自学教程：C++ writeScratchPad函数代码示例

// set resolution of a device to 9, 10, 11, or 12 bits// if new resolution is out of range, 9 bits is used. bool DallasTemperature::setResolution(uint8_t* deviceAddress, uint8_t newResolution){  ScratchPad scratchPad;  if (isConnected(deviceAddress, scratchPad))  {    // DS18S20 has a fixed 9-bit resolution    if (deviceAddress[0] != DS18S20MODEL)    {      switch (newResolution)      {        case 12:          scratchPad[CONFIGURATION] = TEMP_12_BIT;          break;        case 11:          scratchPad[CONFIGURATION] = TEMP_11_BIT;          break;        case 10:          scratchPad[CONFIGURATION] = TEMP_10_BIT;          break;        case 9:        default:          scratchPad[CONFIGURATION] = TEMP_9_BIT;          break;      }      writeScratchPad(deviceAddress, scratchPad);    }	return true;  // new value set  }  return false;}

bool DallasTemperature::setResolution(const uint8_t* deviceAddress, uint8_t newResolution) {    ScratchPad scratchPad;    if (readScratchPadCRC(deviceAddress, scratchPad)) {        // DS18S20 has a fixed 9-bit resolution        if (!isDS18S20Model(deviceAddress)) {            uint8_t resolution;#if REQUIRESONLY12BITCONVERSION            resolution = TEMP_12_BIT;#else						            switch (newResolution) {                case 12:                    resolution = TEMP_12_BIT;                    break;                case 11:                    resolution = TEMP_11_BIT;                    break;                case 10:                    resolution = TEMP_10_BIT;                    break;                case 9:                default:                    resolution = TEMP_9_BIT;                    break;            }#endif			            scratchPad[CONFIGURATION] = resolution;            writeScratchPad(deviceAddress, scratchPad, false);        }        return true; // new value set    }    return false;}

// note if device is not connected it will fail writing the data.void DallasTemperature::setUserData(const uint8_t* deviceAddress, int16_t data){    ScratchPad scratchPad;    if (isConnected(deviceAddress, scratchPad))    {        scratchPad[HIGH_ALARM_TEMP] = data >> 8;        scratchPad[LOW_ALARM_TEMP] = data & 255;        writeScratchPad(deviceAddress, scratchPad);    }}

void DallasTemperature::setLowAlarmTemp(const uint8_t* deviceAddress, char celsius) {    // make sure the alarm temperature is within the device's range    if (celsius > 125) celsius = 125;    else if (celsius < -55) celsius = -55;    ScratchPad scratchPad;    if (readScratchPadCRC(deviceAddress, scratchPad)) {        scratchPad[LOW_ALARM_TEMP] = (uint8_t) celsius;        writeScratchPad(deviceAddress, scratchPad, true);    }}

bool DallasTemperature::initConnection(const uint8_t* deviceAddress) {#if REQUIRESRESETDETECTION    ScratchPad scratchPad;    bool writeSettings = false;    if (isParasitePowered(deviceAddress)) {        return false;    }    // Reload settings from EEPROM so we can skip writing EEPROM if the values are already set    recallScratchpad(deviceAddress);    if (!readScratchPadCRC(deviceAddress, scratchPad)) {        return false;    }#if REQUIRESONLY12BITCONVERSION		    if(scratchPad[CONFIGURATION] != TEMP_12_BIT){        scratchPad[CONFIGURATION] = TEMP_12_BIT;        writeSettings = true;    }#endif    // Make sure that HIGH_ALARM_TEMP is set to zero in EEPROM    // This value will be loaded on power on    if (scratchPad[HIGH_ALARM_TEMP]) { // conditional to avoid wear on eeprom. 			        scratchPad[HIGH_ALARM_TEMP] = 0;        writeSettings = true;    }    if (writeSettings){        writeScratchPad(deviceAddress, scratchPad, true); // save settings to eeprom    }    // Write HIGH_ALARM_TEMP again, but don't save to EEPROM, so that it reverts to 0 on reset    // from this point on, if we read a scratchpad with a 0 value in HIGH_ALARM (detectedReset() returns true)    // it means the device has reset or the previous write of the scratchpad above was unsuccessful.    // Either way, initConnection() should be called again    scratchPad[HIGH_ALARM_TEMP] = 1;    writeScratchPad(deviceAddress, scratchPad, false); #endif    return true;}

// sets the high alarm temperature for a device in degrees celsius// accepts a float, but the alarm resolution will ignore anything// after a decimal point.  valid range is -55C - 125Cvoid DallasTemperature::setHighAlarmTemp(uint8_t* deviceAddress, char celsius){  // make sure the alarm temperature is within the device's range  if (celsius > 125) celsius = 125;  else if (celsius < -55) celsius = -55;  ScratchPad scratchPad;  if (isConnected(deviceAddress, scratchPad))  {    scratchPad[HIGH_ALARM_TEMP] = (uint8_t)celsius;    writeScratchPad(deviceAddress, scratchPad);  }}

// note if device is not connected it will fail writing the data.void DallasTemperature::setUserData(const uint8_t* deviceAddress, int16_t data){    // return when stored value == new value    if(getUserData(deviceAddress) == data) return;    ScratchPad scratchPad;    if (isConnected(deviceAddress, scratchPad))    {        scratchPad[HIGH_ALARM_TEMP] = data >> 8;        scratchPad[LOW_ALARM_TEMP] = data & 255;        writeScratchPad(deviceAddress, scratchPad);    }}

// set resolution of a device to 9, 10, 11, or 12 bits// if new resolution is out of range, 9 bits is used.bool DallasTemperature::setResolution(const uint8_t* deviceAddress, uint8_t newResolution, bool skipGlobalBitResolutionCalculation){	// ensure same behavior as setResolution(uint8_t newResolution)	newResolution = constrain(newResolution, 9, 12);			    // return when stored value == new value    if(getResolution(deviceAddress) == newResolution) return true;    ScratchPad scratchPad;    if (isConnected(deviceAddress, scratchPad)){        // DS1820 and DS18S20 have no resolution configuration register        if (deviceAddress[0] != DS18S20MODEL){            switch (newResolution){            case 12:                scratchPad[CONFIGURATION] = TEMP_12_BIT;                break;            case 11:                scratchPad[CONFIGURATION] = TEMP_11_BIT;                break;            case 10:                scratchPad[CONFIGURATION] = TEMP_10_BIT;                break;            case 9:            default:                scratchPad[CONFIGURATION] = TEMP_9_BIT;                break;            }            writeScratchPad(deviceAddress, scratchPad);            // without calculation we can always set it to max			bitResolution = max(bitResolution, newResolution);						if(!skipGlobalBitResolutionCalculation && (bitResolution > newResolution)){				bitResolution = newResolution;				DeviceAddress deviceAddr;				for (int i=0; i<devices; i++)				{					getAddress(deviceAddr, i);					bitResolution = max(bitResolution, getResolution(deviceAddr));				}			}        }        return true;  // new value set    }    return false;}

// sets the low alarm temperature for a device in degrees Celsius// accepts a float, but the alarm resolution will ignore anything// after a decimal point.  valid range is -55C - 125Cvoid DallasTemperature::setLowAlarmTemp(const uint8_t* deviceAddress, char celsius){        // return when stored value == new value    if(getLowAlarmTemp(deviceAddress) == celsius) return;    // make sure the alarm temperature is within the device's range    if (celsius > 125) celsius = 125;    else if (celsius < -55) celsius = -55;    ScratchPad scratchPad;    if (isConnected(deviceAddress, scratchPad)){        scratchPad[LOW_ALARM_TEMP] = (uint8_t)celsius;        writeScratchPad(deviceAddress, scratchPad);    }}