Component: Barometer (BME280) (Environmental)

Author	Matrix TSL
Version	1.3
Category	Environmental

Barometer 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

Downloadable macro reference

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

	Reset
Resets the device
- VOID	Return

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

	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.
[[File:]] -	Return

	Forced_Read
- VOID	Return

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

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

	Uninit
Uninitialse and release I2C resources
- VOID	Return

	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

	UpdateAccelerometerData
Reads from the accelerometer and updates the local XYZ variables. Returns 1 for new data and 0 for no new data
- BYTE	Return

	SimSetCompass
Allows the XYZ slider values to be set via the simulation
[[File:]] -	X
[[File:]] -	Y
[[File:]] -	Z
- VOID	Return

	Read_Bearing
Reads the current sensor compass bearing based on degrees CW from magnetic north. Returns 0-359 where 0 = North, 90 = East, 180 = South, 270 = West Requires the ArcTan floating point function to be available to work correctly. Supported on AVR, 16-bit
- BYTE	NumSamples
The number of readings to base the bearing on
- UINT	Return

	Initialise
Sets up up the communication bus and initialises the accelerometer module. Returns 0 for success and > 0 for fail.
- BYTE	Return

	IOSetOutputPin
Sets the selected digital pin to an output and assigns the output state.
- BYTE	Pin
Range: 0-29
[[File:]] -	State
Range: 0-1
- VOID	Return

	UARTReceive
Receives a data byte from the UART. Recommend calling the UARTCheckRx function first to ensure data is available.
- BYTE	Channel
Channel Index: Range 0 - UART Bus Count - 1
- BYTE	Return

	ADCSampleAverage10
Reads the voltage present on an Analog pin as an 10-bit value range 0-1023. Performs the selected number of samples with the selected time in microseconds in between samples
- BYTE	ADCChannel
Range: 0, 3-7
- BYTE	SampleCount
Range: 1- 100
- BYTE	SampleDelay
Delay in us between each sample
- UINT	Return

	OneWireScanBus
Scans the one wire bus to detect all connected devices. Returns the number of one wire devices found.
- BYTE	Channel
Channel Index: Range 0 - I2C Bus Count - 1
- BYTE	Return

	SPIInitialise
Initialsie the SPI module ready for communications
- BYTE	Channel
Channel Index: Range 0 - SPI Bus Count - 1
- VOID	Return

	OneWireReceiveByte
Receives a byte from the one wire bus a bit at a time
- BYTE	Channel
Channel Index: Range 0 - I2C Bus Count - 1
- BYTE	Return

	I2CSend
Transmit a byte using the I2C bus
- BYTE	Channel
Channel Index: Range 0 - I2C Bus Count - 1
- BYTE	DataOut
[[File:]] -	Return

	UARTSend
Send a byte via the UART module
- BYTE	Channel
Channel Index: Range 0 - UART Bus Count - 1
- BYTE	Data
Data Byte to send. Range: 0-255
- VOID	Return

	OneWireGetDeviceCount
Returns the number of devices found by the last ScanBus operation.
- BYTE	Channel
Channel Index: Range 0 - I2C Bus Count - 1
- BYTE	Return

	PWMSetPrescaler
Sets the prescaler for the PWM output
- BYTE	Channel
Range: 0 - 11
- BYTE	Prescaler
- BYTE	Period
- VOID	Return

	PWMEnable
Enable a PWM output
- BYTE	Channel
Range: 0-11
- VOID	Return

	ADCSampleArray10
Reads the voltage present on an Analog pin as an 10-bit value range 0-1023 Performs the selected number of samples with the selected time in microseconds in between samples and returns each sample in a single packet
- BYTE	ADCChannel
Range: 0, 3-7
- BYTE	SampleCount
Range: 1- 32
- UINT	SampleDelay
Delay in us between each sample
- UINT	Samples
10-bit samples returned from the function
- VOID	Return

	ADCSampleAverage8
Reads the voltage present on an Analog pin as an 8-bit value range 0-255 Performs the selected number of samples with the selected time in microseconds in between samples
- BYTE	ADCChannel
Range: 0, 3-7
- BYTE	SampleCount
Range: 1- 100
- BYTE	SampleDelay
Delay in us between each sample
- BYTE	Return

	Initialise
Initialise the comms to the Arduino board ready for commands to be sent.
- VOID	Return

	PWMEnable
Allows pulse width modulated transistor outputs to be switched on or off. Bit 0 = Enable AB Bit 1 = A / Bit 2 = B Bit 3 = C / Bit 4 = D Bit 5 = Enable CD
- BYTE	EnableMask
Range 0-63 or 0b00000 to 0b111111
- VOID	Return

	Initialise
- VOID	Return

Property reference

	Properties
	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
	Scope Traces
Selects if the component pin connections are automatically generated on the data recorder window or not. Yes: Automatically add the component pins to a group on the data recorder which will reflect the sim data during simultion. No: Do not show the pin signals on the data recorder window.
	Console Data
Selects if the console data is automatically generated or not
	API
	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)
	Simulations
	Simulate Comms
Allows the simulation data to come from the panel GUI or relayed via an injector component.