Specifications / Modbus Protocol / API / Bricklets / Dust Detector Bricklet

Modbus - Dust Detector Bricklet¶

This is the description of the Modbus protocol for the Dust Detector Bricklet. General information and technical specifications for the Dust Detector Bricklet are summarized in its hardware description.

API¶

A general description of the Modbus protocol structure can be found here.

Basic Functions¶

BrickletDustDetector.get_dust_density¶

Function ID:	1
Request:	empty payload
Response:	dust_density – Type: uint16, Unit: 1 µg/m³, Range: [0 to 500]

Returns the dust density.

If you want to get the dust density periodically, it is recommended to use the CALLBACK_DUST_DENSITY callback and set the period with set_dust_density_callback_period.

Advanced Functions¶

BrickletDustDetector.set_moving_average¶

Function ID:	10
Request:	average – Type: uint8, Range: [0 to 100], Default: 100
Response:	no response

Sets the length of a moving averaging for the dust density.

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

BrickletDustDetector.get_moving_average¶

Function ID:	11
Request:	empty payload
Response:	average – Type: uint8, Range: [0 to 100], Default: 100

Returns the length moving average as set by set_moving_average.

BrickletDustDetector.get_identity¶

Function ID:	255
Request:	empty payload
Response:	uid – Type: char[8] connected_uid – Type: char[8] position – Type: char, Range: ['a' to 'h', 'z'] hardware_version – Type: uint8[3] 0: major – Type: uint8, Range: [0 to 255] 1: minor – Type: uint8, Range: [0 to 255] 2: revision – Type: uint8, Range: [0 to 255] firmware_version – Type: uint8[3] 0: major – Type: uint8, Range: [0 to 255] 1: minor – Type: uint8, Range: [0 to 255] 2: revision – Type: uint8, Range: [0 to 255] device_identifier – Type: uint16, Range: [0 to 2¹⁶ - 1]

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 Isolator Bricklet is always at position 'z'.

The device identifier numbers can be found here.

Callback Configuration Functions¶

BrickletDustDetector.set_dust_density_callback_period¶

Function ID:	2
Request:	period – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Response:	no response

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

The CALLBACK_DUST_DENSITY callback is only triggered if the dust density has changed since the last triggering.

BrickletDustDetector.get_dust_density_callback_period¶

Function ID:	3
Request:	empty payload
Response:	period – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0

Returns the period as set by set_dust_density_callback_period.

BrickletDustDetector.set_dust_density_callback_threshold¶

Function ID:	4
Request:	option – Type: char, Range: See meanings, Default: 'x' min – Type: uint16, Unit: 1 µg/m³, Range: [0 to 2¹⁶ - 1], Default: 0 max – Type: uint16, Unit: 1 µg/m³, Range: [0 to 2¹⁶ - 1], Default: 0
Response:	no response

Sets the thresholds for the CALLBACK_DUST_DENSITY_REACHED callback.

The following options are possible:

Option	Description
'x'	Callback is turned off
'o'	Callback is triggered when the dust density value is outside the min and max values
'i'	Callback is triggered when the dust density value is inside the min and max values
'<'	Callback is triggered when the dust density value is smaller than the min value (max is ignored)
'>'	Callback is triggered when the dust density value is greater than the min value (max is ignored)

The following meanings are defined for the elements of this function:

For option:

'x' = Off
'o' = Outside
'i' = Inside
'<' = Smaller
'>' = Greater

BrickletDustDetector.get_dust_density_callback_threshold¶

Function ID:	5
Request:	empty payload
Response:	option – Type: char, Range: See meanings, Default: 'x' min – Type: uint16, Unit: 1 µg/m³, Range: [0 to 2¹⁶ - 1], Default: 0 max – Type: uint16, Unit: 1 µg/m³, Range: [0 to 2¹⁶ - 1], Default: 0

Returns the threshold as set by set_dust_density_callback_threshold.

The following meanings are defined for the elements of this function:

For option:

'x' = Off
'o' = Outside
'i' = Inside
'<' = Smaller
'>' = Greater

BrickletDustDetector.set_debounce_period¶

Function ID:	6
Request:	debounce – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 100
Response:	no response

Sets the period with which the threshold callback

CALLBACK_DUST_DENSITY_REACHED

is triggered, if the threshold

set_dust_density_callback_threshold

keeps being reached.

BrickletDustDetector.get_debounce_period¶

Function ID:	7
Request:	empty payload
Response:	debounce – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 100

Returns the debounce period as set by set_debounce_period.

Callbacks¶

BrickletDustDetector.CALLBACK_DUST_DENSITY¶

Function ID:	8
Response:	dust_density – Type: uint16, Unit: 1 µg/m³, Range: [0 to 500]

This callback is triggered periodically with the period that is set by set_dust_density_callback_period. The response value is the dust density of the sensor.

Der CALLBACK_DUST_DENSITY callback is only triggered if the dust density value has changed since the last triggering.

BrickletDustDetector.CALLBACK_DUST_DENSITY_REACHED¶

Function ID:	9
Response:	dust_density – Type: uint16, Unit: 1 µg/m³, Range: [0 to 500]

This callback is triggered when the threshold as set by set_dust_density_callback_threshold is reached. The response value is the dust density of the sensor.

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