Difference between revisions of "Component: Thermocouple (MAX31856) (Environmental)"

Latest revision as of 08:59, 9 June 2025

Author	Matrix TSL
Version	1.0
Category	Environmental

Thermocouple (MAX31856) component

Component to interface the MAX31856 IC from MAXIM. Uses a standard 4-wire SPI interface to connect to the IC and collect the temperature. Compatible with different thermocouple types.

Detailed description

No detailed description exists yet for this component

Examples

No additional examples

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=Under/Over Voltage, 3=Out of range
- BYTE	Return

WriteColdJunctionOffset

	WriteColdJunctionOffset
When Cold Junction Compensation is enabled mode this macro allows you to define the offset temperature of the cold junction.
- FLOAT	OffsetTemperature
Range: +/- 7 Degrees
- VOID	Return

WriteColdJunctionTemperature

	WriteColdJunctionTemperature
When Cold Junction Compensation is disabled/external mode this macro allows you to define the temperature of the cold junction.
- FLOAT	Temperature
Range: +/- 127 Degrees
- VOID	Return

Property reference

	Properties
	Thermocouple Properties
	Thermocouple Type
Specified the thermocouple type used with the sensor IC
	Averaging
Select the number of samples used to provide stable readings.
	Conversion Mode

	Notch Filter
Choose the frequency of notch filter
	Cold Junction Compensation
Allows the chip to automatically perform cold junction compensation to try and get more accurate temperature conversions. Internal - Uses internal temperature sensor External / Disabled- Uses SetColdJunctionTemperature macro to allow for external temperature compensation.
	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_ThermocoupleMAX31856.fcfx

Please click here to view the component source code (Beta): FC_Comp_Source_ThermocoupleMAX31856.fcfx

@@ Line 139: / Line 139: @@
 | width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''Sample'''
 |-
-| 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;
+| 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=Under/Over Voltage, 3=Out of range&nbsp;
 |-
 |-
 | width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-u8-icon.png]] - BYTE
+| width="90%" style="border-top: 2px solid #000;" | ''Return''
+|}
+===WriteColdJunctionOffset===
+{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
+|-
+| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
+| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''WriteColdJunctionOffset'''
+|-
+| colspan="2" | When Cold Junction Compensation is enabled mode this macro allows you  to define the offset temperature of the cold junction.&nbsp;
+|-
+|-
+| width="10%" align="center" | [[File:Fc9-f32-icon.png]] - FLOAT
+| width="90%" | OffsetTemperature
+|-
+| colspan="2" | Range: +/- 7 Degrees&nbsp;
+|-
+| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-void-icon.png]] - VOID
+| width="90%" style="border-top: 2px solid #000;" | ''Return''
+|}
+===WriteColdJunctionTemperature===
+{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
+|-
+| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
+| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''WriteColdJunctionTemperature'''
+|-
+| colspan="2" | When Cold Junction Compensation is disabled/external mode this macro allows you  to define the temperature of the cold junction.&nbsp;
+|-
+|-
+| width="10%" align="center" | [[File:Fc9-f32-icon.png]] - FLOAT
+| width="90%" | Temperature
+|-
+| colspan="2" | Range: +/- 127 Degrees&nbsp;
+|-
+| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-void-icon.png]] - VOID
 | width="90%" style="border-top: 2px solid #000;" | ''Return''
 |}
@@ Line 168: / Line 206: @@
 |-
 | colspan="2" | Select the number of samples used to provide stable readings.&nbsp;
+|-
+| width="10%" align="center" | [[File:Fc9-type-16-icon.png]]
+| width="90%" | Conversion Mode
+|-
+| colspan="2" | &nbsp;
 |-
 | width="10%" align="center" | [[File:Fc9-type-16-icon.png]]
@@ Line 173: / Line 216: @@
 |-
 | colspan="2" | Choose the frequency of notch filter&nbsp;
+|-
+| width="10%" align="center" | [[File:Fc9-type-16-icon.png]]
+| width="90%" | Cold Junction Compensation
+|-
+| colspan="2" | Allows the chip to automatically perform cold junction compensation to try and get more accurate temperature conversions. Internal - Uses internal temperature sensor External / Disabled- Uses SetColdJunctionTemperature macro to allow for external temperature compensation.&nbsp;
 |-
 | width="10%" align="center" style="background-color:#EAE1EA;" | [[File:Fc9-conn-icon.png]]