Ruby - Accelerometer Bricklet

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

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

Examples

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

Simple

Download (example_simple.rb)

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

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_accelerometer'

include Tinkerforge

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

ipcon = IPConnection.new # Create IP connection
a = BrickletAccelerometer.new UID, ipcon # Create device object

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

# Get current acceleration as [x, y, z]
acceleration = a.get_acceleration

puts "Acceleration [X]: #{acceleration[0]/1000.0} g"
puts "Acceleration [Y]: #{acceleration[1]/1000.0} g"
puts "Acceleration [Z]: #{acceleration[2]/1000.0} g"

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_accelerometer'

include Tinkerforge

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

ipcon = IPConnection.new # Create IP connection
a = BrickletAccelerometer.new UID, ipcon # Create device object

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

# Register acceleration callback
a.register_callback(BrickletAccelerometer::CALLBACK_ACCELERATION) do |x, y, z|
  puts "Acceleration [X]: #{x/1000.0} g"
  puts "Acceleration [Y]: #{y/1000.0} g"
  puts "Acceleration [Z]: #{z/1000.0} g"
  puts ''
end

# Set period for acceleration callback to 1s (1000ms)
# Note: The acceleration callback is only called every second
#       if the acceleration has changed since the last call!
a.set_acceleration_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_accelerometer'

include Tinkerforge

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

ipcon = IPConnection.new # Create IP connection
a = BrickletAccelerometer.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)
a.set_debounce_period 10000

# Register acceleration reached callback
a.register_callback(BrickletAccelerometer::CALLBACK_ACCELERATION_REACHED) do |x, y, z|
  puts "Acceleration [X]: #{x/1000.0} g"
  puts "Acceleration [Y]: #{y/1000.0} g"
  puts "Acceleration [Z]: #{z/1000.0} g"
  puts ''
end

# Configure threshold for acceleration "greater than 2 g, 2 g, 2 g"
a.set_acceleration_callback_threshold '>', 2*1000, 0, 2*1000, 0, 2*1000, 0

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

API

All functions listed below are thread-safe.

Basic Functions

BrickletAccelerometer::new(uid, ipcon) → accelerometer
Parameters:
  • uid – Type: str
  • ipcon – Type: IPConnection
Returns:
  • accelerometer – Type: BrickletAccelerometer

Creates an object with the unique device ID uid:

accelerometer = BrickletAccelerometer.new 'YOUR_DEVICE_UID', ipcon

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

BrickletAccelerometer#get_acceleration → [int, int, int]
Return Array:
  • 0: x – Type: int, Unit: 1/1000 gₙ, Range: ?
  • 1: y – Type: int, Unit: 1/1000 gₙ, Range: ?
  • 2: z – Type: int, Unit: 1/1000 gₙ, Range: ?

Returns the acceleration in x, y and z direction. The values are given in gₙ/1000 (1gₙ = 9.80665m/s²). The range is configured with #set_configuration.

If you want to get the acceleration periodically, it is recommended to use the ::CALLBACK_ACCELERATION callback and set the period with #set_acceleration_callback_period.

BrickletAccelerometer#get_temperature → int
Returns:
  • temperature – Type: int, Unit: 1 °C, Range: [-103 to 152]

Returns the temperature of the accelerometer.

BrickletAccelerometer#led_on → nil

Enables the LED on the Bricklet.

BrickletAccelerometer#led_off → nil

Disables the LED on the Bricklet.

BrickletAccelerometer#is_led_on → bool
Returns:
  • on – Type: bool, Default: false

Returns true if the LED is enabled, false otherwise.

Advanced Functions

BrickletAccelerometer#set_configuration(data_rate, full_scale, filter_bandwidth) → nil
Parameters:
  • data_rate – Type: int, Range: See constants, Default: 6
  • full_scale – Type: int, Range: See constants, Default: 1
  • filter_bandwidth – Type: int, Range: See constants, Default: 2

Configures the data rate, full scale range and filter bandwidth. Possible values are:

  • Data rate of 0Hz to 1600Hz.
  • Full scale range of ±2gₙ up to ±16gₙ.
  • Filter bandwidth between 50Hz and 800Hz.

Decreasing data rate or full scale range will also decrease the noise on the data.

The following constants are available for this function:

For data_rate:

  • BrickletAccelerometer::DATA_RATE_OFF = 0
  • BrickletAccelerometer::DATA_RATE_3HZ = 1
  • BrickletAccelerometer::DATA_RATE_6HZ = 2
  • BrickletAccelerometer::DATA_RATE_12HZ = 3
  • BrickletAccelerometer::DATA_RATE_25HZ = 4
  • BrickletAccelerometer::DATA_RATE_50HZ = 5
  • BrickletAccelerometer::DATA_RATE_100HZ = 6
  • BrickletAccelerometer::DATA_RATE_400HZ = 7
  • BrickletAccelerometer::DATA_RATE_800HZ = 8
  • BrickletAccelerometer::DATA_RATE_1600HZ = 9

For full_scale:

  • BrickletAccelerometer::FULL_SCALE_2G = 0
  • BrickletAccelerometer::FULL_SCALE_4G = 1
  • BrickletAccelerometer::FULL_SCALE_6G = 2
  • BrickletAccelerometer::FULL_SCALE_8G = 3
  • BrickletAccelerometer::FULL_SCALE_16G = 4

For filter_bandwidth:

  • BrickletAccelerometer::FILTER_BANDWIDTH_800HZ = 0
  • BrickletAccelerometer::FILTER_BANDWIDTH_400HZ = 1
  • BrickletAccelerometer::FILTER_BANDWIDTH_200HZ = 2
  • BrickletAccelerometer::FILTER_BANDWIDTH_50HZ = 3
BrickletAccelerometer#get_configuration → [int, int, int]
Return Array:
  • 0: data_rate – Type: int, Range: See constants, Default: 6
  • 1: full_scale – Type: int, Range: See constants, Default: 1
  • 2: filter_bandwidth – Type: int, Range: See constants, Default: 2

Returns the configuration as set by #set_configuration.

The following constants are available for this function:

For data_rate:

  • BrickletAccelerometer::DATA_RATE_OFF = 0
  • BrickletAccelerometer::DATA_RATE_3HZ = 1
  • BrickletAccelerometer::DATA_RATE_6HZ = 2
  • BrickletAccelerometer::DATA_RATE_12HZ = 3
  • BrickletAccelerometer::DATA_RATE_25HZ = 4
  • BrickletAccelerometer::DATA_RATE_50HZ = 5
  • BrickletAccelerometer::DATA_RATE_100HZ = 6
  • BrickletAccelerometer::DATA_RATE_400HZ = 7
  • BrickletAccelerometer::DATA_RATE_800HZ = 8
  • BrickletAccelerometer::DATA_RATE_1600HZ = 9

For full_scale:

  • BrickletAccelerometer::FULL_SCALE_2G = 0
  • BrickletAccelerometer::FULL_SCALE_4G = 1
  • BrickletAccelerometer::FULL_SCALE_6G = 2
  • BrickletAccelerometer::FULL_SCALE_8G = 3
  • BrickletAccelerometer::FULL_SCALE_16G = 4

For filter_bandwidth:

  • BrickletAccelerometer::FILTER_BANDWIDTH_800HZ = 0
  • BrickletAccelerometer::FILTER_BANDWIDTH_400HZ = 1
  • BrickletAccelerometer::FILTER_BANDWIDTH_200HZ = 2
  • BrickletAccelerometer::FILTER_BANDWIDTH_50HZ = 3
BrickletAccelerometer#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', 'i', '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). The Raspberry Pi HAT (Zero) Brick is always at position 'i' and the Bricklet connected to an Isolator Bricklet is always as 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

BrickletAccelerometer#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.

BrickletAccelerometer#set_acceleration_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_ACCELERATION callback is triggered periodically. A value of 0 turns the callback off.

The ::CALLBACK_ACCELERATION callback is only triggered if the acceleration has changed since the last triggering.

BrickletAccelerometer#get_acceleration_callback_period → int
Returns:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by #set_acceleration_callback_period.

BrickletAccelerometer#set_acceleration_callback_threshold(option, min_x, max_x, min_y, max_y, min_z, max_z) → nil
Parameters:
  • option – Type: chr, Range: See constants, Default: 'x'
  • min_x – Type: int, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0
  • max_x – Type: int, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0
  • min_y – Type: int, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0
  • max_y – Type: int, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0
  • min_z – Type: int, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0
  • max_z – Type: int, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0

Sets the thresholds for the ::CALLBACK_ACCELERATION_REACHED callback.

The following options are possible:

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

The following constants are available for this function:

For option:

  • BrickletAccelerometer::THRESHOLD_OPTION_OFF = 'x'
  • BrickletAccelerometer::THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletAccelerometer::THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletAccelerometer::THRESHOLD_OPTION_SMALLER = '<'
  • BrickletAccelerometer::THRESHOLD_OPTION_GREATER = '>'
BrickletAccelerometer#get_acceleration_callback_threshold → [chr, int, int, int, int, int, int]
Return Array:
  • 0: option – Type: chr, Range: See constants, Default: 'x'
  • 1: min_x – Type: int, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0
  • 2: max_x – Type: int, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0
  • 3: min_y – Type: int, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0
  • 4: max_y – Type: int, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0
  • 5: min_z – Type: int, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0
  • 6: max_z – Type: int, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0

Returns the threshold as set by #set_acceleration_callback_threshold.

The following constants are available for this function:

For option:

  • BrickletAccelerometer::THRESHOLD_OPTION_OFF = 'x'
  • BrickletAccelerometer::THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletAccelerometer::THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletAccelerometer::THRESHOLD_OPTION_SMALLER = '<'
  • BrickletAccelerometer::THRESHOLD_OPTION_GREATER = '>'
BrickletAccelerometer#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 callback

is triggered, if the threshold

keeps being reached.

BrickletAccelerometer#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:

accelerometer.register_callback BrickletAccelerometer::CALLBACK_EXAMPLE, do |param|
  puts "#{param}"
end

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.

BrickletAccelerometer::CALLBACK_ACCELERATION
Callback Parameters:
  • x – Type: int, Unit: 1/1000 gₙ, Range: ?
  • y – Type: int, Unit: 1/1000 gₙ, Range: ?
  • z – Type: int, Unit: 1/1000 gₙ, Range: ?

This callback is triggered periodically with the period that is set by #set_acceleration_callback_period. The parameters are the X, Y and Z acceleration. The range is configured with #set_configuration.

The ::CALLBACK_ACCELERATION callback is only triggered if the acceleration has changed since the last triggering.

BrickletAccelerometer::CALLBACK_ACCELERATION_REACHED
Callback Parameters:
  • x – Type: int, Unit: 1/1000 gₙ, Range: ?
  • y – Type: int, Unit: 1/1000 gₙ, Range: ?
  • z – Type: int, Unit: 1/1000 gₙ, Range: ?

This callback is triggered when the threshold as set by #set_acceleration_callback_threshold is reached. The parameters are the X, Y and Z acceleration. The range is configured with #set_configuration.

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.

BrickletAccelerometer#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.

BrickletAccelerometer#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 send and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

  • BrickletAccelerometer::FUNCTION_SET_ACCELERATION_CALLBACK_PERIOD = 2
  • BrickletAccelerometer::FUNCTION_SET_ACCELERATION_CALLBACK_THRESHOLD = 4
  • BrickletAccelerometer::FUNCTION_SET_DEBOUNCE_PERIOD = 6
  • BrickletAccelerometer::FUNCTION_SET_CONFIGURATION = 9
  • BrickletAccelerometer::FUNCTION_LED_ON = 11
  • BrickletAccelerometer::FUNCTION_LED_OFF = 12
BrickletAccelerometer#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 send and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

  • BrickletAccelerometer::FUNCTION_SET_ACCELERATION_CALLBACK_PERIOD = 2
  • BrickletAccelerometer::FUNCTION_SET_ACCELERATION_CALLBACK_THRESHOLD = 4
  • BrickletAccelerometer::FUNCTION_SET_DEBOUNCE_PERIOD = 6
  • BrickletAccelerometer::FUNCTION_SET_CONFIGURATION = 9
  • BrickletAccelerometer::FUNCTION_LED_ON = 11
  • BrickletAccelerometer::FUNCTION_LED_OFF = 12
BrickletAccelerometer#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

BrickletAccelerometer::DEVICE_IDENTIFIER

This constant is used to identify a Accelerometer 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.

BrickletAccelerometer::DEVICE_DISPLAY_NAME

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