Modbus - Dust Detector Bricklet – Tinkerforge

- Getting Started
  - Primer
  - Tutorials
  - FAQ
- Hardware
  - Bricks
  - Bricklets
  - Master Extensions
  - Power Supplies
  - Accessories
  - Timeline
- Software
  - Brick Daemon (brickd)
  - Brick Viewer (brickv)
  - API Bindings
  - Firmwares and Plugins
  - Device Identifier
  - Source Code and Bug Tracking
  - Programming Interface
- Starter Kits
  - Weather Station
  - Hardware Hacking
  - Server Room Monitoring
  - Blinkenlights
  - Internet of Things
  - Camera Slider
- Embedded Boards
  - Raspberry Pi
- Specifications
  - Technical Data
  - TCP/IP Protocol
  - Modbus Protocol
  - Wireshark Dissector

# Modbus - Dust Detector Bricklet

Note

This Bricklet is currently in the prototype stage and the software/hardware as well as the documentation is in an incomplete state.

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 -- uint16

  Returns the dust density in µg/m³.

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

### Advanced Functions

`BrickletDustDetector.``set_moving_average`

  Function ID: | 10

  Request:

  - average -- uint8

  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.

  The range for the averaging is 0-100.

  The default value is 100.

`BrickletDustDetector.``get_moving_average`

  Function ID: | 11
  Request: | empty payload

  Response:

  - average -- uint8

  Returns the length moving average as set by `set_moving_average`.

`BrickletDustDetector.``get_identity`

  Function ID: | 255
  Request: | empty payload

  Response:

  - uid -- char[8]
  - connected_uid -- char[8]
  - position -- char
  - hardware_version -- uint8[3]
  - firmware_version -- uint8[3]
  - device_identifier -- uint16

  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' or 'd'.

  The device identifier numbers can be found here.

### Callback Configuration Functions

`BrickletDustDetector.``set_dust_density_callback_period`

  Function ID: | 2

  Request:

  - period -- uint32

  Response: | no response

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

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

  The default value is 0.

`BrickletDustDetector.``get_dust_density_callback_period`

  Function ID: | 3
  Request: | empty payload

  Response:

  - period -- uint32

  Returns the period as set by `set_dust_density_callback_period`.

`BrickletDustDetector.``set_dust_density_callback_threshold`

  Function ID: | 4

  Request:

  - option -- char
  - min -- uint16
  - max -- uint16

  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 default value is ('x', 0, 0).

`BrickletDustDetector.``get_dust_density_callback_threshold`

  Function ID: | 5
  Request: | empty payload

  Response:

  - option -- char
  - min -- uint16
  - max -- uint16

  Returns the threshold as set by `set_dust_density_callback_threshold`.

`BrickletDustDetector.``set_debounce_period`

  Function ID: | 6

  Request:

  - debounce -- uint32

  Response: | no response

  Sets the period in ms with which the threshold callback

  - `CALLBACK_DUST_DENSITY_REACHED`

  is triggered, if the threshold

  - `set_dust_density_callback_threshold`

  keeps being reached.

  The default value is 100.

`BrickletDustDetector.``get_debounce_period`

  Function ID: | 7
  Request: | empty payload

  Response:

  - debounce -- uint32

  Returns the debounce period as set by `set_debounce_period`.

### Callbacks

`BrickletDustDetector.``CALLBACK_DUST_DENSITY`

  Function ID: | 8

  Response:

  - dust_density -- uint16

  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.

  `CALLBACK_DUST_DENSITY` 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 -- uint16

  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`.

The content of this page is licensed under Creative Commons Attribution 3.0 Unported License.