PHP - Ambient Light Bricklet

This is the API description for the PHP bindings of the Ambient Light Bricklet. General information on what this device does and the technical specifications can be found here.

A tutorial on how to test the Ambient Light Bricklet and get the first examples running can be found here.

Examples

The example code below is public domain.

Simple

Download

<?php

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

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletAmbientLight;

$host = 'localhost';
$port = 4223;
$uid = '7tS'; // Change to your UID

$ipcon = new IPConnection(); // Create IP connection
$al = new BrickletAmbientLight($uid, $ipcon); // Create device object

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

// Get current illuminance (unit is Lux/10)
$illuminance = $al->getIlluminance() / 10.0;

echo "Illuminance: $illuminance Lux\n";

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

?>

Callback

Download

<?php

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

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletAmbientLight;

$host = 'localhost';
$port = 4223;
$uid = '7tS'; // Change to your UID

// Callback function for illuminance callback (parameter has unit Lux/10)
function cb_illuminance($illuminance)
{
    echo "Illuminance: " . $illuminance / 10.0 . " Lux\n";
}

$ipcon = new IPConnection(); // Create IP connection
$al = new BrickletAmbientLight($uid, $ipcon); // Create device object

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

// Set Period for illuminance callback to 1s (1000ms)
// Note: The illuminance callback is only called every second if the
//       illuminance has changed since the last call!
$al->setIlluminanceCallbackPeriod(1000);

// Register illuminance callback to function cb_illuminance
$al->registerCallback(BrickletAmbientLight::CALLBACK_ILLUMINANCE, 'cb_illuminance');

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

?>

Threshold

Download

<?php

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

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletAmbientLight;

$host = 'localhost';
$port = 4223;
$uid = '7tS'; // Change to your UID

// Callback for illuminance greater than 200 Lux
function cb_reached($illuminance)
{
    echo "We have " . $illuminance / 10.0 . " Lux.\n";
    echo "Too bright, close the curtains!\n";
}

$ipcon = new IPConnection(); // Create IP connection
$al = new BrickletAmbientLight($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)
$al->setDebouncePeriod(10000);

// Register threshold reached callback to function cb_reached
$al->registerCallback(BrickletAmbientLight::CALLBACK_ILLUMINANCE_REACHED, 'cb_reached');

// Configure threshold for "greater than 200 Lux" (unit is Lux/10)
$al->setIlluminanceCallbackThreshold('>', 200*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 BrickletAmbientLight(string $uid, IPConnection $ipcon)

Creates an object with the unique device ID $uid:

$ambient_light = new BrickletAmbientLight('YOUR_DEVICE_UID', $ipcon);

This object can then be used after the IP Connection is connected (see examples above).

int BrickletAmbientLight::getIlluminance()

Returns the illuminance of the ambient light sensor. The value has a range of 0 to 9000 and is given in Lux/10, i.e. a value of 4500 means that an illuminance of 450 Lux is measured.

If you want to get the illuminance periodically, it is recommended to use the callback CALLBACK_ILLUMINANCE and set the period with setIlluminanceCallbackPeriod().

Advanced Functions

int BrickletAmbientLight::getAnalogValue()

Returns the value as read by a 12-bit analog-to-digital converter. The value is between 0 and 4095.

Note

The value returned by getIlluminance() is averaged over several samples to yield less noise, while getAnalogValue() gives back raw unfiltered analog values. The only reason to use getAnalogValue() is, if you need the full resolution of the analog-to-digital converter.

Also, the analog-to-digital converter covers three different ranges that are set dynamically depending on the light intensity. It is impossible to distinguish between these ranges with the analog value.

If you want the analog value periodically, it is recommended to use the callback CALLBACK_ANALOG_VALUE and set the period with setAnalogValueCallbackPeriod().

array BrickletAmbientLight::getAPIVersion()

Returns the API version (major, minor, revision) of the bindings for this device.

bool BrickletAmbientLight::getResponseExpected(int $function_id)

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 send and errors are silently ignored, because they cannot be detected.

See setResponseExpected() for the list of function ID constants available for this function.

void BrickletAmbientLight::setResponseExpected(int $function_id, bool $response_expected)

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 and callbacks it is always disabled.

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 send and errors are silently ignored, because they cannot be detected.

The following function ID constants are available for this function:

• BrickletAmbientLight::FUNCTION_SET_ILLUMINANCE_CALLBACK_PERIOD = 3
• BrickletAmbientLight::FUNCTION_SET_ANALOG_VALUE_CALLBACK_PERIOD = 5
• BrickletAmbientLight::FUNCTION_SET_ILLUMINANCE_CALLBACK_THRESHOLD = 7
• BrickletAmbientLight::FUNCTION_SET_ANALOG_VALUE_CALLBACK_THRESHOLD = 9
• BrickletAmbientLight::FUNCTION_SET_DEBOUNCE_PERIOD = 11

void BrickletAmbientLight::setResponseExpectedAll(bool $response_expected)

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

array BrickletAmbientLight::getIdentity()

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 identifiers can be found here.

New in version 2.0.0 (Plugin).

The returned array has the keys uid, connected_uid, position, hardware_version, firmware_version and device_identifier.

Callback Configuration Functions

void BrickletAmbientLight::registerCallback(int $id, callable $callback, mixed $userData=NULL)

Registers a callback with ID $id to the callable $callback. The $userData will be given as a parameter of the callback.

The available IDs with corresponding function signatures are listed below.

void BrickletAmbientLight::setIlluminanceCallbackPeriod(int $period)

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

CALLBACK_ILLUMINANCE is only triggered if the illuminance has changed since the last triggering.

The default value is 0.

int BrickletAmbientLight::getIlluminanceCallbackPeriod()

Returns the period as set by setIlluminanceCallbackPeriod().

void BrickletAmbientLight::setAnalogValueCallbackPeriod(int $period)

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

CALLBACK_ANALOG_VALUE is only triggered if the analog value has changed since the last triggering.

The default value is 0.

int BrickletAmbientLight::getAnalogValueCallbackPeriod()

Returns the period as set by setAnalogValueCallbackPeriod().

void BrickletAmbientLight::setIlluminanceCallbackThreshold(string $option, int $min, int $max)

Sets the thresholds for the CALLBACK_ILLUMINANCE_REACHED callback.

The following options are possible:

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

The default value is (‘x’, 0, 0).

The following constants are available for this function:

• BrickletAmbientLight::THRESHOLD_OPTION_OFF = ‘x’
• BrickletAmbientLight::THRESHOLD_OPTION_OUTSIDE = ‘o’
• BrickletAmbientLight::THRESHOLD_OPTION_INSIDE = ‘i’
• BrickletAmbientLight::THRESHOLD_OPTION_SMALLER = ‘<’
• BrickletAmbientLight::THRESHOLD_OPTION_GREATER = ‘>’

array BrickletAmbientLight::getIlluminanceCallbackThreshold()

Returns the threshold as set by setIlluminanceCallbackThreshold().

The following constants are available for this function:

• BrickletAmbientLight::THRESHOLD_OPTION_OFF = ‘x’
• BrickletAmbientLight::THRESHOLD_OPTION_OUTSIDE = ‘o’
• BrickletAmbientLight::THRESHOLD_OPTION_INSIDE = ‘i’
• BrickletAmbientLight::THRESHOLD_OPTION_SMALLER = ‘<’
• BrickletAmbientLight::THRESHOLD_OPTION_GREATER = ‘>’

The returned array has the keys option, min and max.

void BrickletAmbientLight::setAnalogValueCallbackThreshold(string $option, int $min, int $max)

Sets the thresholds for the CALLBACK_ANALOG_VALUE_REACHED callback.

The following options are possible:

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

The default value is (‘x’, 0, 0).

The following constants are available for this function:

• BrickletAmbientLight::THRESHOLD_OPTION_OFF = ‘x’
• BrickletAmbientLight::THRESHOLD_OPTION_OUTSIDE = ‘o’
• BrickletAmbientLight::THRESHOLD_OPTION_INSIDE = ‘i’
• BrickletAmbientLight::THRESHOLD_OPTION_SMALLER = ‘<’
• BrickletAmbientLight::THRESHOLD_OPTION_GREATER = ‘>’

array BrickletAmbientLight::getAnalogValueCallbackThreshold()

Returns the threshold as set by setAnalogValueCallbackThreshold().

The following constants are available for this function:

• BrickletAmbientLight::THRESHOLD_OPTION_OFF = ‘x’
• BrickletAmbientLight::THRESHOLD_OPTION_OUTSIDE = ‘o’
• BrickletAmbientLight::THRESHOLD_OPTION_INSIDE = ‘i’
• BrickletAmbientLight::THRESHOLD_OPTION_SMALLER = ‘<’
• BrickletAmbientLight::THRESHOLD_OPTION_GREATER = ‘>’

The returned array has the keys option, min and max.

void BrickletAmbientLight::setDebouncePeriod(int $debounce)

Sets the period in ms with which the threshold callbacks

CALLBACK_ILLUMINANCE_REACHED, CALLBACK_ANALOG_VALUE_REACHED

are triggered, if the thresholds

setIlluminanceCallbackThreshold(), setAnalogValueCallbackThreshold()

keep being reached.

The default value is 100.

int BrickletAmbientLight::getDebouncePeriod()

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:

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

$ambient_light->registerCallback(BrickletAmbientLight::CALLBACK_EXAMPLE, 'my_callback');

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 BrickletAmbientLight::CALLBACK_ILLUMINANCE

void callback(int $illuminance [, mixed $userData])

This callback is triggered periodically with the period that is set by setIlluminanceCallbackPeriod(). The parameter is the illuminance of the ambient light sensor.

CALLBACK_ILLUMINANCE is only triggered if the illuminance has changed since the last triggering.

int BrickletAmbientLight::CALLBACK_ANALOG_VALUE

void callback(int $value [, mixed $userData])

This callback is triggered periodically with the period that is set by setAnalogValueCallbackPeriod(). The parameter is the analog value of the ambient light sensor.

CALLBACK_ANALOG_VALUE is only triggered if the analog value has changed since the last triggering.

int BrickletAmbientLight::CALLBACK_ILLUMINANCE_REACHED

void callback(int $illuminance [, mixed $userData])

This callback is triggered when the threshold as set by setIlluminanceCallbackThreshold() is reached. The parameter is the illuminance of the ambient light sensor.

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

int BrickletAmbientLight::CALLBACK_ANALOG_VALUE_REACHED

void callback(int $value [, mixed $userData])

This callback is triggered when the threshold as set by setAnalogValueCallbackThreshold() is reached. The parameter is the analog value of the ambient light sensor.

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

Constants

int BrickletAmbientLight::DEVICE_IDENTIFIER

This constant is used to identify a AmbientLight Bricklet.

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