herosdevices.hardware.raspberrypi.max318xx.max31855
===================================================

.. py:module:: herosdevices.hardware.raspberrypi.max318xx.max31855

.. autoapi-nested-parse::

   Uses Superclass MAX318xx for communication methods and implements MAX31855 specific functions.







Module Contents
---------------

.. py:function:: temperature_NIST(t_remote: float, t_ambient: float) -> float

   Correct temperature for ambient effects according to the Adafruit library.

   https://github.com/adafruit/Adafruit_CircuitPython_MAX31855/blob/main/adafruit_max31855.py
   This function applies a correction to the remote thermocouple temperature reading based
   on the ambient temperature, using the polynomial approximations from the Adafruit MAX31855
   library.

   :param t_remote: The remote thermocouple junction temperature in Celsius.
   :type t_remote: float
   :param t_ambient: The ambient (cold junction) temperature in Celsius.
   :type t_ambient: float

   :returns: Corrected temperature in Celsius.
   :rtype: float

   :raises RuntimeError: If the total thermoelectric voltage is out of the expected range.


.. py:class:: MAX31855(cs_pins: dict, miso_pin: int = 5, clk_pin: int = 7, invert_sign: bool = False)

   Bases: :py:obj:`herosdevices.hardware.raspberrypi.max318xx.max318xx.MAX318xx`


   Class to interface with MAX31855 thermocouple-to-digital converter.

   :param cs_pin: Chip select GPIO pin. Default is 24.
   :type cs_pin: int
   :param miso_pin: MISO GPIO pin. Default is 5.
   :type miso_pin: int
   :param clk_pin: CLK GPIO pin. Default is 7.
   :type clk_pin: int
   :param invert_sign: Whether to invert the sign of the temperature reading (default: False).
   :type invert_sign: bool

   .. method:: read_temperature()

      Returns the temperature in Celsius.
      


   .. py:attribute:: invert_sign
      :value: False



   .. py:method:: convert_bits(data: list) -> tuple[int, int]
      :staticmethod:


      Convert raw bits from sensor to temperature readings.

      :param data: List of integers representing raw bits.
      :type data: list

      :returns:

                (t_tc, t_ref) where:
                    t_tc (float): Thermocouple temperature.
                    t_ref (float): Cold junction (reference) temperature.
      :rtype: tuple



   .. py:method:: transform_bytes(data: list) -> tuple[int, int]

      Extract temperature data from raw byte list.

      :param data: List of bytes received from sensor.
      :type data: list

      :returns:

                (t_tc, t_ref)
                    t_tc (float): Thermocouple temperature.
                    t_ref (float): Cold junction (reference) temperature.
      :rtype: tuple



   .. py:method:: read_temp(cs_pin: int, num_registers: int, convert: collections.abc.Callable[[float, float], float]) -> float

      Read temperature on port `cs_pin`.



   .. py:attribute:: cs_pins


   .. py:attribute:: miso_pin
      :value: 9



   .. py:attribute:: mosi_pin
      :value: 10



   .. py:attribute:: clk_pin
      :value: 11



   .. py:method:: write_register(reg_num: int, data_byte: int) -> None

      Write a byte to a specified register.

      :param regNum: Register number to write to.
      :type regNum: int
      :param dataByte: Data byte to write.
      :type dataByte: int



   .. py:method:: read_register(cs_pin: int, num_registers: int, reg_num_start: int | None = None) -> list[int]

      Read one or more bytes starting from a specified register.

      :param cs_pin: Chip select GPIO pin number.
      :type cs_pin: int
      :param numRegisters: Number of bytes to read.
      :type numRegisters: int
      :param regNumStart: Starting register number for the read operation.
      :type regNumStart: int, optional

      :returns: List of bytes read from the device.
      :rtype: list



   .. py:method:: send_byte(byte: int) -> None

      Send a byte via SPI by bit-banging.

      :param byte: Byte value to send.
      :type byte: int



   .. py:method:: recv_byte() -> int

      Receive a byte via SPI by bit-banging.

      :returns: Byte received.
      :rtype: int



   .. py:method:: create_dict(values: list[float], observable: str, unit: str) -> dict

      Build dictionary of observables to be returned by the sensor.