MQTT - Barometer Bricklet¶

Simple¶

Download (example-simple.txt)

 1# Change XYZ to the UID of your Barometer Bricklet
 2
 3setup:
 4    # Get current air pressure
 5    subscribe to tinkerforge/response/barometer_bricklet/XYZ/get_air_pressure
 6    publish '' to tinkerforge/request/barometer_bricklet/XYZ/get_air_pressure
 7
 8    # Get current altitude
 9    subscribe to tinkerforge/response/barometer_bricklet/XYZ/get_altitude
10    publish '' to tinkerforge/request/barometer_bricklet/XYZ/get_altitude

Callback¶

Download (example-callback.txt)

 1# Change XYZ to the UID of your Barometer Bricklet
 2
 3setup:
 4    # Handle incoming air pressure callbacks
 5    subscribe to tinkerforge/callback/barometer_bricklet/XYZ/air_pressure
 6    publish '{"register": true}' to tinkerforge/register/barometer_bricklet/XYZ/air_pressure # Register air_pressure callback
 7
 8    # Set period for air pressure callback to 1s (1000ms)
 9    # Note: The air pressure callback is only called every second
10    #       if the air pressure has changed since the last call!
11    publish '{"period": 1000}' to tinkerforge/request/barometer_bricklet/XYZ/set_air_pressure_callback_period

Threshold¶

Download (example-threshold.txt)

 1# Change XYZ to the UID of your Barometer Bricklet
 2
 3setup:
 4    # Get threshold callbacks with a debounce time of 10 seconds (10000ms)
 5    publish '{"debounce": 10000}' to tinkerforge/request/barometer_bricklet/XYZ/set_debounce_period
 6
 7    # Handle incoming air pressure reached callbacks
 8    subscribe to tinkerforge/callback/barometer_bricklet/XYZ/air_pressure_reached
 9    publish '{"register": true}' to tinkerforge/register/barometer_bricklet/XYZ/air_pressure_reached # Register air_pressure_reached callback
10
11    # Configure threshold for air pressure "greater than 1025 hPa"
12    publish '{"option": "greater", "min": 1025000, "max": 0}' to tinkerforge/request/barometer_bricklet/XYZ/set_air_pressure_callback_threshold

Basic Functions¶

request/barometer_bricklet/<UID>/get_air_pressure¶

Request:	empty payload
Response:	air_pressure – Type: int, Unit: 1/1000 hPa, Range: [10000 to 1200000]

Returns the air pressure of the air pressure sensor.

If you want to get the air pressure periodically, it is recommended to use the register/barometer_bricklet/<UID>/air_pressure() callback and set the period with request/barometer_bricklet/<UID>/set_air_pressure_callback_period().

request/barometer_bricklet/<UID>/get_altitude¶

Request:	empty payload
Response:	altitude – Type: int, Unit: 1 cm, Range: [-231 to 231 - 1]

Returns the relative altitude of the air pressure sensor. The value is calculated based on the difference between the current air pressure and the reference air pressure that can be set with request/barometer_bricklet/<UID>/set_reference_air_pressure().

If you want to get the altitude periodically, it is recommended to use the register/barometer_bricklet/<UID>/altitude() callback and set the period with request/barometer_bricklet/<UID>/set_altitude_callback_period().

request/barometer_bricklet/<UID>/set_reference_air_pressure¶

Request:	air_pressure – Type: int, Unit: 1/1000 hPa, Range: [0, 10000 to 1200000], Default: 1013250
Response:	no response

Sets the reference air pressure for the altitude calculation. Setting the reference to the current air pressure results in a calculated altitude of 0cm. Passing 0 is a shortcut for passing the current air pressure as reference.

Well known reference values are the Q codes QNH and QFE used in aviation.

request/barometer_bricklet/<UID>/get_reference_air_pressure¶

Request:	empty payload
Response:	air_pressure – Type: int, Unit: 1/1000 hPa, Range: [10000 to 1200000], Default: 1013250

Returns the reference air pressure as set by request/barometer_bricklet/<UID>/set_reference_air_pressure().

Advanced Functions¶

request/barometer_bricklet/<UID>/get_chip_temperature¶

Request:	empty payload
Response:	temperature – Type: int, Unit: 1/100 °C, Range: [-4000 to 8500]

Returns the temperature of the air pressure sensor.

This temperature is used internally for temperature compensation of the air pressure measurement. It is not as accurate as the temperature measured by the Temperature Bricklet or the Temperature IR Bricklet.

request/barometer_bricklet/<UID>/set_averaging¶

Request:	moving_average_pressure – Type: int, Range: [0 to 25], Default: 25 average_pressure – Type: int, Range: [0 to 10], Default: 10 average_temperature – Type: int, Range: [0 to 255], Default: 10
Response:	no response

Sets the different averaging parameters. It is possible to set the length of a normal averaging for the temperature and pressure, as well as an additional length of a moving average for the pressure. The moving average is calculated from the normal averages. There is no moving average for the temperature.

Setting the all three parameters to 0 will turn the averaging completely off. If the averaging is off, there is lots of noise on the data, but the data is without delay. Thus we recommend to turn the averaging off if the Barometer Bricklet data is to be used for sensor fusion with other sensors.

Added in version 2.0.1$nbsp;(Plugin).

request/barometer_bricklet/<UID>/get_averaging¶

Request:	empty payload
Response:	moving_average_pressure – Type: int, Range: [0 to 25], Default: 25 average_pressure – Type: int, Range: [0 to 10], Default: 10 average_temperature – Type: int, Range: [0 to 255], Default: 10

Returns the averaging configuration as set by request/barometer_bricklet/<UID>/set_averaging().

Added in version 2.0.1$nbsp;(Plugin).

request/barometer_bricklet/<UID>/set_i2c_mode¶

Request:	mode – Type: int, Range: See symbols, Default: 0
Response:	no response

Sets the I2C mode. Possible modes are:

• 0: Fast (400kHz)

• 1: Slow (100kHz)

If you have problems with obvious outliers in the Barometer Bricklet measurements, they may be caused by EMI issues. In this case it may be helpful to lower the I2C speed.

It is however not recommended to lower the I2C speed in applications where a high throughput needs to be achieved.

The following symbols are available for this function:

For mode:

• "fast" = 0

• "slow" = 1

Added in version 2.0.3$nbsp;(Plugin).

request/barometer_bricklet/<UID>/get_i2c_mode¶

Request:	empty payload
Response:	mode – Type: int, Range: See symbols, Default: 0

Returns the I2C mode as set by request/barometer_bricklet/<UID>/set_i2c_mode().

The following symbols are available for this function:

For mode:

• "fast" = 0

• "slow" = 1

Added in version 2.0.3$nbsp;(Plugin).

request/barometer_bricklet/<UID>/get_identity¶

Request:

empty payload

Response:

uid – Type: string, Length: up to 8 connected_uid – Type: string, Length: up to 8 position – Type: char, Range: ["a" to "h", "z"] hardware_version – Type: [int, ...], Length: 3 0: major – Type: int, Range: [0 to 255] 1: minor – Type: int, Range: [0 to 255] 2: revision – Type: int, Range: [0 to 255] firmware_version – Type: [int, ...], Length: 3 0: major – Type: int, Range: [0 to 255] 1: minor – Type: int, Range: [0 to 255] 2: revision – Type: int, Range: [0 to 255] device_identifier – Type: int, Range: [0 to 216 - 1] _display_name – Type: string

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.

The device identifier numbers can be found here. If symbolic output is not disabled, the device identifier is mapped to the corresponding name in the format used in topics.

The display name contains the Barometer's name in a human readable form.

Callback Configuration Functions¶

request/barometer_bricklet/<UID>/set_air_pressure_callback_period¶

Request:	period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Response:	no response

Sets the period with which the register/barometer_bricklet/<UID>/air_pressure() callback is triggered periodically. A value of 0 turns the callback off.

The register/barometer_bricklet/<UID>/air_pressure() callback is only triggered if the air pressure has changed since the last triggering.

request/barometer_bricklet/<UID>/get_air_pressure_callback_period¶

Request:	empty payload
Response:	period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by request/barometer_bricklet/<UID>/set_air_pressure_callback_period().

request/barometer_bricklet/<UID>/set_altitude_callback_period¶

Request:	period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Response:	no response

Sets the period with which the register/barometer_bricklet/<UID>/altitude() callback is triggered periodically. A value of 0 turns the callback off.

The register/barometer_bricklet/<UID>/altitude() callback is only triggered if the altitude has changed since the last triggering.

request/barometer_bricklet/<UID>/get_altitude_callback_period¶

Request:	empty payload
Response:	period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by request/barometer_bricklet/<UID>/set_altitude_callback_period().

request/barometer_bricklet/<UID>/set_air_pressure_callback_threshold¶

Request:	option – Type: char, Range: See symbols, Default: "x" min – Type: int, Unit: 1/1000 hPa, Range: [-231 to 231 - 1], Default: 0 max – Type: int, Unit: 1/1000 hPa, Range: [-231 to 231 - 1], Default: 0
Response:	no response

Sets the thresholds for the register/barometer_bricklet/<UID>/air_pressure_reached() callback.

The following options are possible:

Option	Description
'x'	Callback is turned off
'o'	Callback is triggered when the air pressure is outside the min and max values
'i'	Callback is triggered when the air pressure is inside the min and max values
'<'	Callback is triggered when the air pressure is smaller than the min value (max is ignored)
'>'	Callback is triggered when the air pressure is greater than the min value (max is ignored)

The following symbols are available for this function:

For option:

• "off" = "x"

• "outside" = "o"

• "inside" = "i"

• "smaller" = "<"

• "greater" = ">"

request/barometer_bricklet/<UID>/get_air_pressure_callback_threshold¶

Request:	empty payload
Response:	option – Type: char, Range: See symbols, Default: "x" min – Type: int, Unit: 1/1000 hPa, Range: [-231 to 231 - 1], Default: 0 max – Type: int, Unit: 1/1000 hPa, Range: [-231 to 231 - 1], Default: 0

Returns the threshold as set by request/barometer_bricklet/<UID>/set_air_pressure_callback_threshold().

The following symbols are available for this function:

For option:

• "off" = "x"

• "outside" = "o"

• "inside" = "i"

• "smaller" = "<"

• "greater" = ">"

request/barometer_bricklet/<UID>/set_altitude_callback_threshold¶

Request:	option – Type: char, Range: See symbols, Default: "x" min – Type: int, Unit: 1 cm, Range: [-231 to 231 - 1], Default: 0 max – Type: int, Unit: 1 cm, Range: [-231 to 231 - 1], Default: 0
Response:	no response

Sets the thresholds for the register/barometer_bricklet/<UID>/altitude_reached() callback.

The following options are possible:

Option	Description
'x'	Callback is turned off
'o'	Callback is triggered when the altitude is outside the min and max values
'i'	Callback is triggered when the altitude is inside the min and max values
'<'	Callback is triggered when the altitude is smaller than the min value (max is ignored)
'>'	Callback is triggered when the altitude is greater than the min value (max is ignored)

The following symbols are available for this function:

For option:

• "off" = "x"

• "outside" = "o"

• "inside" = "i"

• "smaller" = "<"

• "greater" = ">"

request/barometer_bricklet/<UID>/get_altitude_callback_threshold¶

Request:	empty payload
Response:	option – Type: char, Range: See symbols, Default: "x" min – Type: int, Unit: 1 cm, Range: [-231 to 231 - 1], Default: 0 max – Type: int, Unit: 1 cm, Range: [-231 to 231 - 1], Default: 0

Returns the threshold as set by request/barometer_bricklet/<UID>/set_altitude_callback_threshold().

The following symbols are available for this function:

For option:

• "off" = "x"

• "outside" = "o"

• "inside" = "i"

• "smaller" = "<"

• "greater" = ">"

request/barometer_bricklet/<UID>/set_debounce_period¶

Request:	debounce – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100
Response:	no response

Sets the period with which the threshold callbacks

• register/barometer_bricklet/<UID>/air_pressure_reached(),

• register/barometer_bricklet/<UID>/altitude_reached()

are triggered, if the thresholds

• request/barometer_bricklet/<UID>/set_air_pressure_callback_threshold(),

• request/barometer_bricklet/<UID>/set_altitude_callback_threshold()

keep being reached.

request/barometer_bricklet/<UID>/get_debounce_period¶

Request:	empty payload
Response:	debounce – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Returns the debounce period as set by request/barometer_bricklet/<UID>/set_debounce_period().

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the corresponding .../register/... topic and an optional suffix. This suffix can be used to deregister the callback later.

register/barometer_bricklet/<UID>/air_pressure¶

Register Request:	register – Type: bool
Callback Response:	air_pressure – Type: int, Unit: 1/1000 hPa, Range: [10000 to 1200000]

A callback can be registered for this event by publishing to the .../register/barometer_bricklet/<UID>/air_pressure[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/barometer_bricklet/<UID>/air_pressure[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/barometer_bricklet/<UID>/set_air_pressure_callback_period(). The callback payload is the air pressure of the air pressure sensor.

The register/barometer_bricklet/<UID>/air_pressure() callback is only triggered if the air pressure has changed since the last triggering.

register/barometer_bricklet/<UID>/altitude¶

Register Request:	register – Type: bool
Callback Response:	altitude – Type: int, Unit: 1 cm, Range: [-231 to 231 - 1]

A callback can be registered for this event by publishing to the .../register/barometer_bricklet/<UID>/altitude[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/barometer_bricklet/<UID>/altitude[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/barometer_bricklet/<UID>/set_altitude_callback_period(). The callback payload is the altitude of the air pressure sensor.

The register/barometer_bricklet/<UID>/altitude() callback is only triggered if the altitude has changed since the last triggering.

register/barometer_bricklet/<UID>/air_pressure_reached¶

Register Request:	register – Type: bool
Callback Response:	air_pressure – Type: int, Unit: 1/1000 hPa, Range: [10000 to 1200000]

A callback can be registered for this event by publishing to the .../register/barometer_bricklet/<UID>/air_pressure_reached[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/barometer_bricklet/<UID>/air_pressure_reached[/<SUFFIX>] topic for each registered suffix.

This callback is triggered when the threshold as set by request/barometer_bricklet/<UID>/set_air_pressure_callback_threshold() is reached. The callback payload is the air pressure of the air pressure sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by request/barometer_bricklet/<UID>/set_debounce_period().

register/barometer_bricklet/<UID>/altitude_reached¶

Register Request:	register – Type: bool
Callback Response:	altitude – Type: int, Unit: 1 cm, Range: [-231 to 231 - 1]

A callback can be registered for this event by publishing to the .../register/barometer_bricklet/<UID>/altitude_reached[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/barometer_bricklet/<UID>/altitude_reached[/<SUFFIX>] topic for each registered suffix.

This callback is triggered when the threshold as set by request/barometer_bricklet/<UID>/set_altitude_callback_threshold() is reached. The callback payload is the altitude of the air pressure sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by request/barometer_bricklet/<UID>/set_debounce_period().