Python - Barometer Bricklet 2.0

This is the description of the Python API bindings for the Barometer Bricklet 2.0. General information and technical specifications for the Barometer Bricklet 2.0 are summarized in its hardware description.

An installation guide for the Python API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Simple

Download (example_simple.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Barometer Bricklet 2.0

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_barometer_v2 import BrickletBarometerV2

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    b = BrickletBarometerV2(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Get current air pressure
    air_pressure = b.get_air_pressure()
    print("Air Pressure: " + str(air_pressure/1000.0) + " mbar")

    # Get current altitude
    altitude = b.get_altitude()
    print("Altitude: " + str(altitude/1000.0) + " m")

    raw_input("Press key to exit\n") # Use input() in Python 3
    ipcon.disconnect()

Callback

Download (example_callback.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Barometer Bricklet 2.0

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_barometer_v2 import BrickletBarometerV2

# Callback function for air pressure callback
def cb_air_pressure(air_pressure):
    print("Air Pressure: " + str(air_pressure/1000.0) + " mbar")

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    b = BrickletBarometerV2(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Register air pressure callback to function cb_air_pressure
    b.register_callback(b.CALLBACK_AIR_PRESSURE, cb_air_pressure)

    # Set period for air pressure callback to 1s (1000ms) without a threshold
    b.set_air_pressure_callback_configuration(1000, False, "x", 0, 0)

    raw_input("Press key to exit\n") # Use input() in Python 3
    ipcon.disconnect()

Threshold

Download (example_threshold.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Barometer Bricklet 2.0

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_barometer_v2 import BrickletBarometerV2

# Callback function for air pressure callback
def cb_air_pressure(air_pressure):
    print("Air Pressure: " + str(air_pressure/1000.0) + " mbar")
    print("Enjoy the potentially good weather!")

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    b = BrickletBarometerV2(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Register air pressure callback to function cb_air_pressure
    b.register_callback(b.CALLBACK_AIR_PRESSURE, cb_air_pressure)

    # Configure threshold for air pressure "greater than 1025 mbar"
    # with a debounce period of 1s (1000ms)
    b.set_air_pressure_callback_configuration(1000, False, ">", 1025*1000, 0)

    raw_input("Press key to exit\n") # Use input() in Python 3
    ipcon.disconnect()

API

Generally, every method of the Python bindings can throw an tinkerforge.ip_connection.Error exception that has a value and a description property. value can have different values:

  • Error.TIMEOUT = -1
  • Error.ALREADY_CONNECTED = -7
  • Error.NOT_CONNECTED = -8
  • Error.INVALID_PARAMETER = -9
  • Error.NOT_SUPPORTED = -10
  • Error.UNKNOWN_ERROR_CODE = -11
  • Error.STREAM_OUT_OF_SYNC = -12

All methods listed below are thread-safe.

Basic Functions

BrickletBarometerV2(uid, ipcon)
Parameters:
  • uid -- string
  • ipcon -- IPConnection

Creates an object with the unique device ID uid:

barometer_v2 = BrickletBarometerV2("YOUR_DEVICE_UID", ipcon)

This object can then be used after the IP Connection is connected (see examples above).

BrickletBarometerV2.get_air_pressure()
Return type:int

Returns the measured air pressure. The value has a range of 260000 to 1260000 and is given in mbar/1000, i.e. a value of 1001092 means that an air pressure of 1001.092 mbar is measured.

If you want to get the value periodically, it is recommended to use the CALLBACK_AIR_PRESSURE callback. You can set the callback configuration with set_air_pressure_callback_configuration().

BrickletBarometerV2.get_altitude()
Return type:int

Returns the relative altitude of the air pressure sensor. The value is given in mm and is calculated based on the difference between the current air pressure and the reference air pressure that can be set with set_reference_air_pressure().

If you want to get the value periodically, it is recommended to use the CALLBACK_ALTITUDE callback. You can set the callback configuration with set_altitude_callback_configuration().

BrickletBarometerV2.get_temperature()
Return type:int

Returns the temperature of the air pressure sensor. The value has a range of -4000 to 8500 and is given in °C/100, i.e. a value of 2007 means that a temperature of 20.07 °C is measured.

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 2.0 or the Temperature IR Bricklet 2.0.

If you want to get the value periodically, it is recommended to use the CALLBACK_TEMPERATURE callback. You can set the callback configuration with set_temperature_callback_configuration().

BrickletBarometerV2.set_moving_average_configuration(moving_average_length_air_pressure, moving_average_length_temperature)
Parameters:
  • moving_average_length_air_pressure -- int
  • moving_average_length_temperature -- int
Return type:

None

Sets the length of a moving averaging for the air pressure and temperature measurements.

Setting the length to 1 will turn the averaging off. With less averaging, there is more noise on the data.

The range for the averaging is 1-1000.

If you want to do long term measurements the longest moving average will give the cleanest results.

The default value is 100.

BrickletBarometerV2.get_moving_average_configuration()
Return type:(int, int)

Returns the moving average configuration as set by set_moving_average_configuration().

The returned namedtuple has the variables moving_average_length_air_pressure and moving_average_length_temperature.

BrickletBarometerV2.set_reference_air_pressure(air_pressure)
Parameters:air_pressure -- int
Return type:None

Sets the reference air pressure in mbar/1000 for the altitude calculation. Valid values are between 260000 and 1260000. Setting the reference to the current air pressure results in a calculated altitude of 0mm. 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.

The default value is 1013.25mbar.

BrickletBarometerV2.get_reference_air_pressure()
Return type:int

Returns the reference air pressure as set by set_reference_air_pressure().

Advanced Functions

BrickletBarometerV2.set_calibration(measured_air_pressure, actual_air_pressure)
Parameters:
  • measured_air_pressure -- int
  • actual_air_pressure -- int
Return type:

None

Sets the one point calibration (OPC) values for the air pressure measurement.

Before the Bricklet can be calibrated any previous calibration has to be removed by setting measured air pressure and actual air pressure to 0.

Then the current air pressure has to be measured using the Bricklet (measured air pressure) and with and accurate reference barometer (actual air pressure) at the same time and passed to this function in mbar/1000.

After proper calibration the air pressure measurement can achieve an accuracy up to 0.2 mbar.

The calibration is saved in the EEPROM of the Bricklet and only needs to be configured once.

BrickletBarometerV2.get_calibration()
Return type:(int, int)

Returns the air pressure one point calibration values as set by set_calibration().

The returned namedtuple has the variables measured_air_pressure and actual_air_pressure.

BrickletBarometerV2.set_sensor_configuration(data_rate, air_pressure_low_pass_filter)
Parameters:
  • data_rate -- int
  • air_pressure_low_pass_filter -- int
Return type:

None

Configures the data rate and air pressure low pass filter. The low pass filter cut-off frequency (if enabled) can be set to 1/9th or 1/20th of the configure data rate to decrease the noise on the air pressure data.

The low pass filter configuration only applies to the air pressure measurement. There is no low pass filter for the temperature measurement.

A higher data rate will result in a less precise temperature because of self-heating of the sensor. If the accuracy of the temperature reading is important to you, we would recommend the 1Hz data rate.

The default values are 50Hz data rate and 1/9th low pass filter.

The following constants are available for this function:

  • BrickletBarometerV2.DATA_RATE_OFF = 0
  • BrickletBarometerV2.DATA_RATE_1HZ = 1
  • BrickletBarometerV2.DATA_RATE_10HZ = 2
  • BrickletBarometerV2.DATA_RATE_25HZ = 3
  • BrickletBarometerV2.DATA_RATE_50HZ = 4
  • BrickletBarometerV2.DATA_RATE_75HZ = 5
  • BrickletBarometerV2.LOW_PASS_FILTER_OFF = 0
  • BrickletBarometerV2.LOW_PASS_FILTER_1_9TH = 1
  • BrickletBarometerV2.LOW_PASS_FILTER_1_20TH = 2
BrickletBarometerV2.get_sensor_configuration()
Return type:(int, int)

Returns the sensor configuration as set by set_sensor_configuration().

The following constants are available for this function:

  • BrickletBarometerV2.DATA_RATE_OFF = 0
  • BrickletBarometerV2.DATA_RATE_1HZ = 1
  • BrickletBarometerV2.DATA_RATE_10HZ = 2
  • BrickletBarometerV2.DATA_RATE_25HZ = 3
  • BrickletBarometerV2.DATA_RATE_50HZ = 4
  • BrickletBarometerV2.DATA_RATE_75HZ = 5
  • BrickletBarometerV2.LOW_PASS_FILTER_OFF = 0
  • BrickletBarometerV2.LOW_PASS_FILTER_1_9TH = 1
  • BrickletBarometerV2.LOW_PASS_FILTER_1_20TH = 2

The returned namedtuple has the variables data_rate and air_pressure_low_pass_filter.

BrickletBarometerV2.get_api_version()
Return type:[int, int, int]

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

BrickletBarometerV2.get_response_expected(function_id)
Parameters:function_id -- int
Return type:bool

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by set_response_expected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

See set_response_expected() for the list of function ID constants available for this function.

BrickletBarometerV2.set_response_expected(function_id, response_expected)
Parameters:
  • function_id -- int
  • response_expected -- bool
Return type:

None

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following function ID constants are available for this function:

  • BrickletBarometerV2.FUNCTION_SET_AIR_PRESSURE_CALLBACK_CONFIGURATION = 2
  • BrickletBarometerV2.FUNCTION_SET_ALTITUDE_CALLBACK_CONFIGURATION = 6
  • BrickletBarometerV2.FUNCTION_SET_TEMPERATURE_CALLBACK_CONFIGURATION = 10
  • BrickletBarometerV2.FUNCTION_SET_MOVING_AVERAGE_CONFIGURATION = 13
  • BrickletBarometerV2.FUNCTION_SET_REFERENCE_AIR_PRESSURE = 15
  • BrickletBarometerV2.FUNCTION_SET_CALIBRATION = 17
  • BrickletBarometerV2.FUNCTION_SET_SENSOR_CONFIGURATION = 19
  • BrickletBarometerV2.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletBarometerV2.FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletBarometerV2.FUNCTION_RESET = 243
  • BrickletBarometerV2.FUNCTION_WRITE_UID = 248
BrickletBarometerV2.set_response_expected_all(response_expected)
Parameters:response_expected -- bool
Return type:None

Changes the response expected flag for all setter and callback configuration functions of this device at once.

BrickletBarometerV2.get_spitfp_error_count()
Return type:(int, int, int, int)

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

The returned namedtuple has the variables error_count_ack_checksum, error_count_message_checksum, error_count_frame and error_count_overflow.

BrickletBarometerV2.set_bootloader_mode(mode)
Parameters:mode -- int
Return type:int

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following constants are available for this function:

  • BrickletBarometerV2.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletBarometerV2.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletBarometerV2.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletBarometerV2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletBarometerV2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BrickletBarometerV2.BOOTLOADER_STATUS_OK = 0
  • BrickletBarometerV2.BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickletBarometerV2.BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickletBarometerV2.BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickletBarometerV2.BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickletBarometerV2.BOOTLOADER_STATUS_CRC_MISMATCH = 5
BrickletBarometerV2.get_bootloader_mode()
Return type:int

Returns the current bootloader mode, see set_bootloader_mode().

The following constants are available for this function:

  • BrickletBarometerV2.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletBarometerV2.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletBarometerV2.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletBarometerV2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletBarometerV2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
BrickletBarometerV2.set_write_firmware_pointer(pointer)
Parameters:pointer -- int
Return type:None

Sets the firmware pointer for write_firmware(). The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

BrickletBarometerV2.write_firmware(data)
Parameters:data -- [int, int, ..61x.., int]
Return type:int

Writes 64 Bytes of firmware at the position as written by set_write_firmware_pointer() before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

BrickletBarometerV2.set_status_led_config(config)
Parameters:config -- int
Return type:None

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following constants are available for this function:

  • BrickletBarometerV2.STATUS_LED_CONFIG_OFF = 0
  • BrickletBarometerV2.STATUS_LED_CONFIG_ON = 1
  • BrickletBarometerV2.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletBarometerV2.STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletBarometerV2.get_status_led_config()
Return type:int

Returns the configuration as set by set_status_led_config()

The following constants are available for this function:

  • BrickletBarometerV2.STATUS_LED_CONFIG_OFF = 0
  • BrickletBarometerV2.STATUS_LED_CONFIG_ON = 1
  • BrickletBarometerV2.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletBarometerV2.STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletBarometerV2.get_chip_temperature()
Return type:int

Returns the temperature in °C as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

BrickletBarometerV2.reset()
Return type:None

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

BrickletBarometerV2.write_uid(uid)
Parameters:uid -- int
Return type:None

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

BrickletBarometerV2.read_uid()
Return type:int

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

BrickletBarometerV2.get_identity()
Return type:(str, str, chr, [int, int, int], [int, int, int], int)

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' or 'd'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

The returned namedtuple has the variables uid, connected_uid, position, hardware_version, firmware_version and device_identifier.

Callback Configuration Functions

BrickletBarometerV2.register_callback(callback_id, function)
Parameters:
  • callback_id -- int
  • function -- callable
Return type:

None

Registers the given function with the given callback_id.

The available callback IDs with corresponding function signatures are listed below.

BrickletBarometerV2.set_air_pressure_callback_configuration(period, value_has_to_change, option, min, max)
Parameters:
  • period -- int
  • value_has_to_change -- bool
  • option -- chr
  • min -- int
  • max -- int
Return type:

None

The period in ms is the period with which the CALLBACK_AIR_PRESSURE callback is triggered periodically. A value of 0 turns the callback off.

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the CALLBACK_AIR_PRESSURE callback.

The following options are possible:

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

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The default value is (0, false, 'x', 0, 0).

The following constants are available for this function:

  • BrickletBarometerV2.THRESHOLD_OPTION_OFF = 'x'
  • BrickletBarometerV2.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletBarometerV2.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletBarometerV2.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletBarometerV2.THRESHOLD_OPTION_GREATER = '>'
BrickletBarometerV2.get_air_pressure_callback_configuration()
Return type:(int, bool, chr, int, int)

Returns the callback configuration as set by set_air_pressure_callback_configuration().

The following constants are available for this function:

  • BrickletBarometerV2.THRESHOLD_OPTION_OFF = 'x'
  • BrickletBarometerV2.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletBarometerV2.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletBarometerV2.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletBarometerV2.THRESHOLD_OPTION_GREATER = '>'

The returned namedtuple has the variables period, value_has_to_change, option, min and max.

BrickletBarometerV2.set_altitude_callback_configuration(period, value_has_to_change, option, min, max)
Parameters:
  • period -- int
  • value_has_to_change -- bool
  • option -- chr
  • min -- int
  • max -- int
Return type:

None

The period in ms is the period with which the CALLBACK_ALTITUDE callback is triggered periodically. A value of 0 turns the callback off.

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the CALLBACK_ALTITUDE callback.

The following options are possible:

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

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The default value is (0, false, 'x', 0, 0).

The following constants are available for this function:

  • BrickletBarometerV2.THRESHOLD_OPTION_OFF = 'x'
  • BrickletBarometerV2.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletBarometerV2.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletBarometerV2.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletBarometerV2.THRESHOLD_OPTION_GREATER = '>'
BrickletBarometerV2.get_altitude_callback_configuration()
Return type:(int, bool, chr, int, int)

Returns the callback configuration as set by set_altitude_callback_configuration().

The following constants are available for this function:

  • BrickletBarometerV2.THRESHOLD_OPTION_OFF = 'x'
  • BrickletBarometerV2.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletBarometerV2.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletBarometerV2.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletBarometerV2.THRESHOLD_OPTION_GREATER = '>'

The returned namedtuple has the variables period, value_has_to_change, option, min and max.

BrickletBarometerV2.set_temperature_callback_configuration(period, value_has_to_change, option, min, max)
Parameters:
  • period -- int
  • value_has_to_change -- bool
  • option -- chr
  • min -- int
  • max -- int
Return type:

None

The period in ms is the period with which the CALLBACK_TEMPERATURE callback is triggered periodically. A value of 0 turns the callback off.

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the CALLBACK_TEMPERATURE callback.

The following options are possible:

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

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The default value is (0, false, 'x', 0, 0).

The following constants are available for this function:

  • BrickletBarometerV2.THRESHOLD_OPTION_OFF = 'x'
  • BrickletBarometerV2.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletBarometerV2.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletBarometerV2.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletBarometerV2.THRESHOLD_OPTION_GREATER = '>'
BrickletBarometerV2.get_temperature_callback_configuration()
Return type:(int, bool, chr, int, int)

Returns the callback configuration as set by set_temperature_callback_configuration().

The following constants are available for this function:

  • BrickletBarometerV2.THRESHOLD_OPTION_OFF = 'x'
  • BrickletBarometerV2.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletBarometerV2.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletBarometerV2.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletBarometerV2.THRESHOLD_OPTION_GREATER = '>'

The returned namedtuple has the variables period, value_has_to_change, option, min and max.

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the register_callback() function of the device object. The first parameter is the callback ID and the second parameter the callback function:

def my_callback(param):
    print(param)

barometer_v2.register_callback(BrickletBarometerV2.CALLBACK_EXAMPLE, my_callback)

The available constants with inherent number and type of parameters are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

BrickletBarometerV2.CALLBACK_AIR_PRESSURE
Parameters:air_pressure -- int

This callback is triggered periodically according to the configuration set by set_air_pressure_callback_configuration().

The parameter is the same as get_air_pressure().

BrickletBarometerV2.CALLBACK_ALTITUDE
Parameters:altitude -- int

This callback is triggered periodically according to the configuration set by set_altitude_callback_configuration().

The parameter is the same as get_altitude().

BrickletBarometerV2.CALLBACK_TEMPERATURE
Parameters:temperature -- int

This callback is triggered periodically according to the configuration set by set_temperature_callback_configuration().

The parameter is the same as get_temperature().

Constants

BrickletBarometerV2.DEVICE_IDENTIFIER

This constant is used to identify a Barometer Bricklet 2.0.

The get_identity() function and the CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

BrickletBarometerV2.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Barometer Bricklet 2.0.