class Tinkerforge::BrickletLaserRangeFinder

Measures distance up to 40m with laser light

Constants

CALLBACK_DISTANCE

This callback is triggered periodically with the period that is set by BrickletLaserRangeFinder#set_distance_callback_period. The parameter is the distance value of the sensor.

The CALLBACK_DISTANCE callback is only triggered if the distance value has changed since the last triggering.

CALLBACK_DISTANCE_REACHED

This callback is triggered when the threshold as set by BrickletLaserRangeFinder#set_distance_callback_threshold is reached. The parameter is the distance value of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by BrickletLaserRangeFinder#set_debounce_period.

CALLBACK_VELOCITY

This callback is triggered periodically with the period that is set by BrickletLaserRangeFinder#set_velocity_callback_period. The parameter is the velocity value of the sensor.

The CALLBACK_VELOCITY callback is only triggered if the velocity has changed since the last triggering.

CALLBACK_VELOCITY_REACHED

This callback is triggered when the threshold as set by BrickletLaserRangeFinder#set_velocity_callback_threshold is reached. The parameter is the velocity value of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by BrickletLaserRangeFinder#set_debounce_period.

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_laser_range_finder.rb, line 90
def initialize(uid, ipcon)
  super uid, ipcon, DEVICE_IDENTIFIER, DEVICE_DISPLAY_NAME

  @api_version = [2, 0, 1]

  @response_expected[FUNCTION_GET_DISTANCE] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_GET_VELOCITY] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_DISTANCE_CALLBACK_PERIOD] = RESPONSE_EXPECTED_TRUE
  @response_expected[FUNCTION_GET_DISTANCE_CALLBACK_PERIOD] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_VELOCITY_CALLBACK_PERIOD] = RESPONSE_EXPECTED_TRUE
  @response_expected[FUNCTION_GET_VELOCITY_CALLBACK_PERIOD] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_DISTANCE_CALLBACK_THRESHOLD] = RESPONSE_EXPECTED_TRUE
  @response_expected[FUNCTION_GET_DISTANCE_CALLBACK_THRESHOLD] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_VELOCITY_CALLBACK_THRESHOLD] = RESPONSE_EXPECTED_TRUE
  @response_expected[FUNCTION_GET_VELOCITY_CALLBACK_THRESHOLD] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_DEBOUNCE_PERIOD] = RESPONSE_EXPECTED_TRUE
  @response_expected[FUNCTION_GET_DEBOUNCE_PERIOD] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_MOVING_AVERAGE] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_GET_MOVING_AVERAGE] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_MODE] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_GET_MODE] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_ENABLE_LASER] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_DISABLE_LASER] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_IS_LASER_ENABLED] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_GET_SENSOR_HARDWARE_VERSION] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_CONFIGURATION] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_GET_CONFIGURATION] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_GET_IDENTITY] = RESPONSE_EXPECTED_ALWAYS_TRUE

  @callback_formats[CALLBACK_DISTANCE] = [10, 'S']
  @callback_formats[CALLBACK_VELOCITY] = [10, 's']
  @callback_formats[CALLBACK_DISTANCE_REACHED] = [10, 'S']
  @callback_formats[CALLBACK_VELOCITY_REACHED] = [10, 's']

  @ipcon.add_device self
end

Public Instance Methods

disable_laser() click to toggle source

Deactivates the laser of the LIDAR.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 329
def disable_laser
  check_validity

  send_request FUNCTION_DISABLE_LASER, [], '', 8, ''
end
enable_laser() click to toggle source

Activates the laser of the LIDAR.

We recommend that you wait 250ms after enabling the laser before the first call of BrickletLaserRangeFinder#get_distance to ensure stable measurements.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 322
def enable_laser
  check_validity

  send_request FUNCTION_ENABLE_LASER, [], '', 8, ''
end
get_configuration() click to toggle source

Returns the configuration as set by BrickletLaserRangeFinder#set_configuration.

.. versionadded

2.0.3$nbsp;(Plugin)

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 391
def get_configuration
  check_validity

  send_request FUNCTION_GET_CONFIGURATION, [], '', 13, 'C ? C S'
end
get_debounce_period() click to toggle source

Returns the debounce period as set by BrickletLaserRangeFinder#set_debounce_period.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 265
def get_debounce_period
  check_validity

  send_request FUNCTION_GET_DEBOUNCE_PERIOD, [], '', 12, 'L'
end
get_distance() click to toggle source

Returns the measured distance.

Sensor hardware version 1 (see BrickletLaserRangeFinder#get_sensor_hardware_version) cannot measure distance and velocity at the same time. Therefore, the distance mode has to be enabled using BrickletLaserRangeFinder#set_mode. Sensor hardware version 3 can measure distance and velocity at the same time. Also the laser has to be enabled, see BrickletLaserRangeFinder#enable_laser.

If you want to get the distance periodically, it is recommended to use the CALLBACK_DISTANCE callback and set the period with BrickletLaserRangeFinder#set_distance_callback_period.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 138
def get_distance
  check_validity

  send_request FUNCTION_GET_DISTANCE, [], '', 10, 'S'
end
get_distance_callback_period() click to toggle source

Returns the period as set by BrickletLaserRangeFinder#set_distance_callback_period.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 175
def get_distance_callback_period
  check_validity

  send_request FUNCTION_GET_DISTANCE_CALLBACK_PERIOD, [], '', 12, 'L'
end
get_distance_callback_threshold() click to toggle source

Returns the threshold as set by BrickletLaserRangeFinder#set_distance_callback_threshold.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 217
def get_distance_callback_threshold
  check_validity

  send_request FUNCTION_GET_DISTANCE_CALLBACK_THRESHOLD, [], '', 13, 'k S S'
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_laser_range_finder.rb, line 407
def get_identity
  send_request FUNCTION_GET_IDENTITY, [], '', 33, 'Z8 Z8 k C3 C3 S'
end
get_mode() click to toggle source

Returns the mode as set by BrickletLaserRangeFinder#set_mode.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 312
def get_mode
  check_validity

  send_request FUNCTION_GET_MODE, [], '', 9, 'C'
end
get_moving_average() click to toggle source

Returns the length moving average as set by BrickletLaserRangeFinder#set_moving_average.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 283
def get_moving_average
  check_validity

  send_request FUNCTION_GET_MOVING_AVERAGE, [], '', 10, 'C C'
end
get_sensor_hardware_version() click to toggle source

Returns the LIDAR-Lite hardware version.

.. versionadded

2.0.3$nbsp;(Plugin)

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 345
def get_sensor_hardware_version
  check_validity

  send_request FUNCTION_GET_SENSOR_HARDWARE_VERSION, [], '', 9, 'C'
end
get_velocity() click to toggle source

Returns the measured velocity.

Sensor hardware version 1 (see BrickletLaserRangeFinder#get_sensor_hardware_version) cannot measure distance and velocity at the same time. Therefore, the velocity mode has to be enabled using BrickletLaserRangeFinder#set_mode. Sensor hardware version 3 can measure distance and velocity at the same time, but the velocity measurement only produces stables results if a fixed measurement rate (see BrickletLaserRangeFinder#set_configuration) is configured. Also the laser has to be enabled, see BrickletLaserRangeFinder#enable_laser.

If you want to get the velocity periodically, it is recommended to use the CALLBACK_VELOCITY callback and set the period with BrickletLaserRangeFinder#set_velocity_callback_period.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 157
def get_velocity
  check_validity

  send_request FUNCTION_GET_VELOCITY, [], '', 10, 's'
end
get_velocity_callback_period() click to toggle source

Returns the period as set by BrickletLaserRangeFinder#set_velocity_callback_period.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 193
def get_velocity_callback_period
  check_validity

  send_request FUNCTION_GET_VELOCITY_CALLBACK_PERIOD, [], '', 12, 'L'
end
get_velocity_callback_threshold() click to toggle source

Returns the threshold as set by BrickletLaserRangeFinder#set_velocity_callback_threshold.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 241
def get_velocity_callback_threshold
  check_validity

  send_request FUNCTION_GET_VELOCITY_CALLBACK_THRESHOLD, [], '', 13, 'k s s'
end
is_laser_enabled() click to toggle source

Returns true if the laser is enabled, false otherwise.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 336
def is_laser_enabled
  check_validity

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

Registers a callback with ID id to the block block.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 412
def register_callback(id, &block)
  callback = block
  @registered_callbacks[id] = callback
end
set_configuration(acquisition_count, enable_quick_termination, threshold_value, measurement_frequency) click to toggle source
.. note

This function is only available if you have a LIDAR-Lite sensor with hardware version 3. Use BrickletLaserRangeFinder#set_mode for hardware version 1. You can check the sensor hardware version using BrickletLaserRangeFinder#get_sensor_hardware_version.

The **Acquisition Count** defines the number of times the Laser Range Finder Bricklet will integrate acquisitions to find a correlation record peak. With a higher count, the Bricklet can measure longer distances. With a lower count, the rate increases. The allowed values are 1-255.

If you set **Enable Quick Termination** to true, the distance measurement will be terminated early if a high peak was already detected. This means that a higher measurement rate can be achieved and long distances can be measured at the same time. However, the chance of false-positive distance measurements increases.

Normally the distance is calculated with a detection algorithm that uses peak value, signal strength and noise. You can however also define a fixed **Threshold Value**. Set this to a low value if you want to measure the distance to something that has very little reflection (e.g. glass) and set it to a high value if you want to measure the distance to something with a very high reflection (e.g. mirror). Set this to 0 to use the default algorithm. The other allowed values are 1-255.

Set the **Measurement Frequency** to force a fixed measurement rate. If set to 0, the Laser Range Finder Bricklet will use the optimal frequency according to the other configurations and the actual measured distance. Since the rate is not fixed in this case, the velocity measurement is not stable. For a stable velocity measurement you should set a fixed measurement frequency. The lower the frequency, the higher is the resolution of the calculated velocity. The allowed values are 10Hz-500Hz (and 0 to turn the fixed frequency off).

.. versionadded

2.0.3$nbsp;(Plugin)

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 382
def set_configuration(acquisition_count, enable_quick_termination, threshold_value, measurement_frequency)
  check_validity

  send_request FUNCTION_SET_CONFIGURATION, [acquisition_count, enable_quick_termination, threshold_value, measurement_frequency], 'C ? C S', 8, ''
end
set_debounce_period(debounce) click to toggle source

Sets the period with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 258
def set_debounce_period(debounce)
  check_validity

  send_request FUNCTION_SET_DEBOUNCE_PERIOD, [debounce], 'L', 8, ''
end
set_distance_callback_period(period) click to toggle source

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

The CALLBACK_DISTANCE callback is only triggered if the distance value has changed since the last triggering.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 168
def set_distance_callback_period(period)
  check_validity

  send_request FUNCTION_SET_DISTANCE_CALLBACK_PERIOD, [period], 'L', 8, ''
end
set_distance_callback_threshold(option, min, max) click to toggle source

Sets the thresholds for the CALLBACK_DISTANCE_REACHED callback.

The following options are possible:

"Option", "Description"

"'x'",    "Callback is turned off"
"'o'",    "Callback is triggered when the distance value is *outside* the min and max values"
"'i'",    "Callback is triggered when the distance value is *inside* the min and max values"
"'<'",    "Callback is triggered when the distance value is smaller than the min value (max is ignored)"
"'>'",    "Callback is triggered when the distance value is greater than the min value (max is ignored)"
# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 210
def set_distance_callback_threshold(option, min, max)
  check_validity

  send_request FUNCTION_SET_DISTANCE_CALLBACK_THRESHOLD, [option, min, max], 'k S S', 8, ''
end
set_mode(mode) click to toggle source
.. note

This function is only available if you have a LIDAR-Lite sensor with hardware version 1. Use BrickletLaserRangeFinder#set_configuration for hardware version 3. You can check the sensor hardware version using BrickletLaserRangeFinder#get_sensor_hardware_version.

The LIDAR-Lite sensor (hardware version 1) has five different modes. One mode is for distance measurements and four modes are for velocity measurements with different ranges.

The following modes are available:

  • 0: Distance is measured with resolution 1.0 cm and range 0-4000 cm

  • 1: Velocity is measured with resolution 0.1 m/s and range is 0-12.7 m/s

  • 2: Velocity is measured with resolution 0.25 m/s and range is 0-31.75 m/s

  • 3: Velocity is measured with resolution 0.5 m/s and range is 0-63.5 m/s

  • 4: Velocity is measured with resolution 1.0 m/s and range is 0-127 m/s

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 305
def set_mode(mode)
  check_validity

  send_request FUNCTION_SET_MODE, [mode], 'C', 8, ''
end
set_velocity_callback_period(period) click to toggle source

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

The CALLBACK_VELOCITY callback is only triggered if the velocity value has changed since the last triggering.

# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 186
def set_velocity_callback_period(period)
  check_validity

  send_request FUNCTION_SET_VELOCITY_CALLBACK_PERIOD, [period], 'L', 8, ''
end
set_velocity_callback_threshold(option, min, max) click to toggle source

Sets the thresholds for the CALLBACK_VELOCITY_REACHED callback.

The following options are possible:

"Option", "Description"

"'x'",    "Callback is turned off"
"'o'",    "Callback is triggered when the velocity is *outside* the min and max values"
"'i'",    "Callback is triggered when the velocity is *inside* the min and max values"
"'<'",    "Callback is triggered when the velocity is smaller than the min value (max is ignored)"
"'>'",    "Callback is triggered when the velocity is greater than the min value (max is ignored)"
# File lib/tinkerforge/bricklet_laser_range_finder.rb, line 234
def set_velocity_callback_threshold(option, min, max)
  check_validity

  send_request FUNCTION_SET_VELOCITY_CALLBACK_THRESHOLD, [option, min, max], 'k s s', 8, ''
end