Ruby - Barometer Bricklet¶

Simple¶

Download (example_simple.rb)

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#!/usr/bin/env ruby
# -*- ruby encoding: utf-8 -*-

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_barometer'

include Tinkerforge

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

ipcon = IPConnection.new # Create IP connection
b = BrickletBarometer.new 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
puts "Air Pressure: #{air_pressure/1000.0} hPa"

# Get current altitude
altitude = b.get_altitude
puts "Altitude: #{altitude/100.0} m"

puts 'Press key to exit'
$stdin.gets
ipcon.disconnect

Callback¶

Download (example_callback.rb)

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#!/usr/bin/env ruby
# -*- ruby encoding: utf-8 -*-

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_barometer'

include Tinkerforge

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

ipcon = IPConnection.new # Create IP connection
b = BrickletBarometer.new UID, ipcon # Create device object

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

# Register air pressure callback
b.register_callback(BrickletBarometer::CALLBACK_AIR_PRESSURE) do |air_pressure|
  puts "Air Pressure: #{air_pressure/1000.0} hPa"
end

# Set period for air pressure callback to 1s (1000ms)
# Note: The air pressure callback is only called every second
#       if the air pressure has changed since the last call!
b.set_air_pressure_callback_period 1000

puts 'Press key to exit'
$stdin.gets
ipcon.disconnect

Threshold¶

Download (example_threshold.rb)

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#!/usr/bin/env ruby
# -*- ruby encoding: utf-8 -*-

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_barometer'

include Tinkerforge

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

ipcon = IPConnection.new # Create IP connection
b = BrickletBarometer.new UID, ipcon # Create device object

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

# Get threshold callbacks with a debounce time of 10 seconds (10000ms)
b.set_debounce_period 10000

# Register air pressure reached callback
b.register_callback(BrickletBarometer::CALLBACK_AIR_PRESSURE_REACHED) do |air_pressure|
  puts "Air Pressure: #{air_pressure/1000.0} hPa"
  puts 'Enjoy the potentially good weather!'
end

# Configure threshold for air pressure "greater than 1025 hPa"
b.set_air_pressure_callback_threshold '>', 1025*1000, 0

puts 'Press key to exit'
$stdin.gets
ipcon.disconnect

Basic Functions¶

BrickletBarometer::new(uid, ipcon) → barometer¶

Parameters:	uid – Type: str ipcon – Type: IPConnection
Returns:	barometer – Type: BrickletBarometer

Creates an object with the unique device ID uid:

barometer = BrickletBarometer.new 'YOUR_DEVICE_UID', ipcon

This object can then be used after the IP Connection is connected.

BrickletBarometer#get_air_pressure → int¶

Returns:	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 ::CALLBACK_AIR_PRESSURE callback and set the period with #set_air_pressure_callback_period.

BrickletBarometer#get_altitude → int¶

Returns:	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 #set_reference_air_pressure.

If you want to get the altitude periodically, it is recommended to use the ::CALLBACK_ALTITUDE callback and set the period with #set_altitude_callback_period.

BrickletBarometer#set_reference_air_pressure(air_pressure) → nil¶

Parameters:	air_pressure – Type: int, Unit: 1/1000 hPa, Range: [0, 10000 to 1200000], Default: 1013250

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.

BrickletBarometer#get_reference_air_pressure → int¶

Returns:	air_pressure – Type: int, Unit: 1/1000 hPa, Range: [10000 to 1200000], Default: 1013250

Returns the reference air pressure as set by #set_reference_air_pressure.

Advanced Functions¶

BrickletBarometer#get_chip_temperature → int¶

Returns:	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.

BrickletBarometer#set_averaging(moving_average_pressure, average_pressure, average_temperature) → nil¶

Parameters:	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

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.

New in version 2.0.1 (Plugin).

BrickletBarometer#get_averaging → [int, int, int]¶

Return Array:	0: moving_average_pressure – Type: int, Range: [0 to 25], Default: 25 1: average_pressure – Type: int, Range: [0 to 10], Default: 10 2: average_temperature – Type: int, Range: [0 to 255], Default: 10

Returns the averaging configuration as set by #set_averaging.

New in version 2.0.1 (Plugin).

BrickletBarometer#set_i2c_mode(mode) → nil¶

Parameters:	mode – Type: int, Range: See constants, Default: 0

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 constants are available for this function:

For mode:

• BrickletBarometer::I2C_MODE_FAST = 0
• BrickletBarometer::I2C_MODE_SLOW = 1

New in version 2.0.3 (Plugin).

BrickletBarometer#get_i2c_mode → int¶

Returns:	mode – Type: int, Range: See constants, Default: 0

Returns the I2C mode as set by #set_i2c_mode.

The following constants are available for this function:

For mode:

• BrickletBarometer::I2C_MODE_FAST = 0
• BrickletBarometer::I2C_MODE_SLOW = 1

New in version 2.0.3 (Plugin).

BrickletBarometer#get_identity → [str, str, chr, [int, ...], [int, ...], int]¶

Return Array:

0: uid – Type: str, Length: up to 8 1: connected_uid – Type: str, Length: up to 8 2: position – Type: chr, Range: ['a' to 'h', 'z'] 3: 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] 4: 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] 5: device_identifier – Type: int, Range: [0 to 216 - 1]

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. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions¶

BrickletBarometer#register_callback(callback_id) { |param [, ...]| block } → nil¶

Parameters:	callback_id – Type: int

Registers the given block with the given callback_id.

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

BrickletBarometer#set_air_pressure_callback_period(period) → nil¶

Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Sets the period with which the ::CALLBACK_AIR_PRESSURE callback is triggered periodically. A value of 0 turns the callback off.

The ::CALLBACK_AIR_PRESSURE callback is only triggered if the air pressure has changed since the last triggering.

BrickletBarometer#get_air_pressure_callback_period → int¶

Returns:	period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by #set_air_pressure_callback_period.

BrickletBarometer#set_altitude_callback_period(period) → nil¶

Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Sets the period with which the ::CALLBACK_ALTITUDE callback is triggered periodically. A value of 0 turns the callback off.

The ::CALLBACK_ALTITUDE callback is only triggered if the altitude has changed since the last triggering.

BrickletBarometer#get_altitude_callback_period → int¶

Returns:	period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by #set_altitude_callback_period.

BrickletBarometer#set_air_pressure_callback_threshold(option, min, max) → nil¶

Parameters:	option – Type: chr, Range: See constants, 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

Sets the thresholds for the ::CALLBACK_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 constants are available for this function:

For option:

• BrickletBarometer::THRESHOLD_OPTION_OFF = 'x'
• BrickletBarometer::THRESHOLD_OPTION_OUTSIDE = 'o'
• BrickletBarometer::THRESHOLD_OPTION_INSIDE = 'i'
• BrickletBarometer::THRESHOLD_OPTION_SMALLER = '<'
• BrickletBarometer::THRESHOLD_OPTION_GREATER = '>'

BrickletBarometer#get_air_pressure_callback_threshold → [chr, int, int]¶

Return Array:	0: option – Type: chr, Range: See constants, Default: 'x' 1: min – Type: int, Unit: 1/1000 hPa, Range: [-231 to 231 - 1], Default: 0 2: max – Type: int, Unit: 1/1000 hPa, Range: [-231 to 231 - 1], Default: 0

Returns the threshold as set by #set_air_pressure_callback_threshold.

The following constants are available for this function:

For option:

• BrickletBarometer::THRESHOLD_OPTION_OFF = 'x'
• BrickletBarometer::THRESHOLD_OPTION_OUTSIDE = 'o'
• BrickletBarometer::THRESHOLD_OPTION_INSIDE = 'i'
• BrickletBarometer::THRESHOLD_OPTION_SMALLER = '<'
• BrickletBarometer::THRESHOLD_OPTION_GREATER = '>'

BrickletBarometer#set_altitude_callback_threshold(option, min, max) → nil¶

Parameters:	option – Type: chr, Range: See constants, 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

Sets the thresholds for the ::CALLBACK_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 constants are available for this function:

For option:

• BrickletBarometer::THRESHOLD_OPTION_OFF = 'x'
• BrickletBarometer::THRESHOLD_OPTION_OUTSIDE = 'o'
• BrickletBarometer::THRESHOLD_OPTION_INSIDE = 'i'
• BrickletBarometer::THRESHOLD_OPTION_SMALLER = '<'
• BrickletBarometer::THRESHOLD_OPTION_GREATER = '>'

BrickletBarometer#get_altitude_callback_threshold → [chr, int, int]¶

Return Array:	0: option – Type: chr, Range: See constants, Default: 'x' 1: min – Type: int, Unit: 1 cm, Range: [-231 to 231 - 1], Default: 0 2: max – Type: int, Unit: 1 cm, Range: [-231 to 231 - 1], Default: 0

Returns the threshold as set by #set_altitude_callback_threshold.

The following constants are available for this function:

For option:

• BrickletBarometer::THRESHOLD_OPTION_OFF = 'x'
• BrickletBarometer::THRESHOLD_OPTION_OUTSIDE = 'o'
• BrickletBarometer::THRESHOLD_OPTION_INSIDE = 'i'
• BrickletBarometer::THRESHOLD_OPTION_SMALLER = '<'
• BrickletBarometer::THRESHOLD_OPTION_GREATER = '>'

BrickletBarometer#set_debounce_period(debounce) → nil¶

Parameters:	debounce – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Sets the period with which the threshold callbacks

• ::CALLBACK_AIR_PRESSURE_REACHED,
• ::CALLBACK_ALTITUDE_REACHED

are triggered, if the thresholds

• #set_air_pressure_callback_threshold,
• #set_altitude_callback_threshold

keep being reached.

BrickletBarometer#get_debounce_period → int¶

Returns:	debounce – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Returns the debounce period as set by #set_debounce_period.

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 is a block:

barometer.register_callback BrickletBarometer::CALLBACK_EXAMPLE, do |param|
  puts "#{param}"
end

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

BrickletBarometer::CALLBACK_AIR_PRESSURE¶

Callback Parameters:	air_pressure – Type: int, Unit: 1/1000 hPa, Range: [10000 to 1200000]

This callback is triggered periodically with the period that is set by #set_air_pressure_callback_period. The parameter is the air pressure of the air pressure sensor.

The ::CALLBACK_AIR_PRESSURE callback is only triggered if the air pressure has changed since the last triggering.

BrickletBarometer::CALLBACK_ALTITUDE¶

Callback Parameters:	altitude – Type: int, Unit: 1 cm, Range: [-231 to 231 - 1]

This callback is triggered periodically with the period that is set by #set_altitude_callback_period. The parameter is the altitude of the air pressure sensor.

The ::CALLBACK_ALTITUDE callback is only triggered if the altitude has changed since the last triggering.

BrickletBarometer::CALLBACK_AIR_PRESSURE_REACHED¶

Callback Parameters:	air_pressure – Type: int, Unit: 1/1000 hPa, Range: [10000 to 1200000]

This callback is triggered when the threshold as set by #set_air_pressure_callback_threshold is reached. The parameter 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 #set_debounce_period.

BrickletBarometer::CALLBACK_ALTITUDE_REACHED¶

Callback Parameters:	altitude – Type: int, Unit: 1 cm, Range: [-231 to 231 - 1]

This callback is triggered when the threshold as set by #set_altitude_callback_threshold is reached. The parameter 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 #set_debounce_period.

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

BrickletBarometer#get_api_version → [int, ...]¶

Return Array:	0: api_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]

Returns the version of the API definition 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.

BrickletBarometer#get_response_expected(function_id) → bool¶

Parameters:	function_id – Type: int, Range: See constants
Returns:	response_expected – 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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

• BrickletBarometer::FUNCTION_SET_AIR_PRESSURE_CALLBACK_PERIOD = 3
• BrickletBarometer::FUNCTION_SET_ALTITUDE_CALLBACK_PERIOD = 5
• BrickletBarometer::FUNCTION_SET_AIR_PRESSURE_CALLBACK_THRESHOLD = 7
• BrickletBarometer::FUNCTION_SET_ALTITUDE_CALLBACK_THRESHOLD = 9
• BrickletBarometer::FUNCTION_SET_DEBOUNCE_PERIOD = 11
• BrickletBarometer::FUNCTION_SET_REFERENCE_AIR_PRESSURE = 13
• BrickletBarometer::FUNCTION_SET_AVERAGING = 20
• BrickletBarometer::FUNCTION_SET_I2C_MODE = 22

BrickletBarometer#set_response_expected(function_id, response_expected) → nil¶

Parameters:	function_id – Type: int, Range: See constants response_expected – Type: bool

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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

• BrickletBarometer::FUNCTION_SET_AIR_PRESSURE_CALLBACK_PERIOD = 3
• BrickletBarometer::FUNCTION_SET_ALTITUDE_CALLBACK_PERIOD = 5
• BrickletBarometer::FUNCTION_SET_AIR_PRESSURE_CALLBACK_THRESHOLD = 7
• BrickletBarometer::FUNCTION_SET_ALTITUDE_CALLBACK_THRESHOLD = 9
• BrickletBarometer::FUNCTION_SET_DEBOUNCE_PERIOD = 11
• BrickletBarometer::FUNCTION_SET_REFERENCE_AIR_PRESSURE = 13
• BrickletBarometer::FUNCTION_SET_AVERAGING = 20
• BrickletBarometer::FUNCTION_SET_I2C_MODE = 22

BrickletBarometer#set_response_expected_all(response_expected) → nil¶

Parameters:	response_expected – Type: bool

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

Constants¶

BrickletBarometer::DEVICE_IDENTIFIER¶

This constant is used to identify a Barometer Bricklet.

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

BrickletBarometer::DEVICE_DISPLAY_NAME¶

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