition at line 49 of file LOW_devDS1820.cpp.
References LOW_devDS1820().
Referenced by initialize().

bool LOW_device::verifyDevice ( const bool inOnlyAlarm = false,

const bool inDoReset = true

) const [inherited]

Shortcut method to verify the presence of the device on it's network segment.

See also:
LOW_netSegment::verifyDevice()

Definition at line 85 of file LOW_device.cpp.
References LOW_device::ID, LOW_device::netSegment, and LOW_netSegment::verifyDevice().
Referenced by LOW_compTwinSwitch::alarmPollLoop(), LOW_compTempSensor::checkAlarm(), LOW_devDS2405::cmd_SearchActive(), LOW_devDS2405::cmd_SearchRead(), and LOW_network::verifyDevice().

Friends And Related Function Documentation

friend class linkLock [friend, inherited]

Needed to grant access to the protected getLink() method.

Definition at line 174 of file LOW_device.h.
Referenced by cmd_ConvertT(), cmd_CopyScratchpad(), LOW_devDS2405::cmd_Match(), LOW_devDS2405::cmd_MatchRead(), cmd_ReadPowerSupply(), cmd_ReadScratchpad(), cmd_RecallE2(), LOW_devDS2405::cmd_SearchActive(), LOW_devDS2405::cmd_SearchRead(), cmd_WriteScratchpad(), and LOW_devDS2406::readMemUniversal().

Member Data Documentation

const LOW_deviceIDRaw::devFamCode_t LOW_device::anyDev_famCode = 0xff [static, inherited]

Family code for selecting any/all device types.

Definition at line 72 of file LOW_device.h.
Referenced by LOW_netSegment::cmd_SearchROM(), LOW_netSegment::getDevice(), LOW_netSegment::getDevices(), and LOW_deviceFactory::registerSpecificCtor().

const owCommand_t LOW_devDS1820::ConvertT_COMMAND = 0x44 [static]

1-Wire command byte constant.

Definition at line 74 of file LOW_devDS1820.h.
Referenced by cmd_ConvertT().

const owCommand_t LOW_devDS1820::CopyScratchpad_COMMAND = 0x48 [static]

1-Wire command byte constant.

Definition at line 77 of file LOW_devDS1820.h.
Referenced by cmd_CopyScratchpad().

const LOW_deviceIDRaw::devFamCode_t LOW_devDS1820::familyCode = 0x10 [static]

Family code of this specific device.

Reimplemented from LOW_device.
Definition at line 69 of file LOW_devDS1820.h.
Referenced by initialize().

const string LOW_devDS1820::familyName = "DS1820" [static]

Family name of this specific device.

Reimplemented from LOW_device.
Definition at line 33 of file LOW_devDS1820.cpp.
Referenced by getFamilyName().

const LOW_deviceID LOW_device::ID [protected, inherited]

1-Wire ROM ID of the device.

Definition at line 182 of file LOW_device.h.
Referenced by LOW_device::getID(), LOW_device::LOW_device(), and LOW_device::verifyDevice().

int LOW_devDS1820::initHelper = initialize() [static, private]

Needed for dirty little C++ hack to force static initialization on application start.

See also:
initialize()

Definition at line 35 of file LOW_devDS1820.cpp.

bool LOW_devDS1820::isExternalPowered [protected]

Indicating wether the device is externally powered.

Definition at line 212 of file LOW_devDS1820.h.
Referenced by getIsExternalPowered(), and LOW_devDS1820().

const owCommand_t LOW_device::MatchROM_COMMAND = 0x55 [static, inherited]

1-Wire command byte constant.

Definition at line 84 of file LOW_device.h.
Referenced by LOW_netSegment::cmd_MatchROM().

LOW_netSegment& LOW_device::netSegment [protected, inherited]

Network segment where the device is located.

Definition at line 183 of file LOW_device.h.
Referenced by LOW_device::cmd_MatchROM(), LOW_device::getLink(), LOW_device::getNetSegment(), LOW_device::LOW_device(), LOW_device::verifyDevice(), and LOW_device::~LOW_device().

const owCommand_t LOW_devDS1820::ReadPowerSupply_COMMAND = 0xb4 [static]

1-Wire command byte constant.

Definition at line 79 of file LOW_devDS1820.h.
Referenced by cmd_ReadPowerSupply().

const owCommand_t LOW_device::ReadROM_COMMAND = 0x33 [static, inherited]

1-Wire command byte constant.

Definition at line 85 of file LOW_device.h.
Referenced by LOW_netSegment::cmd_ReadROM().

const owCommand_t LOW_devDS1820::ReadScratchpad_COMMAND = 0xbe [static]

1-Wire command byte constant.

Definition at line 75 of file LOW_devDS1820.h.
Referenced by cmd_ReadScratchpad().

const owCommand_t LOW_devDS1820::RecallE2_COMMAND = 0xb8 [static]

1-Wire command byte constant.

Definition at line 78 of file LOW_devDS1820.h.
Referenced by cmd_RecallE2().

const owCommand_t LOW_device::SearchAlarmROM_COMMAND = 0xec [static, inherited]

1-Wire command byte constant.

Definition at line 88 of file LOW_device.h.
Referenced by LOW_netSegment::cmd_SearchROM(), and LOW_netSegment::cmd_SearchROMVerify().

const owCommand_t LOW_device::SearchROM_COMMAND = 0xf0 [static, inherited]

1-Wire command byte constant.

Definition at line 87 of file LOW_device.h.
Referenced by LOW_netSegment::cmd_SearchROM(), and LOW_netSegment::cmd_SearchROMVerify().

const owCommand_t LOW_device::SkipROM_COMMAND = 0xcc [static, inherited]

1-Wire command byte constant.

Definition at line 86 of file LOW_device.h.
Referenced by LOW_netSegment::cmd_SkipROM().

const owCommand_t LOW_devDS1820::WriteScratchpad_COMMAND = 0x4e [static]

1-Wire command byte constant.

Definition at line 76 of file LOW_devDS1820.h.
Referenced by cmd_WriteScratchpad().

The documentation for this class was generated from the following files:

Generated on Sun Jan 12 21:07:54 2003 by

LOW_devDS1820 Class Reference

Public Types

Public Methods

Static Public Attributes

Protected Methods

Static Protected Methods

Protected Attributes

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