Software / API Bindings / PHP / API Reference and Examples / Bricklets / Dust Detector Bricklet

PHP - Dust Detector Bricklet¶

This is the description of the PHP 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 PHP API bindings is part of their general description.

Examples¶

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

Simple¶

Download (ExampleSimple.php)

<?php

require_once('Tinkerforge/IPConnection.php');
require_once('Tinkerforge/BrickletDustDetector.php');

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletDustDetector;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change XYZ to the UID of your Dust Detector Bricklet

$ipcon = new IPConnection(); // Create IP connection
$dd = new BrickletDustDetector(UID, $ipcon); // Create device object

$ipcon->connect(HOST, PORT); // Connect to brickd
// Don't use device before ipcon is connected

// Get current dust density
$dust_density = $dd->getDustDensity();
echo "Dust Density: $dust_density µg/m³\n";

echo "Press key to exit\n";
fgetc(fopen('php://stdin', 'r'));
$ipcon->disconnect();

?>

Callback¶

Download (ExampleCallback.php)

<?php

require_once('Tinkerforge/IPConnection.php');
require_once('Tinkerforge/BrickletDustDetector.php');

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletDustDetector;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change XYZ to the UID of your Dust Detector Bricklet

// Callback function for dust density callback
function cb_dustDensity($dust_density)
{
    echo "Dust Density: $dust_density µg/m³\n";
}

$ipcon = new IPConnection(); // Create IP connection
$dd = new BrickletDustDetector(UID, $ipcon); // Create device object

$ipcon->connect(HOST, PORT); // Connect to brickd
// Don't use device before ipcon is connected

// Register dust density callback to function cb_dustDensity
$dd->registerCallback(BrickletDustDetector::CALLBACK_DUST_DENSITY, 'cb_dustDensity');

// 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!
$dd->setDustDensityCallbackPeriod(1000);

echo "Press ctrl+c to exit\n";
$ipcon->dispatchCallbacks(-1); // Dispatch callbacks forever

?>

Threshold¶

Download (ExampleThreshold.php)

<?php

require_once('Tinkerforge/IPConnection.php');
require_once('Tinkerforge/BrickletDustDetector.php');

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletDustDetector;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change XYZ to the UID of your Dust Detector Bricklet

// Callback function for dust density reached callback
function cb_dustDensityReached($dust_density)
{
    echo "Dust Density: $dust_density µg/m³\n";
}

$ipcon = new IPConnection(); // Create IP connection
$dd = new BrickletDustDetector(UID, $ipcon); // Create device object

$ipcon->connect(HOST, PORT); // Connect to brickd
// Don't use device before ipcon is connected

// Get threshold callbacks with a debounce time of 10 seconds (10000ms)
$dd->setDebouncePeriod(10000);

// Register dust density reached callback to function cb_dustDensityReached
$dd->registerCallback(BrickletDustDetector::CALLBACK_DUST_DENSITY_REACHED,
                      'cb_dustDensityReached');

// Configure threshold for dust density "greater than 10 µg/m³"
$dd->setDustDensityCallbackThreshold('>', 10, 0);

echo "Press ctrl+c to exit\n";
$ipcon->dispatchCallbacks(-1); // Dispatch callbacks forever

?>

API¶

Functions that return multiple values return them in an associative array.

Basic Functions¶

class BrickletDustDetector(string $uid, IPConnection $ipcon)¶

Parameters:	$uid – Type: string $ipcon – Type: IPConnection
Returns:	$dust_detector – Type: BrickletDustDetector

Creates an object with the unique device ID $uid:

<?php   $dust_detector = new BrickletDustDetector('YOUR_DEVICE_UID', $ipcon);   ?>

This object can then be used after the IP Connection is connected.

int BrickletDustDetector::getDustDensity()¶

Returns:	$dust_density – Type: int, 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 setDustDensityCallbackPeriod().

Advanced Functions¶

void BrickletDustDetector::setMovingAverage(int $average)¶

Parameters:	$average – Type: int, Range: [0 to 100], Default: 100

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.

int BrickletDustDetector::getMovingAverage()¶

Returns:	$average – Type: int, Range: [0 to 100], Default: 100

Returns the length moving average as set by setMovingAverage().

array BrickletDustDetector::getIdentity()¶

Return Array:

Return Array:	'uid' – Type: string, Length: up to 8 'connected_uid' – Type: string, Length: up to 8 'position' – Type: string, Range: ['a' to 'h', 'z'] 'hardware_version' – Type: array(int, ...), Length: 3 0: $major – Type: int, Range: [0 to 255] 1: $minor – Type: int, Range: [0 to 255] 2: $revision – Type: int, Range: [0 to 255] 'firmware_version' – Type: array(int, ...), Length: 3 0: $major – Type: int, Range: [0 to 255] 1: $minor – Type: int, Range: [0 to 255] 2: $revision – Type: int, Range: [0 to 255] 'device_identifier' – Type: int, Range: [0 to 2¹⁶ - 1]

'uid' – Type: string, Length: up to 8
'connected_uid' – Type: string, Length: up to 8
'position' – Type: string, Range: ['a' to 'h', 'z']
'hardware_version' – Type: array(int, ...), Length: 3

0: $major – Type: int, Range: [0 to 255]
1: $minor – Type: int, Range: [0 to 255]
2: $revision – Type: int, Range: [0 to 255]

'firmware_version' – Type: array(int, ...), Length: 3

0: $major – Type: int, Range: [0 to 255]
1: $minor – Type: int, Range: [0 to 255]
2: $revision – Type: int, Range: [0 to 255]

'device_identifier' – Type: int, 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. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions¶

void BrickletDustDetector::registerCallback(int $callback_id, callable $callback, mixed $user_data=NULL)¶

Parameters:	$callback_id – Type: int $callback – Type: callable $user_data – Type: mixed

Registers the given $function with the given $callback_id. The optional $user_data will be passed as the last parameter to the function.

The available callback IDs with corresponding function signatures are listed below.

void BrickletDustDetector::setDustDensityCallbackPeriod(int $period)¶

Parameters:	$period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0

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.

int BrickletDustDetector::getDustDensityCallbackPeriod()¶

Returns:	$period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0

Returns the period as set by setDustDensityCallbackPeriod().

void BrickletDustDetector::setDustDensityCallbackThreshold(string $option, int $min, int $max)¶

Parameters:	$option – Type: string, Range: See constants, Default: 'x' $min – Type: int, Unit: 1 µg/m³, Range: [0 to 2¹⁶ - 1], Default: 0 $max – Type: int, Unit: 1 µg/m³, Range: [0 to 2¹⁶ - 1], Default: 0

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 constants are available for this function:

For $option:

BrickletDustDetector::THRESHOLD_OPTION_OFF = 'x'
BrickletDustDetector::THRESHOLD_OPTION_OUTSIDE = 'o'
BrickletDustDetector::THRESHOLD_OPTION_INSIDE = 'i'
BrickletDustDetector::THRESHOLD_OPTION_SMALLER = '<'
BrickletDustDetector::THRESHOLD_OPTION_GREATER = '>'

array BrickletDustDetector::getDustDensityCallbackThreshold()¶

Return Array:	'option' – Type: string, Range: See constants, Default: 'x' 'min' – Type: int, Unit: 1 µg/m³, Range: [0 to 2¹⁶ - 1], Default: 0 'max' – Type: int, Unit: 1 µg/m³, Range: [0 to 2¹⁶ - 1], Default: 0

Returns the threshold as set by setDustDensityCallbackThreshold().

The following constants are available for this function:

For $option:

BrickletDustDetector::THRESHOLD_OPTION_OFF = 'x'
BrickletDustDetector::THRESHOLD_OPTION_OUTSIDE = 'o'
BrickletDustDetector::THRESHOLD_OPTION_INSIDE = 'i'
BrickletDustDetector::THRESHOLD_OPTION_SMALLER = '<'
BrickletDustDetector::THRESHOLD_OPTION_GREATER = '>'

void BrickletDustDetector::setDebouncePeriod(int $debounce)¶

Parameters:	$debounce – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 100

Sets the period with which the threshold callback

CALLBACK_DUST_DENSITY_REACHED

is triggered, if the threshold

setDustDensityCallbackThreshold()

keeps being reached.

int BrickletDustDetector::getDebouncePeriod()¶

Returns:	$debounce – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 100

Returns the debounce period as set by setDebouncePeriod().

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the registerCallback() function of the device object. The first parameter is the callback ID and the second parameter the callback function:

<?php

function myCallback($param)
{
    echo $param . "\n";
}

$dust_detector->registerCallback(BrickletDustDetector::CALLBACK_EXAMPLE, 'myCallback');

?>

The available constants with corresponding function signatures 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.

int BrickletDustDetector::CALLBACK_DUST_DENSITY¶

<?php   void callback(int $dust_density [, mixed $user_data])   ?>

Callback Parameters:	$dust_density – Type: int, Unit: 1 µg/m³, Range: [0 to 500] $user_data – Type: mixed

This callback is triggered periodically with the period that is set by setDustDensityCallbackPeriod(). The parameter 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.

int BrickletDustDetector::CALLBACK_DUST_DENSITY_REACHED¶

<?php   void callback(int $dust_density [, mixed $user_data])   ?>

Callback Parameters:	$dust_density – Type: int, Unit: 1 µg/m³, Range: [0 to 500] $user_data – Type: mixed

This callback is triggered when the threshold as set by setDustDensityCallbackThreshold() 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 setDebouncePeriod().

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

array BrickletDustDetector::getAPIVersion()¶

Return Array:	$api_version – Type: array(int, ...), Length: 3 0: $major – Type: int, Range: [0 to 255] 1: $minor – Type: int, Range: [0 to 255] 2: $revision – Type: int, Range: [0 to 255]

Returns the version of the API definition implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

bool BrickletDustDetector::getResponseExpected(int $function_id)¶

Parameters:	$function_id – Type: int, Range: See constants
Returns:	$response_expected – Type: bool

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by setResponseExpected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For $function_id:

BrickletDustDetector::FUNCTION_SET_DUST_DENSITY_CALLBACK_PERIOD = 2
BrickletDustDetector::FUNCTION_SET_DUST_DENSITY_CALLBACK_THRESHOLD = 4
BrickletDustDetector::FUNCTION_SET_DEBOUNCE_PERIOD = 6
BrickletDustDetector::FUNCTION_SET_MOVING_AVERAGE = 10

void BrickletDustDetector::setResponseExpected(int $function_id, bool $response_expected)¶

Parameters:	$function_id – Type: int, Range: See constants $response_expected – Type: bool

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

The following constants are available for this function:

For $function_id:

BrickletDustDetector::FUNCTION_SET_DUST_DENSITY_CALLBACK_PERIOD = 2
BrickletDustDetector::FUNCTION_SET_DUST_DENSITY_CALLBACK_THRESHOLD = 4
BrickletDustDetector::FUNCTION_SET_DEBOUNCE_PERIOD = 6
BrickletDustDetector::FUNCTION_SET_MOVING_AVERAGE = 10

void BrickletDustDetector::setResponseExpectedAll(bool $response_expected)¶

Parameters:	$response_expected – Type: bool

Changes the response expected flag for all setter and callback configuration functions of this device at once.

Constants¶

int BrickletDustDetector::DEVICE_IDENTIFIER¶

This constant is used to identify a Dust Detector Bricklet.

The getIdentity() function and the IPConnection::CALLBACK_ENUMERATE callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

string BrickletDustDetector::DEVICE_DISPLAY_NAME¶: This constant represents the human readable name of a Dust Detector Bricklet.