Component: Thermocouple (MAX31855 / BL0126) (Environmental): Difference between revisions

Revision as of 14:23, 13 July 2026

Author	Matrix TSL
Version	1.0
Category	Environmental

Thermocouple (MAX31855 / BL0126) component

Component to interface the MAX31855 IC from MAXIM. Uses a standard 3-wire SPI interface to connect to the IC and collect the temperature. IC available in different versions to suit different thermocouple types.

Version information

Library Version, Component Version, Date, Author, Info
8, 1.0, 08-05-25, BR, Added autodetect port on Ev_PostInitialise

Detailed description

No detailed description exists yet for this component

Examples

Example program showing how to use the Thermocouple component. MAX31855_Example

Macro reference

Initialise

	Initialise
Configures the SPI bus ready for communications.
- VOID	Return

ReadReference_Float

	ReadReference_Float
Returns the reference temperature from the last sample as a floating point value in Degrees C.
- FLOAT	Return

ReadReference_Int

	ReadReference_Int
Returns the reference temperature from the last sample as an integer value in Degrees C.
- INT	Return

ReadThermocouple_Float

	ReadThermocouple_Float
Returns the thermocouple temperature from the last sample as a floating point value in Degrees C.
- FLOAT	Return

ReadThermocouple_Int

	ReadThermocouple_Int
Returns the thermocouple temperature from the last sample as an integer value in Degrees C.
- INT	Return

Sample

	Sample
Reads the memory of the MAX31855 IC and checks for errors. Must be called before any of the Read functions. Returns: 0=OK, 1=Open Circuit, 2=Short GND, 3=Short VCC
- BYTE	Return

Property reference

	Properties
	Thermocouple Properties
	Thermocouple Type
Specified at the end of the MAX part number MAX31855X where X is the Thermocouple type. Selects which type of thermocouple the IC works with.
	SPI Properties
	Channel
SPI Channel selector
	Prescale
Prescale option selector
	MOSI
SPI Data Out Pin SDO - Also Known as Master Out Slave In (MOSI) when used in Master mode.
	MISO
SPI Data In Pin SDI - Also Known as Master In Slave Out (MISO) when used in Master mode.
	CLK
SPI Clock Pin CLK - The Clock signal is driven by the SPI master.
	CS / SS
Chip Select / Slave Select Pin Master Mode: General purpose output pin used to select the remote SPI device. Slave Mode: Hardware chip select pin input used to select the SPI device.
	Simulation
	Simulate Comms

Component Source Code

Please click here to download the component source project: FC_Comp_Source_ThermocoupleMAX31855.fcfx

Please click here to view the component source code (Beta): FC_Comp_Source_ThermocoupleMAX31855.fcfx

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 | colspan="2" | Configures the SPI bus ready for communications.&nbsp;
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-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''ReadReference_Float'''
+| width="90%" class="mtx-class-macrohead" | '''ReadReference_Float'''
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 | colspan="2" | Returns the reference temperature from the last sample as a floating point value in Degrees C.&nbsp;
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+| width="90%" class="mtx-class-macrohead" | '''ReadReference_Int'''
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 | colspan="2" | Returns the reference temperature from the last sample as an integer value in Degrees C.&nbsp;
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+| width="90%" class="mtx-class-macrohead" | '''ReadThermocouple_Float'''
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 | colspan="2" | Returns the thermocouple temperature from the last sample as a floating point value in Degrees C.&nbsp;
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+| width="90%" class="mtx-class-macrohead" | '''ReadThermocouple_Int'''
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+| width="90%" class="mtx-class-macrohead" | '''Sample'''
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 | colspan="2" | Reads the memory of the MAX31855 IC and checks for errors. Must be called before any of the Read functions. Returns: 0=OK, 1=Open Circuit, 2=Short GND, 3=Short VCC&nbsp;
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+| width="90%" class="mtx-class-macrohead" | '''Properties'''
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