class Tinkerforge::BrickletMultiTouch

Capacitive touch sensor for 12 electrodes

Constants

CALLBACK_TOUCH_STATE

Returns the current touch state, see BrickletMultiTouch#get_touch_state for information about the state.

This callback is triggered every time the touch state changes.

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_multi_touch.rb, line 36
def initialize(uid, ipcon)
  super uid, ipcon, DEVICE_IDENTIFIER, DEVICE_DISPLAY_NAME

  @api_version = [2, 0, 0]

  @response_expected[FUNCTION_GET_TOUCH_STATE] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_RECALIBRATE] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_SET_ELECTRODE_CONFIG] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_GET_ELECTRODE_CONFIG] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_ELECTRODE_SENSITIVITY] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_GET_ELECTRODE_SENSITIVITY] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_GET_IDENTITY] = RESPONSE_EXPECTED_ALWAYS_TRUE

  @callback_formats[CALLBACK_TOUCH_STATE] = [10, 'S']

  @ipcon.add_device self
end

Public Instance Methods

get_electrode_config() click to toggle source

Returns the electrode configuration, as set by BrickletMultiTouch#set_electrode_config.

# File lib/tinkerforge/bricklet_multi_touch.rb, line 107
def get_electrode_config
  check_validity

  send_request FUNCTION_GET_ELECTRODE_CONFIG, [], '', 10, 'S'
end
get_electrode_sensitivity() click to toggle source

Returns the current sensitivity, as set by BrickletMultiTouch#set_electrode_sensitivity.

# File lib/tinkerforge/bricklet_multi_touch.rb, line 129
def get_electrode_sensitivity
  check_validity

  send_request FUNCTION_GET_ELECTRODE_SENSITIVITY, [], '', 9, 'C'
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_multi_touch.rb, line 145
def get_identity
  send_request FUNCTION_GET_IDENTITY, [], '', 33, 'Z8 Z8 k C3 C3 S'
end
get_touch_state() click to toggle source

Returns the current touch state. The state is given as a bitfield.

Bits 0 to 11 represent the 12 electrodes and bit 12 represents the proximity.

If an electrode is touched, the corresponding bit is true. If a hand or similar is in proximity to the electrodes, bit 12 is true.

Example: The state 4103 = 0x1007 = 0b1000000000111 means that electrodes 0, 1 and 2 are touched and that something is in the proximity of the electrodes.

The proximity is activated with a distance of 1-2cm. An electrode is already counted as touched if a finger is nearly touching the electrode. This means that you can put a piece of paper or foil or similar on top of a electrode to build a touch panel with a professional look.

# File lib/tinkerforge/bricklet_multi_touch.rb, line 72
def get_touch_state
  check_validity

  send_request FUNCTION_GET_TOUCH_STATE, [], '', 10, 'S'
end
recalibrate() click to toggle source

Recalibrates the electrodes. Call this function whenever you changed or moved you electrodes.

# File lib/tinkerforge/bricklet_multi_touch.rb, line 80
def recalibrate
  check_validity

  send_request FUNCTION_RECALIBRATE, [], '', 8, ''
end
register_callback(id, &block) click to toggle source

Registers a callback with ID id to the block block.

# File lib/tinkerforge/bricklet_multi_touch.rb, line 150
def register_callback(id, &block)
  callback = block
  @registered_callbacks[id] = callback
end
set_electrode_config(enabled_electrodes) click to toggle source

Enables/disables electrodes with a bitfield (see BrickletMultiTouch#get_touch_state).

True enables the electrode, false disables the electrode. A disabled electrode will always return false as its state. If you don't need all electrodes you can disable the electrodes that are not needed.

It is recommended that you disable the proximity bit (bit 12) if the proximity feature is not needed. This will reduce the amount of traffic that is produced by the CALLBACK_TOUCH_STATE callback.

Disabling electrodes will also reduce power consumption.

Default: 8191 = 0x1FFF = 0b1111111111111 (all electrodes and proximity feature enabled)

# File lib/tinkerforge/bricklet_multi_touch.rb, line 100
def set_electrode_config(enabled_electrodes)
  check_validity

  send_request FUNCTION_SET_ELECTRODE_CONFIG, [enabled_electrodes], 'S', 8, ''
end
set_electrode_sensitivity(sensitivity) click to toggle source

Sets the sensitivity of the electrodes. An electrode with a high sensitivity will register a touch earlier then an electrode with a low sensitivity.

If you build a big electrode you might need to decrease the sensitivity, since the area that can be charged will get bigger. If you want to be able to activate an electrode from further away you need to increase the sensitivity.

After a new sensitivity is set, you likely want to call BrickletMultiTouch#recalibrate to calibrate the electrodes with the newly defined sensitivity.

# File lib/tinkerforge/bricklet_multi_touch.rb, line 122
def set_electrode_sensitivity(sensitivity)
  check_validity

  send_request FUNCTION_SET_ELECTRODE_SENSITIVITY, [sensitivity], 'C', 8, ''
end