Component: Barometer (BME280) (Environmental): Difference between revisions

Latest revision as of 14:36, 13 July 2026

Author	Matrix TSL
Version	1.3
Category	Environmental

Barometer (BME280) component

A small PCB surface mount barometric pressure sensor with a I2C bus interface. Pressure range 300 to 1100 hPa. Temperature range -40 to +85 °C. Works with I2C interface only.

Detailed description

No detailed description exists yet for this component

Examples

BME280 Barometer plus Altitude v1.0 This example reads and displays the pressure, temperature & humidity. If the pressure is increasing then Rise will be displayed.

Alternatively if the pressure is falling, then Fall will be displayed.

The altitude displayed is calculated based on the current pressure reading.

What makes the altitude useful is the ability to tare it, then after going up or downstairs for example the feet & meters are displayed.

Note since the altitude is calculated based on pressure, then if the sensor is left at the same height, the height displayed can be different each day.

Circuit Diagram

Macro reference

Forced_Read

	Forced_Read

- VOID	Return

I2C_Read_Register

	I2C_Read_Register
Reads a byte value from a register on the device
- BYTE	Address

- BYTE	Return

I2C_Write_Register

	I2C_Write_Register
Writes a byte value to a register on the device
- BYTE	Address

- BYTE	Value

- VOID	Return

Initialise

	Initialise
Starts up the I2C bus and initialises the pressure sensor ready for use. Returns 1 for a sucessful startup. Returns 0 for a failed startup or no device detected.
- BYTE	Return

ReadHumidityFloat

	ReadHumidityFloat
Reads the humidity as a floating point value in percentage 0-100%. Calls the ReadHumidityRaw function and then converts to a meaningful value.
- FLOAT	Return

ReadPressureFloat

	ReadPressureFloat
Reads the pressure as a floating point value in Bars. Calls the ReadPressureRaw function and then converts to a meaningful value.
- FLOAT	Return

ReadTemperatureFloat

	ReadTemperatureFloat
Reads the temperature as a floating point value in °C. Resultion sets the return bit value and conversion time. Calls the ReadTemperatureRaw function and then converts to a meaningful value.
- FLOAT	Return

Reset

	Reset
Resets the device
- VOID	Return

Uninit

	Uninit
Uninitialse and release I2C resources
- VOID	Return

Property reference

	Properties
	Connections
	Slave Address

	Channel
Channel selection
	Baud Select
Baud rate option selector
	Baud Rate
Baud rate to be used
	Stop Delay
On older microcontroller devices there is a potential for the I2C hardware channel to lock up if there is not a 10ms delay between an I2C stop event and the next I2C start event. Most modern microcontrollers will not have a problem so this property can be disabled to speed up the I2C communications.
	SDA
Pin used for SDA (data signal)
	SCL
Pin used for SCL (clock signal)
	Sensor Options
	Compensation
Compensation formulas in double precision floating point or 32 bit fixed point
	Humidity Oversampling

	Pressure Oversampling

	Temperature Oversampling

	Mode

	Standby Normal Mode (ms)

	Filter Coefficient

	Simulation
	Simulate Comms
Allows the simulation data to come from the panel GUI or relayed via an injector component.

Component Source Code

Please click here to download the component source project: FC_Comp_Source_Pressure_Sensor_BME280.fcfx

Please click here to view the component source code (Beta): FC_Comp_Source_Pressure_Sensor_BME280.fcfx

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-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''I2C_Read_Register'''
+| width="90%" class="mtx-class-macrohead" | '''I2C_Read_Register'''
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 | colspan="2" | Reads a byte value from a register on the device&nbsp;
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-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''I2C_Write_Register'''
+| width="90%" class="mtx-class-macrohead" | '''I2C_Write_Register'''
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-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''Initialise'''
+| width="90%" class="mtx-class-macrohead" | '''Initialise'''
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 | colspan="2" | Starts up the I2C bus and initialises the pressure sensor ready for use. Returns 1 for a sucessful startup. Returns 0 for a failed startup or no device detected.&nbsp;
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-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''ReadHumidityFloat'''
+| width="90%" class="mtx-class-macrohead" | '''ReadHumidityFloat'''
 |-
 | colspan="2" | Reads the humidity as a floating point value in percentage 0-100%. Calls the ReadHumidityRaw function and then converts to a meaningful value.&nbsp;
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-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''ReadPressureFloat'''
+| width="90%" class="mtx-class-macrohead" | '''ReadPressureFloat'''
 |-
 | colspan="2" | Reads the pressure as a floating point value in Bars. Calls the ReadPressureRaw function and then converts to a meaningful value.&nbsp;
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 | width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''ReadTemperatureFloat'''
+| width="90%" class="mtx-class-macrohead" | '''ReadTemperatureFloat'''
 |-
 | colspan="2" | Reads the temperature as a floating point value in °C. Resultion sets the return bit value and conversion time. Calls the ReadTemperatureRaw function and then converts to a meaningful value.&nbsp;
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-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''Reset'''
+| width="90%" class="mtx-class-macrohead" | '''Reset'''
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 | colspan="2" | Resets the device&nbsp;
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-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''Uninit'''
+| width="90%" class="mtx-class-macrohead" | '''Uninit'''
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 | colspan="2" | Uninitialse and release I2C resources&nbsp;
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-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''Properties'''
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+| width="10%" align="center" class="mtx-class-propfolder" | [[File:Fc9-conn-icon.png]]
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 | colspan="2" | Pin used for SCL (clock signal)&nbsp;
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+| width="10%" align="center" class="mtx-class-propfolder" | [[File:Fc9-conn-icon.png]]
-| width="90%" style="background-color:#EAE1EA; color:#4B008D;" | Sensor Options
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+| width="10%" align="center" class="mtx-class-propfolder" | [[File:Fc9-conn-icon.png]]
-| width="90%" style="background-color:#EAE1EA; color:#4B008D;" | Simulation
+| width="90%" class="mtx-class-propfolder" | Simulation
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