Class: Tinkerforge::BrickletSoundPressureLevel

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

Overview

Measures Sound Pressure Level in dB(A/B/C/D/Z)

Constant Summary collapse

DEVICE_IDENTIFIER =

:nodoc:

290
DEVICE_DISPLAY_NAME =

:nodoc:

'Sound Pressure Level Bricklet'
CALLBACK_DECIBEL =

This callback is triggered periodically according to the configuration set by BrickletSoundPressureLevel#set_decibel_callback_configuration.

The parameter is the same as BrickletSoundPressureLevel#get_decibel.

4
CALLBACK_SPECTRUM_LOW_LEVEL =

See CALLBACK_SPECTRUM

8
CALLBACK_SPECTRUM =

This callback is triggered periodically according to the configuration set by BrickletSoundPressureLevel#set_spectrum_callback_configuration.

The parameter is the same as BrickletSoundPressureLevel#get_spectrum.

.. note

If reconstructing the value fails, the callback is triggered with nil for spectrum.

-8
FUNCTION_GET_DECIBEL =

:nodoc:

1
FUNCTION_SET_DECIBEL_CALLBACK_CONFIGURATION =

:nodoc:

2
FUNCTION_GET_DECIBEL_CALLBACK_CONFIGURATION =

:nodoc:

3
FUNCTION_GET_SPECTRUM_LOW_LEVEL =

:nodoc:

5
FUNCTION_SET_SPECTRUM_CALLBACK_CONFIGURATION =

:nodoc:

6
FUNCTION_GET_SPECTRUM_CALLBACK_CONFIGURATION =

:nodoc:

7
FUNCTION_SET_CONFIGURATION =

:nodoc:

9
FUNCTION_GET_CONFIGURATION =

:nodoc:

10
FUNCTION_GET_SPITFP_ERROR_COUNT =

:nodoc:

234
FUNCTION_SET_BOOTLOADER_MODE =

:nodoc:

235
FUNCTION_GET_BOOTLOADER_MODE =

:nodoc:

236
FUNCTION_SET_WRITE_FIRMWARE_POINTER =

:nodoc:

237
FUNCTION_WRITE_FIRMWARE =

:nodoc:

238
FUNCTION_SET_STATUS_LED_CONFIG =

:nodoc:

239
FUNCTION_GET_STATUS_LED_CONFIG =

:nodoc:

240
FUNCTION_GET_CHIP_TEMPERATURE =

:nodoc:

242
FUNCTION_RESET =

:nodoc:

243
FUNCTION_WRITE_UID =

:nodoc:

248
FUNCTION_READ_UID =

:nodoc:

249
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:

'>'
FFT_SIZE_128 =

:nodoc:

0
FFT_SIZE_256 =

:nodoc:

1
FFT_SIZE_512 =

:nodoc:

2
FFT_SIZE_1024 =

:nodoc:

3
WEIGHTING_A =

:nodoc:

0
WEIGHTING_B =

:nodoc:

1
WEIGHTING_C =

:nodoc:

2
WEIGHTING_D =

:nodoc:

3
WEIGHTING_Z =

:nodoc:

4
WEIGHTING_ITU_R_468 =

:nodoc:

5
BOOTLOADER_MODE_BOOTLOADER =

:nodoc:

0
BOOTLOADER_MODE_FIRMWARE =

:nodoc:

1
BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT =

:nodoc:

2
BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT =

:nodoc:

3
BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT =

:nodoc:

4
BOOTLOADER_STATUS_OK =

:nodoc:

0
BOOTLOADER_STATUS_INVALID_MODE =

:nodoc:

1
BOOTLOADER_STATUS_NO_CHANGE =

:nodoc:

2
BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT =

:nodoc:

3
BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT =

:nodoc:

4
BOOTLOADER_STATUS_CRC_MISMATCH =

:nodoc:

5
STATUS_LED_CONFIG_OFF =

:nodoc:

0
STATUS_LED_CONFIG_ON =

:nodoc:

1
STATUS_LED_CONFIG_SHOW_HEARTBEAT =

:nodoc:

2
STATUS_LED_CONFIG_SHOW_STATUS =

: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) ⇒ BrickletSoundPressureLevel

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



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
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 92

def initialize(uid, ipcon)
  super uid, ipcon, DEVICE_IDENTIFIER, DEVICE_DISPLAY_NAME

  @api_version = [2, 0, 0]

  @response_expected[FUNCTION_GET_DECIBEL] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_DECIBEL_CALLBACK_CONFIGURATION] = RESPONSE_EXPECTED_TRUE
  @response_expected[FUNCTION_GET_DECIBEL_CALLBACK_CONFIGURATION] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_GET_SPECTRUM_LOW_LEVEL] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_SPECTRUM_CALLBACK_CONFIGURATION] = RESPONSE_EXPECTED_TRUE
  @response_expected[FUNCTION_GET_SPECTRUM_CALLBACK_CONFIGURATION] = 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_SPITFP_ERROR_COUNT] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_BOOTLOADER_MODE] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_GET_BOOTLOADER_MODE] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_WRITE_FIRMWARE_POINTER] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_WRITE_FIRMWARE] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_SET_STATUS_LED_CONFIG] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_GET_STATUS_LED_CONFIG] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_GET_CHIP_TEMPERATURE] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_RESET] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_WRITE_UID] = RESPONSE_EXPECTED_FALSE
  @response_expected[FUNCTION_READ_UID] = RESPONSE_EXPECTED_ALWAYS_TRUE
  @response_expected[FUNCTION_GET_IDENTITY] = RESPONSE_EXPECTED_ALWAYS_TRUE

  @callback_formats[CALLBACK_DECIBEL] = [10, 'S']
  @callback_formats[CALLBACK_SPECTRUM_LOW_LEVEL] = [72, 'S S S30']

  @high_level_callbacks[CALLBACK_SPECTRUM] = [['stream_length', 'stream_chunk_offset', 'stream_chunk_data'], {'fixed_length' => nil, 'single_chunk' => false}, nil]
  @ipcon.add_device self
end

Instance Method Details

#get_bootloader_mode ⇒ Object

Returns the current bootloader mode, see BrickletSoundPressureLevel#set_bootloader_mode.



290
291
292
293
294
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 290

def get_bootloader_mode
  check_validity

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

#get_chip_temperature ⇒ Object

Returns the temperature as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.



348
349
350
351
352
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 348

def get_chip_temperature
  check_validity

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

#get_configuration ⇒ Object

Returns the configuration as set by BrickletSoundPressureLevel#set_configuration.



251
252
253
254
255
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 251

def get_configuration
  check_validity

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

#get_decibel ⇒ Object

Returns the measured sound pressure in decibels.

The Bricklet supports the weighting standards dB(A), dB(B), dB©, dB(D), dB(Z) and ITU-R 468. You can configure the weighting with BrickletSoundPressureLevel#set_configuration.

By default dB(A) will be used.

If you want to get the value periodically, it is recommended to use the CALLBACK_DECIBEL callback. You can set the callback configuration with BrickletSoundPressureLevel#set_decibel_callback_configuration.



136
137
138
139
140
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 136

def get_decibel
  check_validity

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

#get_decibel_callback_configuration ⇒ Object

Returns the callback configuration as set by BrickletSoundPressureLevel#set_decibel_callback_configuration.



174
175
176
177
178
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 174

def get_decibel_callback_configuration
  check_validity

  send_request FUNCTION_GET_DECIBEL_CALLBACK_CONFIGURATION, [], '', 18, 'L ? 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|



395
396
397
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 395

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

#get_spectrum ⇒ Object

Returns the frequency spectrum. The length of the spectrum is between 512 (FFT size 1024) and 64 (FFT size 128). See BrickletSoundPressureLevel#set_configuration.

Each array element is one bin of the FFT. The first bin is always the DC offset and the other bins have a size between 40Hz (FFT size 1024) and 320Hz (FFT size 128).

In sum the frequency of the spectrum always has a range from 0 to 20480Hz (the FFT is applied to samples with a frequency of 40960Hz).

The returned data is already equalized, which means that the microphone frequency response is compensated and the weighting function is applied (see BrickletSoundPressureLevel#set_configuration for the available weighting standards). Use dB(Z) if you need the unaltered spectrum.

The values are not in dB form yet. If you want a proper dB scale of the spectrum you have to apply the formula f(x) = 20*log10(max(1, x/sqrt(2))) on each value.



417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 417

def get_spectrum
  spectrum_length = nil # assigned in block
  spectrum_data = nil # assigned in block

  @stream_mutex.synchronize {
    ret = get_spectrum_low_level
    spectrum_length = ret[0]
    spectrum_chunk_offset = ret[1]
    spectrum_out_of_sync = spectrum_chunk_offset != 0
    spectrum_data = ret[2]

    while not spectrum_out_of_sync and spectrum_data.length < spectrum_length
      ret = get_spectrum_low_level
      spectrum_length = ret[0]
      spectrum_chunk_offset = ret[1]
      spectrum_out_of_sync = spectrum_chunk_offset != spectrum_data.length
      spectrum_data += ret[2]
    end

    if spectrum_out_of_sync # discard remaining stream to bring it back in-sync
      while spectrum_chunk_offset + 30 < spectrum_length
        ret = get_spectrum_low_level
        spectrum_length = ret[0]
        spectrum_chunk_offset = ret[1]
      end

      raise StreamOutOfSyncException, 'Spectrum stream is out-of-sync'
    end
  }

  spectrum_data[0, spectrum_length]
end

#get_spectrum_callback_configuration ⇒ Object

Returns the callback configuration as set by BrickletSoundPressureLevel#get_spectrum_callback_configuration.



217
218
219
220
221
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 217

def get_spectrum_callback_configuration
  check_validity

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

#get_spectrum_low_level ⇒ Object

Returns the frequency spectrum. The length of the spectrum is between 512 (FFT size 1024) and 64 (FFT size 128). See BrickletSoundPressureLevel#set_configuration.

Each array element is one bin of the FFT. The first bin is always the DC offset and the other bins have a size between 40Hz (FFT size 1024) and 320Hz (FFT size 128).

In sum the frequency of the spectrum always has a range from 0 to 20480Hz (the FFT is applied to samples with a frequency of 40960Hz).

The returned data is already equalized, which means that the microphone frequency response is compensated and the weighting function is applied (see BrickletSoundPressureLevel#set_configuration for the available weighting standards). Use dB(Z) if you need the unaltered spectrum.

The values are not in dB form yet. If you want a proper dB scale of the spectrum you have to apply the formula f(x) = 20*log10(max(1, x/sqrt(2))) on each value.



198
199
200
201
202
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 198

def get_spectrum_low_level
  check_validity

  send_request FUNCTION_GET_SPECTRUM_LOW_LEVEL, [], '', 72, 'S S S30'
end

#get_spitfp_error_count ⇒ Object

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,

  • message checksum errors,

  • framing errors and

  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.



268
269
270
271
272
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 268

def get_spitfp_error_count
  check_validity

  send_request FUNCTION_GET_SPITFP_ERROR_COUNT, [], '', 24, 'L L L L'
end

#get_status_led_config ⇒ Object

Returns the configuration as set by BrickletSoundPressureLevel#set_status_led_config



336
337
338
339
340
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 336

def get_status_led_config
  check_validity

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

#read_uid ⇒ Object

Returns the current UID as an integer. Encode as Base58 to get the usual string version.



379
380
381
382
383
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 379

def read_uid
  check_validity

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

#register_callback(id, &block) ⇒ Object

Registers a callback with ID id to the block block.



451
452
453
454
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 451

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

#reset ⇒ Object

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!



360
361
362
363
364
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 360

def reset
  check_validity

  send_request FUNCTION_RESET, [], '', 8, ''
end

#set_bootloader_mode(mode) ⇒ Object

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.



283
284
285
286
287
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 283

def set_bootloader_mode(mode)
  check_validity

  send_request FUNCTION_SET_BOOTLOADER_MODE, [mode], 'C', 9, 'C'
end

#set_configuration(fft_size, weighting) ⇒ Object

Sets the Sound Pressure Level Bricklet configuration.

With different FFT sizes the Bricklet has a different amount of samples per second and the size of the FFT bins changes. The higher the FFT size the more precise is the result of the dB(X) calculation.

Available FFT sizes are:

  • 1024: 512 bins, 10 samples per second, each bin has size 40Hz

  • 512: 256 bins, 20 samples per second, each bin has size 80Hz

  • 256: 128 bins, 40 samples per second, each bin has size 160Hz

  • 128: 64 bins, 80 samples per second, each bin has size 320Hz

The Bricklet supports different weighting functions. You can choose between dB(A), dB(B), dB©, dB(D), dB(Z) and ITU-R 468.

dB(A/B/C/D) are the standard dB weighting curves. dB(A) is often used to measure volumes at concerts etc. dB(Z) has a flat response, no weighting is applied. ITU-R 468 is an ITU weighting standard mostly used in the UK and Europe.



244
245
246
247
248
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 244

def set_configuration(fft_size, weighting)
  check_validity

  send_request FUNCTION_SET_CONFIGURATION, [fft_size, weighting], 'C C', 8, ''
end

#set_decibel_callback_configuration(period, value_has_to_change, option, min, max) ⇒ Object

The period is the period with which the CALLBACK_DECIBEL callback is triggered periodically. A value of 0 turns the callback off.

If the ‘value has to change`-parameter is set to true, the callback is only triggered after the value has changed. If the value didn’t change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

It is furthermore possible to constrain the callback with thresholds.

The ‘option`-parameter together with min/max sets a threshold for the CALLBACK_DECIBEL callback.

The following options are possible:

"Option", "Description"

"'x'",    "Threshold is turned off"
"'o'",    "Threshold is triggered when the value is *outside* the min and max values"
"'i'",    "Threshold is triggered when the value is *inside* or equal to the min and max values"
"'<'",    "Threshold is triggered when the value is smaller than the min value (max is ignored)"
"'>'",    "Threshold is triggered when the value is greater than the min value (max is ignored)"

If the option is set to ‘x’ (threshold turned off) the callback is triggered with the fixed period.



167
168
169
170
171
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 167

def set_decibel_callback_configuration(period, value_has_to_change, option, min, max)
  check_validity

  send_request FUNCTION_SET_DECIBEL_CALLBACK_CONFIGURATION, [period, value_has_to_change, option, min, max], 'L ? k S S', 8, ''
end

#set_spectrum_callback_configuration(period) ⇒ Object

The period is the period with which the CALLBACK_SPECTRUM callback is triggered periodically. A value of 0 turns the callback off.

Every new measured spectrum will be send at most once. Set the period to 1 to make sure that you get every spectrum.



209
210
211
212
213
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 209

def set_spectrum_callback_configuration(period)
  check_validity

  send_request FUNCTION_SET_SPECTRUM_CALLBACK_CONFIGURATION, [period], 'L', 8, ''
end

#set_status_led_config(config) ⇒ Object

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.



329
330
331
332
333
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 329

def set_status_led_config(config)
  check_validity

  send_request FUNCTION_SET_STATUS_LED_CONFIG, [config], 'C', 8, ''
end

#set_write_firmware_pointer(pointer) ⇒ Object

Sets the firmware pointer for BrickletSoundPressureLevel#write_firmware. The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.



302
303
304
305
306
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 302

def set_write_firmware_pointer(pointer)
  check_validity

  send_request FUNCTION_SET_WRITE_FIRMWARE_POINTER, [pointer], 'L', 8, ''
end

#write_firmware(data) ⇒ Object

Writes 64 Bytes of firmware at the position as written by BrickletSoundPressureLevel#set_write_firmware_pointer before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.



316
317
318
319
320
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 316

def write_firmware(data)
  check_validity

  send_request FUNCTION_WRITE_FIRMWARE, [data], 'C64', 9, 'C'
end

#write_uid(uid) ⇒ Object

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.



371
372
373
374
375
 
# File 'lib/tinkerforge/bricklet_sound_pressure_level.rb', line 371

def write_uid(uid)
  check_validity

  send_request FUNCTION_WRITE_UID, [uid], 'L', 8, ''
end