class Tinkerforge::BrickletLCD16x2

16x2 character alphanumeric display with blue backlight

Constants

CALLBACK_BUTTON_PRESSED

This callback is triggered when a button is pressed. The parameter is the number of the button.

CALLBACK_BUTTON_RELEASED

This callback is triggered when a button is released. The parameter is the number of the button.

Public Class Methods

new(uid, ipcon) click to toggle source

Creates an object with the unique device ID uid and adds it to the IP Connection ipcon.

Calls superclass method
# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 42
def initialize(uid, ipcon)
  super uid, ipcon, DEVICE_IDENTIFIER, DEVICE_DISPLAY_NAME

  @api_version = [2, 0, 1]

  @response_expected[FUNCTION_WRITE_LINE] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_CLEAR_DISPLAY] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_BACKLIGHT_ON] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_BACKLIGHT_OFF] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_IS_BACKLIGHT_ON] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_CONFIG] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_GET_CONFIG] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_IS_BUTTON_PRESSED] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_CUSTOM_CHARACTER] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_GET_CUSTOM_CHARACTER] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_GET_IDENTITY] = RESPONSE_EXPECTED_ALWAYS_TRUE

  @callback_formats[CALLBACK_BUTTON_PRESSED] = [9, 'C']
  @callback_formats[CALLBACK_BUTTON_RELEASED] = [9, 'C']

  @ipcon.add_device self
end

Public Instance Methods

backlight_off() click to toggle source

Turns the backlight off.

# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 97
def backlight_off
  check_validity

  send_request FUNCTION_BACKLIGHT_OFF, [], '', 8, ''
end
backlight_on() click to toggle source

Turns the backlight on.

# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 90
def backlight_on
  check_validity

  send_request FUNCTION_BACKLIGHT_ON, [], '', 8, ''
end
clear_display() click to toggle source

Deletes all characters from the display.

# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 83
def clear_display
  check_validity

  send_request FUNCTION_CLEAR_DISPLAY, [], '', 8, ''
end
get_config() click to toggle source

Returns the configuration as set by BrickletLCD16x2#set_config.

# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 121
def get_config
  check_validity

  send_request FUNCTION_GET_CONFIG, [], '', 10, '? ?'
end
get_custom_character(index) click to toggle source

Returns the custom character for a given index, as set with BrickletLCD16x2#set_custom_character.

.. versionadded

2.0.1$nbsp;(Plugin)

# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 172
def get_custom_character(index)
  check_validity

  send_request FUNCTION_GET_CUSTOM_CHARACTER, [index], 'C', 16, 'C8'
end
get_identity() click to toggle source

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 :ref:`Isolator Bricklet <isolator_bricklet>` is always at position 'z'.

The device identifier numbers can be found :ref:`here <device_identifier>`. |device_identifier_constant|

# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 188
def get_identity
  send_request FUNCTION_GET_IDENTITY, [], '', 33, 'Z8 Z8 k C3 C3 S'
end
is_backlight_on() click to toggle source

Returns true if the backlight is on and false otherwise.

# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 104
def is_backlight_on
  check_validity

  send_request FUNCTION_IS_BACKLIGHT_ON, [], '', 9, '?'
end
is_button_pressed(button) click to toggle source

Returns true if the button is pressed.

If you want to react on button presses and releases it is recommended to use the CALLBACK_BUTTON_PRESSED and CALLBACK_BUTTON_RELEASED callbacks.

# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 131
def is_button_pressed(button)
  check_validity

  send_request FUNCTION_IS_BUTTON_PRESSED, [button], 'C', 9, '?'
end
register_callback(id, &block) click to toggle source

Registers a callback with ID id to the block block.

# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 193
def register_callback(id, &block)
  callback = block
  @registered_callbacks[id] = callback
end
set_config(cursor, blinking) click to toggle source

Configures if the cursor (shown as “_”) should be visible and if it should be blinking (shown as a blinking block). The cursor position is one character behind the the last text written with BrickletLCD16x2#write_line.

# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 114
def set_config(cursor, blinking)
  check_validity

  send_request FUNCTION_SET_CONFIG, [cursor, blinking], '? ?', 8, ''
end
set_custom_character(index, character) click to toggle source

The LCD 16x2 Bricklet can store up to 8 custom characters. The characters consist of 5x8 pixels and can be addressed with the index 0-7. To describe the pixels, the first 5 bits of 8 bytes are used. For example, to make a custom character “H”, you should transfer the following:

  • character = 0b00010001“ (decimal value 17)

  • character = 0b00010001“ (decimal value 17)

  • character = 0b00010001“ (decimal value 17)

  • character = 0b00011111“ (decimal value 31)

  • character = 0b00010001“ (decimal value 17)

  • character = 0b00010001“ (decimal value 17)

  • character = 0b00010001“ (decimal value 17)

  • character = 0b00000000“ (decimal value 0)

The characters can later be written with BrickletLCD16x2#write_line by using the characters with the byte representation 8 (“\x08” or “\u0008”) to 15 (“\x0F” or “\u000F”).

You can play around with the custom characters in Brick Viewer since version 2.0.1.

Custom characters are stored by the LCD in RAM, so they have to be set after each startup.

.. versionadded

2.0.1$nbsp;(Plugin)

# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 162
def set_custom_character(index, character)
  check_validity

  send_request FUNCTION_SET_CUSTOM_CHARACTER, [index, character], 'C C8', 8, ''
end
write_line(line, position, text) click to toggle source

Writes text to a specific line with a specific position. The text can have a maximum of 16 characters.

For example: (0, 5, “Hello”) will write Hello in the middle of the first line of the display.

The display uses a special charset that includes all ASCII characters except backslash and tilde. The LCD charset also includes several other non-ASCII characters, see the `charset specification <

# File lib/tinkerforge/bricklet_lcd_16x2.rb, line 76
def write_line(line, position, text)
  check_validity

  send_request FUNCTION_WRITE_LINE, [line, position, text], 'C C Z16', 8, ''
end