Shell - Dust Detector Bricklet

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

An installation guide for the Shell API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Simple

Download (example-simple.sh)

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#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this

uid=XYZ # Change XYZ to the UID of your Dust Detector Bricklet

# Get current dust density
tinkerforge call dust-detector-bricklet $uid get-dust-density

Callback

Download (example-callback.sh)

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#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this

uid=XYZ # Change XYZ to the UID of your Dust Detector Bricklet

# Handle incoming dust density callbacks
tinkerforge dispatch dust-detector-bricklet $uid dust-density &

# Set period for dust density callback to 1s (1000ms)
# Note: The dust density callback is only called every second
#       if the dust density has changed since the last call!
tinkerforge call dust-detector-bricklet $uid set-dust-density-callback-period 1000

echo "Press key to exit"; read dummy

kill -- -$$ # Stop callback dispatch in background

Threshold

Download (example-threshold.sh)

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#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this

uid=XYZ # Change XYZ to the UID of your Dust Detector Bricklet

# Get threshold callbacks with a debounce time of 10 seconds (10000ms)
tinkerforge call dust-detector-bricklet $uid set-debounce-period 10000

# Handle incoming dust density reached callbacks
tinkerforge dispatch dust-detector-bricklet $uid dust-density-reached &

# Configure threshold for dust density "greater than 10 µg/m³"
tinkerforge call dust-detector-bricklet $uid set-dust-density-callback-threshold threshold-option-greater 10 0

echo "Press key to exit"; read dummy

kill -- -$$ # Stop callback dispatch in background

API

Possible exit codes for all tinkerforge commands are:

  • 1: interrupted (ctrl+c)
  • 2: syntax error
  • 21: Python 2.5 or newer is required
  • 22: Python argparse module is missing
  • 23: socket error
  • 24: other exception
  • 25: invalid placeholder in format string
  • 26: authentication error
  • 201: timeout occurred
  • 209: invalid argument value
  • 210: function is not supported
  • 211: unknown error

Command Structure

The common options of the call and dispatch commands are documented here. The specific command structure is shown below.

tinkerforge call dust-detector-bricklet [<option>..] <uid> <function> [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The call command is used to call a function of the Dust Detector Bricklet. It can take several options:

  • --help shows help for the specific call command and exits
  • --list-functions shows a list of known functions of the Dust Detector Bricklet and exits
tinkerforge dispatch dust-detector-bricklet [<option>..] <uid> <callback>
Parameters:
  • <uid> -- string
  • <callback> -- string

The dispatch command is used to dispatch a callback of the Dust Detector Bricklet. It can take several options:

  • --help shows help for the specific dispatch command and exits
  • --list-callbacks shows a list of known callbacks of the Dust Detector Bricklet and exits
tinkerforge call dust-detector-bricklet <uid> <function> [<option>..] [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The <function> to be called can take different options depending of its kind. All functions can take the following options:

  • --help shows help for the specific function and exits

Getter functions can take the following options:

  • --execute <command> shell command line to execute for each incoming response (see section about output formatting for details)

Setter functions can take the following options:

  • --expect-response requests response and waits for it

The --expect-response option for setter functions allows to detect timeouts and other error conditions calls of setters as well. The device will then send a response for this purpose. If this option is not given for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

tinkerforge dispatch dust-detector-bricklet <uid> <callback> [<option>..]
Parameters:
  • <uid> -- string
  • <callback> -- string

The <callback> to be dispatched can take several options:

  • --help shows help for the specific callback and exits
  • --execute <command> shell command line to execute for each incoming response (see section about output formatting for details)

Basic Functions

tinkerforge call dust-detector-bricklet <uid> get-dust-density
Output:
  • dust-density -- int

Returns the dust density in µg/m³.

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

Advanced Functions

tinkerforge call dust-detector-bricklet <uid> set-moving-average <average>
Parameters:
  • <average> -- int
Output:

no output

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.

tinkerforge call dust-detector-bricklet <uid> get-moving-average
Output:
  • average -- int

Returns the length moving average as set by set-moving-average.

tinkerforge call dust-detector-bricklet <uid> get-identity
Output:
  • uid -- string
  • connected-uid -- string
  • position -- char
  • hardware-version -- int,int,int
  • firmware-version -- int,int,int
  • device-identifier -- int (has symbols)

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

tinkerforge call dust-detector-bricklet <uid> set-dust-density-callback-period <period>
Parameters:
  • <period> -- int
Output:

no output

Sets the period in ms with which the dust-density callback is triggered periodically. A value of 0 turns the callback off.

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

The default value is 0.

tinkerforge call dust-detector-bricklet <uid> get-dust-density-callback-period
Output:
  • period -- int

Returns the period as set by set-dust-density-callback-period.

tinkerforge call dust-detector-bricklet <uid> set-dust-density-callback-threshold <option> <min> <max>
Parameters:
  • <option> -- char (has symbols)
  • <min> -- int
  • <max> -- int
Output:

no output

Sets the thresholds for the 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).

The following symbols are available for this function:

  • threshold-option-off = x, for <option>
  • threshold-option-outside = o, for <option>
  • threshold-option-inside = i, for <option>
  • threshold-option-smaller = <, for <option>
  • threshold-option-greater = >, for <option>
tinkerforge call dust-detector-bricklet <uid> get-dust-density-callback-threshold
Output:
  • option -- char (has symbols)
  • min -- int
  • max -- int

Returns the threshold as set by set-dust-density-callback-threshold.

The following symbols are available for this function:

  • threshold-option-off = x, for option
  • threshold-option-outside = o, for option
  • threshold-option-inside = i, for option
  • threshold-option-smaller = <, for option
  • threshold-option-greater = >, for option
tinkerforge call dust-detector-bricklet <uid> set-debounce-period <debounce>
Parameters:
  • <debounce> -- int
Output:

no output

Sets the period in ms with which the threshold callback

is triggered, if the threshold

keeps being reached.

The default value is 100.

tinkerforge call dust-detector-bricklet <uid> get-debounce-period
Output:
  • debounce -- int

Returns the debounce period as set by set-debounce-period.

Callbacks

Callbacks can be used to receive time critical or recurring data from the device:

tinkerforge dispatch dust-detector-bricklet <uid> example

The available callbacks are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

tinkerforge dispatch dust-detector-bricklet <uid> dust-density
Output:
  • dust-density -- int

This callback is triggered periodically with the period that is set by set-dust-density-callback-period. The parameter is the dust density of the sensor.

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

tinkerforge dispatch dust-detector-bricklet <uid> dust-density-reached
Output:
  • dust-density -- int

This callback is triggered when the threshold as set by set-dust-density-callback-threshold is reached. The parameter 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.