PHP - PTC Bricklet

This is the description of the PHP API bindings for the PTC Bricklet. General information and technical specifications for the PTC 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)

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<?php

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

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletPTC;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change to your UID

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

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

// Get current temperature (unit is °C/100)
$temperature = $ptc->getTemperature() / 100.0;

echo "Temperature: $temperature °C\n";

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

?>

Callback

Download (ExampleCallback.php)

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<?php

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

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletPTC;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change to your UID

// Callback function for temperature callback (parameter has unit °C/100)
function cb_temperature($temperature)
{
    echo "Temperature: " . $temperature / 100.0 . " °C\n";
}

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

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

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

// Register illuminance callback to function cb_temperature
$ptc->registerCallback(BrickletPTC::CALLBACK_TEMPERATURE, 'cb_temperature');

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

?>

Threshold

Download (ExampleThreshold.php)

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<?php

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

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletPTC;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change to your UID

// Callback for temperature greater than 30 °C
function cb_reached($temperature)
{
    echo "We have " . $temperature / 100.0 . " °C.\n";
    echo "It is too hot, we need air conditioning!\n";
}

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

// Register threshold reached callback to function cb_reached
$ptc->registerCallback(BrickletPTC::CALLBACK_TEMPERATURE_REACHED, 'cb_reached');

// Configure threshold for "greater than 30 °C" (unit is °C/100)
$ptc->setTemperatureCallbackThreshold('>', 30*100, 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 BrickletPTC(string $uid, IPConnection $ipcon)

Creates an object with the unique device ID $uid:

<?php   $ptc = new BrickletPTC('YOUR_DEVICE_UID', $ipcon);   ?>

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

int BrickletPTC::getTemperature()

Returns the temperature of connected sensor. The value has a range of -246 to 849 °C and is given in °C/100, e.g. a value of 4223 means that a temperature of 42.23 °C is measured.

If you want to get the temperature periodically, it is recommended to use the callback CALLBACK_TEMPERATURE and set the period with setTemperatureCallbackPeriod().

bool BrickletPTC::isSensorConnected()

Returns true if the sensor is connected correctly.

If this function returns false, there is either no Pt100 or Pt1000 sensor connected, the sensor is connected incorrectly or the sensor itself is faulty.

void BrickletPTC::setWireMode(int $mode)

Sets the wire mode of the sensor. Possible values are 2, 3 and 4 which correspond to 2-, 3- and 4-wire sensors. The value has to match the jumper configuration on the Bricklet.

The default value is 2 = 2-wire.

The following constants are available for this function:

  • BrickletPTC::WIRE_MODE_2 = 2
  • BrickletPTC::WIRE_MODE_3 = 3
  • BrickletPTC::WIRE_MODE_4 = 4
int BrickletPTC::getWireMode()

Returns the wire mode as set by setWireMode()

The following constants are available for this function:

  • BrickletPTC::WIRE_MODE_2 = 2
  • BrickletPTC::WIRE_MODE_3 = 3
  • BrickletPTC::WIRE_MODE_4 = 4

Advanced Functions

int BrickletPTC::getResistance()

Returns the value as measured by the MAX31865 precision delta-sigma ADC.

The value can be converted with the following formulas:

  • Pt100: resistance = (value * 390) / 32768
  • Pt1000: resistance = (value * 3900) / 32768

If you want to get the resistance periodically, it is recommended to use the callback CALLBACK_RESISTANCE and set the period with setResistanceCallbackPeriod().

void BrickletPTC::setNoiseRejectionFilter(int $filter)

Sets the noise rejection filter to either 50Hz (0) or 60Hz (1). Noise from 50Hz or 60Hz power sources (including harmonics of the AC power's fundamental frequency) is attenuated by 82dB.

Default value is 0 = 50Hz.

The following constants are available for this function:

  • BrickletPTC::FILTER_OPTION_50HZ = 0
  • BrickletPTC::FILTER_OPTION_60HZ = 1
int BrickletPTC::getNoiseRejectionFilter()

Returns the noise rejection filter option as set by setNoiseRejectionFilter()

The following constants are available for this function:

  • BrickletPTC::FILTER_OPTION_50HZ = 0
  • BrickletPTC::FILTER_OPTION_60HZ = 1
array BrickletPTC::getAPIVersion()

Returns the version of the API definition (major, minor, revision) 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 BrickletPTC::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 BrickletPTC::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:

  • BrickletPTC::FUNCTION_SET_TEMPERATURE_CALLBACK_PERIOD = 3
  • BrickletPTC::FUNCTION_SET_RESISTANCE_CALLBACK_PERIOD = 5
  • BrickletPTC::FUNCTION_SET_TEMPERATURE_CALLBACK_THRESHOLD = 7
  • BrickletPTC::FUNCTION_SET_RESISTANCE_CALLBACK_THRESHOLD = 9
  • BrickletPTC::FUNCTION_SET_DEBOUNCE_PERIOD = 11
  • BrickletPTC::FUNCTION_SET_NOISE_REJECTION_FILTER = 17
  • BrickletPTC::FUNCTION_SET_WIRE_MODE = 20
void BrickletPTC::setResponseExpectedAll(bool $response_expected)

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

array BrickletPTC::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 identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

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

Callback Configuration Functions

void BrickletPTC::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 BrickletPTC::setTemperatureCallbackPeriod(int $period)

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

CALLBACK_TEMPERATURE is only triggered if the temperature has changed since the last triggering.

The default value is 0.

int BrickletPTC::getTemperatureCallbackPeriod()

Returns the period as set by setTemperatureCallbackPeriod().

void BrickletPTC::setResistanceCallbackPeriod(int $period)

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

CALLBACK_RESISTANCE is only triggered if the resistance has changed since the last triggering.

The default value is 0.

int BrickletPTC::getResistanceCallbackPeriod()

Returns the period as set by setResistanceCallbackPeriod().

void BrickletPTC::setTemperatureCallbackThreshold(string $option, int $min, int $max)

Sets the thresholds for the CALLBACK_TEMPERATURE_REACHED callback.

The following options are possible:

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

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

The following constants are available for this function:

  • BrickletPTC::THRESHOLD_OPTION_OFF = 'x'
  • BrickletPTC::THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletPTC::THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletPTC::THRESHOLD_OPTION_SMALLER = '<'
  • BrickletPTC::THRESHOLD_OPTION_GREATER = '>'
array BrickletPTC::getTemperatureCallbackThreshold()

Returns the threshold as set by setTemperatureCallbackThreshold().

The following constants are available for this function:

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

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

void BrickletPTC::setResistanceCallbackThreshold(string $option, int $min, int $max)

Sets the thresholds for the CALLBACK_RESISTANCE_REACHED callback.

The following options are possible:

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

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

The following constants are available for this function:

  • BrickletPTC::THRESHOLD_OPTION_OFF = 'x'
  • BrickletPTC::THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletPTC::THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletPTC::THRESHOLD_OPTION_SMALLER = '<'
  • BrickletPTC::THRESHOLD_OPTION_GREATER = '>'
array BrickletPTC::getResistanceCallbackThreshold()

Returns the threshold as set by setResistanceCallbackThreshold().

The following constants are available for this function:

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

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

void BrickletPTC::setDebouncePeriod(int $debounce)

Sets the period in ms with which the threshold callback

is triggered, if the threshold

keeps being reached.

The default value is 100.

int BrickletPTC::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:

<?php

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

$ptc->registerCallback(BrickletPTC::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 BrickletPTC::CALLBACK_TEMPERATURE
<?php   void callback(int $temperature [, mixed $userData])   ?>

This callback is triggered periodically with the period that is set by setTemperatureCallbackPeriod(). The parameter is the temperature of the connected sensor.

CALLBACK_TEMPERATURE is only triggered if the temperature has changed since the last triggering.

int BrickletPTC::CALLBACK_TEMPERATURE_REACHED
<?php   void callback(int $temperature [, mixed $userData])   ?>

This callback is triggered when the threshold as set by setTemperatureCallbackThreshold() is reached. The parameter is the temperature of the connected sensor.

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

int BrickletPTC::CALLBACK_RESISTANCE
<?php   void callback(int $resistance [, mixed $userData])   ?>

This callback is triggered periodically with the period that is set by setResistanceCallbackPeriod(). The parameter is the resistance of the connected sensor.

CALLBACK_RESISTANCE is only triggered if the resistance has changed since the last triggering.

int BrickletPTC::CALLBACK_RESISTANCE_REACHED
<?php   void callback(int $resistance [, mixed $userData])   ?>

This callback is triggered when the threshold as set by setResistanceCallbackThreshold() is reached. The parameter is the resistance of the connected sensor.

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

Constants

int BrickletPTC::DEVICE_IDENTIFIER

This constant is used to identify a PTC 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.

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