Class: Tinkerforge::BrickletLaserRangeFinder

Inherits:
Device
  • Object
show all
Defined in:
lib/tinkerforge/bricklet_laser_range_finder.rb

Overview

Measures distance up to 40m with laser light

Constant Summary collapse

DEVICE_IDENTIFIER =

:nodoc:

255
DEVICE_DISPLAY_NAME =

:nodoc:

'Laser Range Finder Bricklet'
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.

20
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.

21
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.

22
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.

23
FUNCTION_GET_DISTANCE =

:nodoc:

1
FUNCTION_GET_VELOCITY =

:nodoc:

2
FUNCTION_SET_DISTANCE_CALLBACK_PERIOD =

:nodoc:

3
FUNCTION_GET_DISTANCE_CALLBACK_PERIOD =

:nodoc:

4
FUNCTION_SET_VELOCITY_CALLBACK_PERIOD =

:nodoc:

5
FUNCTION_GET_VELOCITY_CALLBACK_PERIOD =

:nodoc:

6
FUNCTION_SET_DISTANCE_CALLBACK_THRESHOLD =

:nodoc:

7
FUNCTION_GET_DISTANCE_CALLBACK_THRESHOLD =

:nodoc:

8
FUNCTION_SET_VELOCITY_CALLBACK_THRESHOLD =

:nodoc:

9
FUNCTION_GET_VELOCITY_CALLBACK_THRESHOLD =

:nodoc:

10
FUNCTION_SET_DEBOUNCE_PERIOD =

:nodoc:

11
FUNCTION_GET_DEBOUNCE_PERIOD =

:nodoc:

12
FUNCTION_SET_MOVING_AVERAGE =

:nodoc:

13
FUNCTION_GET_MOVING_AVERAGE =

:nodoc:

14
FUNCTION_SET_MODE =

:nodoc:

15
FUNCTION_GET_MODE =

:nodoc:

16
FUNCTION_ENABLE_LASER =

:nodoc:

17
FUNCTION_DISABLE_LASER =

:nodoc:

18
FUNCTION_IS_LASER_ENABLED =

:nodoc:

19
FUNCTION_GET_SENSOR_HARDWARE_VERSION =

:nodoc:

24
FUNCTION_SET_CONFIGURATION =

:nodoc:

25
FUNCTION_GET_CONFIGURATION =

:nodoc:

26
FUNCTION_GET_IDENTITY =

:nodoc:

255
THRESHOLD_OPTION_OFF =

:nodoc:

'x'
THRESHOLD_OPTION_OUTSIDE =

:nodoc:

'o'
THRESHOLD_OPTION_INSIDE =

:nodoc:

'i'
THRESHOLD_OPTION_SMALLER =

:nodoc:

'<'
THRESHOLD_OPTION_GREATER =

:nodoc:

'>'
MODE_DISTANCE =

:nodoc:

0
MODE_VELOCITY_MAX_13MS =

:nodoc:

1
MODE_VELOCITY_MAX_32MS =

:nodoc:

2
MODE_VELOCITY_MAX_64MS =

:nodoc:

3
MODE_VELOCITY_MAX_127MS =

:nodoc:

4
VERSION_1 =

:nodoc:

1
VERSION_3 =

:nodoc:

3

Constants inherited from Device

Device::DEVICE_IDENTIFIER_CHECK_MATCH, Device::DEVICE_IDENTIFIER_CHECK_MISMATCH, Device::DEVICE_IDENTIFIER_CHECK_PENDING, Device::RESPONSE_EXPECTED_ALWAYS_TRUE, Device::RESPONSE_EXPECTED_FALSE, Device::RESPONSE_EXPECTED_INVALID_FUNCTION_ID, Device::RESPONSE_EXPECTED_TRUE

Instance Attribute Summary

Attributes inherited from Device

#callback_formats, #expected_response_function_id, #expected_response_sequence_number, #high_level_callbacks, #registered_callbacks, #replaced, #uid

Instance Method Summary collapse

Methods inherited from Device

#check_validity, #dequeue_response, #enqueue_response, #get_api_version, #get_response_expected, #send_request, #set_response_expected, #set_response_expected_all

Constructor Details

#initialize(uid, ipcon) ⇒ BrickletLaserRangeFinder

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



91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 91

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

Instance Method Details

#disable_laser ⇒ Object

Deactivates the laser of the LIDAR.



330
331
332
333
334
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 330

def disable_laser
  check_validity

  send_request FUNCTION_DISABLE_LASER, [], '', 8, ''
end

#enable_laser ⇒ Object

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.



323
324
325
326
327
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 323

def enable_laser
  check_validity

  send_request FUNCTION_ENABLE_LASER, [], '', 8, ''
end

#get_configuration ⇒ Object

Returns the configuration as set by BrickletLaserRangeFinder#set_configuration.

.. versionadded

2.0.3$nbsp;(Plugin)



392
393
394
395
396
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 392

def get_configuration
  check_validity

  send_request FUNCTION_GET_CONFIGURATION, [], '', 13, 'C ? C S'
end

#get_debounce_period ⇒ Object

Returns the debounce period as set by BrickletLaserRangeFinder#set_debounce_period.



266
267
268
269
270
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 266

def get_debounce_period
  check_validity

  send_request FUNCTION_GET_DEBOUNCE_PERIOD, [], '', 12, 'L'
end

#get_distance ⇒ Object

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.



139
140
141
142
143
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 139

def get_distance
  check_validity

  send_request FUNCTION_GET_DISTANCE, [], '', 10, 'S'
end

#get_distance_callback_period ⇒ Object

Returns the period as set by BrickletLaserRangeFinder#set_distance_callback_period.



176
177
178
179
180
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 176

def get_distance_callback_period
  check_validity

  send_request FUNCTION_GET_DISTANCE_CALLBACK_PERIOD, [], '', 12, 'L'
end

#get_distance_callback_threshold ⇒ Object

Returns the threshold as set by BrickletLaserRangeFinder#set_distance_callback_threshold.



218
219
220
221
222
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 218

def get_distance_callback_threshold
  check_validity

  send_request FUNCTION_GET_DISTANCE_CALLBACK_THRESHOLD, [], '', 13, 'k S S'
end

#get_identity ⇒ Object

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|



408
409
410
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 408

def get_identity
  send_request FUNCTION_GET_IDENTITY, [], '', 33, 'Z8 Z8 k C3 C3 S'
end

#get_mode ⇒ Object

Returns the mode as set by BrickletLaserRangeFinder#set_mode.



313
314
315
316
317
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 313

def get_mode
  check_validity

  send_request FUNCTION_GET_MODE, [], '', 9, 'C'
end

#get_moving_average ⇒ Object

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



284
285
286
287
288
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 284

def get_moving_average
  check_validity

  send_request FUNCTION_GET_MOVING_AVERAGE, [], '', 10, 'C C'
end

#get_sensor_hardware_version ⇒ Object

Returns the LIDAR-Lite hardware version.

.. versionadded

2.0.3$nbsp;(Plugin)



346
347
348
349
350
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 346

def get_sensor_hardware_version
  check_validity

  send_request FUNCTION_GET_SENSOR_HARDWARE_VERSION, [], '', 9, 'C'
end

#get_velocity ⇒ Object

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.



158
159
160
161
162
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 158

def get_velocity
  check_validity

  send_request FUNCTION_GET_VELOCITY, [], '', 10, 's'
end

#get_velocity_callback_period ⇒ Object

Returns the period as set by BrickletLaserRangeFinder#set_velocity_callback_period.



194
195
196
197
198
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 194

def get_velocity_callback_period
  check_validity

  send_request FUNCTION_GET_VELOCITY_CALLBACK_PERIOD, [], '', 12, 'L'
end

#get_velocity_callback_threshold ⇒ Object

Returns the threshold as set by BrickletLaserRangeFinder#set_velocity_callback_threshold.



242
243
244
245
246
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 242

def get_velocity_callback_threshold
  check_validity

  send_request FUNCTION_GET_VELOCITY_CALLBACK_THRESHOLD, [], '', 13, 'k s s'
end

#is_laser_enabled ⇒ Object

Returns true if the laser is enabled, false otherwise.



337
338
339
340
341
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 337

def is_laser_enabled
  check_validity

  send_request FUNCTION_IS_LASER_ENABLED, [], '', 9, '?'
end

#register_callback(id, &block) ⇒ Object

Registers a callback with ID id to the block block.



413
414
415
416
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 413

def register_callback(id, &block)
  callback = block
  @registered_callbacks[id] = callback
end

#set_configuration(acquisition_count, enable_quick_termination, threshold_value, measurement_frequency) ⇒ Object

.. 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)



383
384
385
386
387
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 383

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) ⇒ Object

Sets the period with which the threshold callbacks

  • CALLBACK_DISTANCE_REACHED,

  • CALLBACK_VELOCITY_REACHED,

are triggered, if the thresholds

  • BrickletLaserRangeFinder#set_distance_callback_threshold,

  • BrickletLaserRangeFinder#set_velocity_callback_threshold,

keep being reached.



259
260
261
262
263
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 259

def set_debounce_period(debounce)
  check_validity

  send_request FUNCTION_SET_DEBOUNCE_PERIOD, [debounce], 'L', 8, ''
end

#set_distance_callback_period(period) ⇒ Object

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.



169
170
171
172
173
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 169

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) ⇒ Object

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)"



211
212
213
214
215
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 211

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) ⇒ Object

.. 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



306
307
308
309
310
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 306

def set_mode(mode)
  check_validity

  send_request FUNCTION_SET_MODE, [mode], 'C', 8, ''
end

#set_moving_average(distance_average_length, velocity_average_length) ⇒ Object

Sets the length of a ‘moving averaging <en.wikipedia.org/wiki/Moving_average>`__ for the distance and velocity.

Setting the length to 0 will turn the averaging completely off. With less averaging, there is more noise on the data.



277
278
279
280
281
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 277

def set_moving_average(distance_average_length, velocity_average_length)
  check_validity

  send_request FUNCTION_SET_MOVING_AVERAGE, [distance_average_length, velocity_average_length], 'C C', 8, ''
end

#set_velocity_callback_period(period) ⇒ Object

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.



187
188
189
190
191
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 187

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) ⇒ Object

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)"



235
236
237
238
239
 
# File 'lib/tinkerforge/bricklet_laser_range_finder.rb', line 235

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