Ruby - Dual Button Bricklet

This is the description of the Ruby API bindings for the Dual Button Bricklet. General information and technical specifications for the Dual Button 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).

Callback

Download (example_callback.rb)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
#!/usr/bin/env ruby
# -*- ruby encoding: utf-8 -*-

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_dual_button'

include Tinkerforge

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

ipcon = IPConnection.new # Create IP connection
db = BrickletDualButton.new UID, ipcon # Create device object

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

# Register state changed callback
db.register_callback(BrickletDualButton::CALLBACK_STATE_CHANGED) do |button_l, button_r,
                                                                     led_l, led_r|
  if button_l == BrickletDualButton::BUTTON_STATE_PRESSED
    puts "Left Button: Pressed"
  elsif button_l == BrickletDualButton::BUTTON_STATE_RELEASED
    puts "Left Button: Released"
  end

  if button_r == BrickletDualButton::BUTTON_STATE_PRESSED
    puts "Right Button: Pressed"
  elsif button_r == BrickletDualButton::BUTTON_STATE_RELEASED
    puts "Right Button: Released"
  end

  puts ''
end

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

API

All methods listed below are thread-safe.

Basic Functions

BrickletDualButton::new(uid, ipcon) → dual_button
Parameters:
  • uid -- str
  • ipcon -- IPConnection

Creates an object with the unique device ID uid:

dual_button = BrickletDualButton.new 'YOUR_DEVICE_UID', ipcon

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

BrickletDualButton#set_led_state(led_l, led_r) → nil
Parameters:
  • led_l -- int
  • led_r -- int

Sets the state of the LEDs. Possible states are:

  • 0 = AutoToggleOn: Enables auto toggle with initially enabled LED.
  • 1 = AutoToggleOff: Activates auto toggle with initially disabled LED.
  • 2 = On: Enables LED (auto toggle is disabled).
  • 3 = Off: Disables LED (auto toggle is disabled).

In auto toggle mode the LED is toggled automatically at each press of a button.

If you just want to set one of the LEDs and don't know the current state of the other LED, you can get the state with #get_led_state or you can use #set_selected_led_state.

The default value is (1, 1).

The following constants are available for this function:

  • BrickletDualButton::LED_STATE_AUTO_TOGGLE_ON = 0
  • BrickletDualButton::LED_STATE_AUTO_TOGGLE_OFF = 1
  • BrickletDualButton::LED_STATE_ON = 2
  • BrickletDualButton::LED_STATE_OFF = 3
BrickletDualButton#get_led_state → [int, int]

Returns the current state of the LEDs, as set by #set_led_state.

The following constants are available for this function:

  • BrickletDualButton::LED_STATE_AUTO_TOGGLE_ON = 0
  • BrickletDualButton::LED_STATE_AUTO_TOGGLE_OFF = 1
  • BrickletDualButton::LED_STATE_ON = 2
  • BrickletDualButton::LED_STATE_OFF = 3

The returned array has the values led_l and led_r.

BrickletDualButton#get_button_state → [int, int]

Returns the current state for both buttons. Possible states are:

  • 0 = pressed
  • 1 = released

The following constants are available for this function:

  • BrickletDualButton::BUTTON_STATE_PRESSED = 0
  • BrickletDualButton::BUTTON_STATE_RELEASED = 1

The returned array has the values button_l and button_r.

Advanced Functions

BrickletDualButton#set_selected_led_state(led, state) → nil
Parameters:
  • led -- int
  • state -- int

Sets the state of the selected LED (0 or 1).

The other LED remains untouched.

The following constants are available for this function:

  • BrickletDualButton::LED_LEFT = 0
  • BrickletDualButton::LED_RIGHT = 1
  • BrickletDualButton::LED_STATE_AUTO_TOGGLE_ON = 0
  • BrickletDualButton::LED_STATE_AUTO_TOGGLE_OFF = 1
  • BrickletDualButton::LED_STATE_ON = 2
  • BrickletDualButton::LED_STATE_OFF = 3
BrickletDualButton#get_api_version → [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.

BrickletDualButton#get_response_expected(function_id) → bool
Parameters:function_id -- int

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.

BrickletDualButton#set_response_expected(function_id, response_expected) → nil
Parameters:
  • function_id -- int
  • response_expected -- 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 function ID constants are available for this function:

  • BrickletDualButton::FUNCTION_SET_LED_STATE = 1
  • BrickletDualButton::FUNCTION_SET_SELECTED_LED_STATE = 5
BrickletDualButton#set_response_expected_all(response_expected) → nil
Parameters:response_expected -- bool

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

BrickletDualButton#get_identity → [str, str, str, [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 array has the values uid, connected_uid, position, hardware_version, firmware_version and device_identifier.

Callback Configuration Functions

BrickletDualButton#register_callback(callback_id) { |param [, ...]| block } → nil
Parameters:callback_id -- int

Registers the given block with the given callback_id.

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

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:

dual_button.register_callback BrickletDualButton::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.

BrickletDualButton::CALLBACK_STATE_CHANGED
Parameters:
  • button_l -- int
  • button_r -- int
  • led_l -- int
  • led_r -- int

This callback is called whenever a button is pressed.

Possible states for buttons are:

  • 0 = pressed
  • 1 = released

Possible states for LEDs are:

  • 0 = AutoToggleOn: Auto toggle enabled and LED on.
  • 1 = AutoToggleOff: Auto toggle enabled and LED off.
  • 2 = On: LED on (auto toggle is disabled).
  • 3 = Off: LED off (auto toggle is disabled).

The following constants are available for this function:

  • BrickletDualButton::BUTTON_STATE_PRESSED = 0
  • BrickletDualButton::BUTTON_STATE_RELEASED = 1
  • BrickletDualButton::LED_STATE_AUTO_TOGGLE_ON = 0
  • BrickletDualButton::LED_STATE_AUTO_TOGGLE_OFF = 1
  • BrickletDualButton::LED_STATE_ON = 2
  • BrickletDualButton::LED_STATE_OFF = 3

Constants

BrickletDualButton::DEVICE_IDENTIFIER

This constant is used to identify a Dual Button Bricklet.

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.

BrickletDualButton::DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Dual Button Bricklet.