Variable ds18b20Const

Type Declaration

• familyCode: number

  The 1-Wire family code that identifies a DS18B20 on the bus.

• buildScratchpad: function

  • buildScratchpad(
        celsius: number,
        resolutionBits: number,
        alarmHigh: number,
        alarmLow: number,
    ): Buffer

    Builds the nine bytes a part in the given state puts on the bus.

    This is the inverse of parseScratchpad, so a node can be written and tested against what a thermometer sends without one attached.

    Parameters

    • celsius: number

      The temperature the part is reading.

    • resolutionBits: number

      The resolution it is configured for, 9 to 12.

    • alarmHigh: number

      The high alarm threshold in whole degrees Celsius.

    • alarmLow: number

      The low alarm threshold in whole degrees Celsius.

    Returns Buffer

    The nine scratchpad bytes in transmission order, CRC last.

    Throws

    If the resolution is not 9, 10, 11, or 12 bits.

• celsius: function

  • celsius(raw: number): number

    Converts a raw temperature register to degrees Celsius.

    Parameters

    • raw: number

      The 16-bit two's-complement register.

    Returns number

    The temperature.

• configByte: function

  • configByte(bits: number): number

    Returns the configuration byte that selects a resolution.

    Parameters

    • bits: number

      The resolution in bits: 9, 10, 11, or 12.

    Returns number

    The byte to write to the configuration register.

    Throws

    If the resolution is not one the part offers.

• crc8: function

  • crc8(data: Uint8Array): number

    Computes the Maxim CRC-8 a 1-Wire device checks its own bytes with.

    Parameters

    • data: Uint8Array

      The bytes the checksum covers.

    Returns number

    The checksum.

• maxConversionMicros: function

  • maxConversionMicros(bits: number): number

    Returns how long a conversion may take at a resolution.

    Parameters

    • bits: number

      The resolution in bits.

    Returns number

    The datasheet's worst case, in microseconds.

    Throws

    If the resolution is not one the part offers.

• microCelsius: function

  • microCelsius(raw: number): number

    Converts a raw temperature register to micro-degrees Celsius.

    Parameters

    • raw: number

      The 16-bit two's-complement register.

    Returns number

    The temperature, exact in integer arithmetic.

• parseScratchpad: function

  • parseScratchpad(bytes: Uint8Array): sensors.Ds18b20Reading

    Parses and CRC-checks a nine-byte scratchpad.

    Parameters

    • bytes: Uint8Array

      The scratchpad as the device sent it, the ninth byte its CRC.

    Returns sensors.Ds18b20Reading

    The decoded reading.

    Throws

    If the CRC does not match, which means the read was corrupted on the bus and should be repeated.

• resolutionBits: function

  • resolutionBits(configByte: number): number

    Returns the resolution a configuration byte selects.

    Parameters

    • configByte: number

      The byte read from the configuration register.

    Returns number

    The resolution in bits.

• stepMicroCelsius: function

  • stepMicroCelsius(bits: number): number

    Returns the temperature step a resolution resolves.

    Parameters

    • bits: number

      The resolution in bits.

    Returns number

    The step in micro-degrees Celsius.

    Throws

    If the resolution is not one the part offers.