PHP - Real-Time Clock Bricklet

This is the description of the PHP API bindings for the Real-Time Clock Bricklet. General information and technical specifications for the Real-Time Clock 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/BrickletRealTimeClock.php');

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletRealTimeClock;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change XYZ to the UID of your Real-Time Clock Bricklet

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

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

// Get current date and time
$date_time = $rtc->getDateTime();

echo "Year: " . $date_time['year'] . "\n";
echo "Month: " . $date_time['month'] . "\n";
echo "Day: " . $date_time['day'] . "\n";
echo "Hour: " . $date_time['hour'] . "\n";
echo "Minute: " . $date_time['minute'] . "\n";
echo "Second: " . $date_time['second'] . "\n";
echo "Centisecond: " . $date_time['centisecond'] . "\n";

if ($date_time['weekday'] == BrickletRealTimeClock::WEEKDAY_MONDAY) {
    echo "Weekday: Monday\n";
} elseif ($date_time['weekday'] == BrickletRealTimeClock::WEEKDAY_TUESDAY) {
    echo "Weekday: Tuesday\n";
} elseif ($date_time['weekday'] == BrickletRealTimeClock::WEEKDAY_WEDNESDAY) {
    echo "Weekday: Wednesday\n";
} elseif ($date_time['weekday'] == BrickletRealTimeClock::WEEKDAY_THURSDAY) {
    echo "Weekday: Thursday\n";
} elseif ($date_time['weekday'] == BrickletRealTimeClock::WEEKDAY_FRIDAY) {
    echo "Weekday: Friday\n";
} elseif ($date_time['weekday'] == BrickletRealTimeClock::WEEKDAY_SATURDAY) {
    echo "Weekday: Saturday\n";
} elseif ($date_time['weekday'] == BrickletRealTimeClock::WEEKDAY_SUNDAY) {
    echo "Weekday: Sunday\n";
}

// Get current timestamp
$timestamp = $rtc->getTimestamp();
echo "Timestamp: $timestamp ms\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/BrickletRealTimeClock.php');

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletRealTimeClock;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change XYZ to the UID of your Real-Time Clock Bricklet

// Callback function for date and time callback
function cb_dateTime($year, $month, $day, $hour, $minute, $second, $centisecond, $weekday,
                     $timestamp)
{
    echo "Year: $year\n";
    echo "Month: $month\n";
    echo "Day: $day\n";
    echo "Hour: $hour\n";
    echo "Minute: $minute\n";
    echo "Second: $second\n";
    echo "Centisecond: $centisecond\n";

    if ($weekday == BrickletRealTimeClock::WEEKDAY_MONDAY) {
        echo "Weekday: Monday\n";
    } elseif ($weekday == BrickletRealTimeClock::WEEKDAY_TUESDAY) {
        echo "Weekday: Tuesday\n";
    } elseif ($weekday == BrickletRealTimeClock::WEEKDAY_WEDNESDAY) {
        echo "Weekday: Wednesday\n";
    } elseif ($weekday == BrickletRealTimeClock::WEEKDAY_THURSDAY) {
        echo "Weekday: Thursday\n";
    } elseif ($weekday == BrickletRealTimeClock::WEEKDAY_FRIDAY) {
        echo "Weekday: Friday\n";
    } elseif ($weekday == BrickletRealTimeClock::WEEKDAY_SATURDAY) {
        echo "Weekday: Saturday\n";
    } elseif ($weekday == BrickletRealTimeClock::WEEKDAY_SUNDAY) {
        echo "Weekday: Sunday\n";
    }

    echo "Timestamp: $timestamp\n";
    echo "\n";
}

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

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

// Register date and time callback to function cb_dateTime
$rtc->registerCallback(BrickletRealTimeClock::CALLBACK_DATE_TIME, 'cb_dateTime');

// Set period for date and time callback to 5s (5000ms)
// Note: The date and time callback is only called every 5 seconds
//       if the date and time has changed since the last call!
$rtc->setDateTimeCallbackPeriod(5000);

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 BrickletRealTimeClock(string $uid, IPConnection $ipcon)
Parameters:
  • $uid – Type: string
  • $ipcon – Type: IPConnection
Returns:
  • $real_time_clock – Type: BrickletRealTimeClock

Creates an object with the unique device ID $uid:

<?php   $real_time_clock = new BrickletRealTimeClock('YOUR_DEVICE_UID', $ipcon);   ?>

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

void BrickletRealTimeClock::setDateTime(int $year, int $month, int $day, int $hour, int $minute, int $second, int $centisecond, int $weekday)
Parameters:
  • $year – Type: int, Range: [2000 to 2099]
  • $month – Type: int, Range: [1 to 12]
  • $day – Type: int, Range: [1 to 31]
  • $hour – Type: int, Range: [0 to 23]
  • $minute – Type: int, Range: [0 to 59]
  • $second – Type: int, Range: [0 to 59]
  • $centisecond – Type: int, Range: [0 to 99]
  • $weekday – Type: int, Range: See constants

Sets the current date (including weekday) and the current time.

If the backup battery is installed then the real-time clock keeps date and time even if the Bricklet is not powered by a Brick.

The real-time clock handles leap year and inserts the 29th of February accordingly. But leap seconds, time zones and daylight saving time are not handled.

The following constants are available for this function:

For $weekday:

  • BrickletRealTimeClock::WEEKDAY_MONDAY = 1
  • BrickletRealTimeClock::WEEKDAY_TUESDAY = 2
  • BrickletRealTimeClock::WEEKDAY_WEDNESDAY = 3
  • BrickletRealTimeClock::WEEKDAY_THURSDAY = 4
  • BrickletRealTimeClock::WEEKDAY_FRIDAY = 5
  • BrickletRealTimeClock::WEEKDAY_SATURDAY = 6
  • BrickletRealTimeClock::WEEKDAY_SUNDAY = 7
array BrickletRealTimeClock::getDateTime()
Return Array:
  • 'year' – Type: int, Range: [2000 to 2099]
  • 'month' – Type: int, Range: [1 to 12]
  • 'day' – Type: int, Range: [1 to 31]
  • 'hour' – Type: int, Range: [0 to 23]
  • 'minute' – Type: int, Range: [0 to 59]
  • 'second' – Type: int, Range: [0 to 59]
  • 'centisecond' – Type: int, Range: [0 to 99]
  • 'weekday' – Type: int, Range: See constants

Returns the current date (including weekday) and the current time of the real-time clock.

The following constants are available for this function:

For $weekday:

  • BrickletRealTimeClock::WEEKDAY_MONDAY = 1
  • BrickletRealTimeClock::WEEKDAY_TUESDAY = 2
  • BrickletRealTimeClock::WEEKDAY_WEDNESDAY = 3
  • BrickletRealTimeClock::WEEKDAY_THURSDAY = 4
  • BrickletRealTimeClock::WEEKDAY_FRIDAY = 5
  • BrickletRealTimeClock::WEEKDAY_SATURDAY = 6
  • BrickletRealTimeClock::WEEKDAY_SUNDAY = 7
int BrickletRealTimeClock::getTimestamp()
Returns:
  • $timestamp – Type: int, Unit: 1 ms, Range: [-263 to 263 - 1]

Returns the current date and the time of the real-time clock. The timestamp has an effective resolution of hundredths of a second and is an offset to 2000-01-01 00:00:00.000.

Advanced Functions

void BrickletRealTimeClock::setOffset(int $offset)
Parameters:
  • $offset – Type: int, Unit: 217/100 ppm, Range: [-128 to 127]

Sets the offset the real-time clock should compensate for in 2.17 ppm steps between -277.76 ppm (-128) and +275.59 ppm (127).

The real-time clock time can deviate from the actual time due to the frequency deviation of its 32.768 kHz crystal. Even without compensation (factory default) the resulting time deviation should be at most ±20 ppm (±52.6 seconds per month).

This deviation can be calculated by comparing the same duration measured by the real-time clock (rtc_duration) an accurate reference clock (ref_duration).

For best results the configured offset should be set to 0 ppm first and then a duration of at least 6 hours should be measured.

The new offset (new_offset) can be calculated from the currently configured offset (current_offset) and the measured durations as follow:

new_offset = current_offset - round(1000000 * (rtc_duration - ref_duration) / rtc_duration / 2.17)

If you want to calculate the offset, then we recommend using the calibration dialog in Brick Viewer, instead of doing it manually.

The offset is saved in the EEPROM of the Bricklet and only needs to be configured once.

int BrickletRealTimeClock::getOffset()
Returns:
  • $offset – Type: int, Unit: 217/100 ppm, Range: [-128 to 127]

Returns the offset as set by setOffset().

array BrickletRealTimeClock::getIdentity()
Return Array:
  • 'uid' – Type: string, Length: up to 8
  • 'connected_uid' – Type: string, Length: up to 8
  • 'position' – Type: string, Range: ['a' to 'h', 'i', '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). The Raspberry Pi HAT (Zero) Brick is always at position 'i' and the Bricklet connected to an Isolator Bricklet is always as 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 BrickletRealTimeClock::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 BrickletRealTimeClock::setDateTimeCallbackPeriod(int $period)
Parameters:
  • $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

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

The CALLBACK_DATE_TIME Callback is only triggered if the date or time changed since the last triggering.

New in version 2.0.1 (Plugin).

int BrickletRealTimeClock::getDateTimeCallbackPeriod()
Returns:
  • $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by setDateTimeCallbackPeriod().

New in version 2.0.1 (Plugin).

void BrickletRealTimeClock::setAlarm(int $month, int $day, int $hour, int $minute, int $second, int $weekday, int $interval)
Parameters:
  • $month – Type: int, Range: [-1, 2000 to 2099] with constants
  • $day – Type: int, Range: [-1, 1 to 12] with constants
  • $hour – Type: int, Range: [-1, 1 to 31] with constants
  • $minute – Type: int, Range: [-1 to 23] with constants
  • $second – Type: int, Range: [-1 to 59] with constants
  • $weekday – Type: int, Range: [-1 to 59] with constants
  • $interval – Type: int, Unit: 1 s, Range: See constants

Configures a repeatable alarm. The CALLBACK_ALARM callback is triggered if the current date and time matches the configured alarm.

Setting a parameter to -1 means that it should be disabled and doesn't take part in the match. Setting all parameters to -1 disables the alarm completely.

For example, to make the alarm trigger every day at 7:30 AM it can be configured as (-1, -1, 7, 30, -1, -1, -1). The hour is set to match 7 and the minute is set to match 30. The alarm is triggered if all enabled parameters match.

The interval has a special role. It allows to make the alarm reconfigure itself. This is useful if you need a repeated alarm that cannot be expressed by matching the current date and time. For example, to make the alarm trigger every 23 seconds it can be configured as (-1, -1, -1, -1, -1, -1, 23). Internally the Bricklet will take the current date and time, add 23 seconds to it and set the result as its alarm. The first alarm will be triggered 23 seconds after the call. Because the interval is not -1, the Bricklet will do the same again internally, take the current date and time, add 23 seconds to it and set that as its alarm. This results in a repeated alarm that triggers every 23 seconds.

The interval can also be used in combination with the other parameters. For example, configuring the alarm as (-1, -1, 7, 30, -1, -1, 300) results in an alarm that triggers every day at 7:30 AM and is then repeated every 5 minutes.

The following constants are available for this function:

For $month:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1

For $day:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1

For $hour:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1

For $minute:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1

For $second:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1

For $weekday:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1

For $interval:

  • BrickletRealTimeClock::ALARM_INTERVAL_DISABLED = -1

New in version 2.0.1 (Plugin).

array BrickletRealTimeClock::getAlarm()
Return Array:
  • 'month' – Type: int, Range: [-1, 2000 to 2099] with constants
  • 'day' – Type: int, Range: [-1, 1 to 12] with constants
  • 'hour' – Type: int, Range: [-1, 1 to 31] with constants
  • 'minute' – Type: int, Range: [-1 to 23] with constants
  • 'second' – Type: int, Range: [-1 to 59] with constants
  • 'weekday' – Type: int, Range: [-1 to 59] with constants
  • 'interval' – Type: int, Unit: 1 s, Range: See constants

Returns the alarm configuration as set by setAlarm().

The following constants are available for this function:

For $month:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1

For $day:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1

For $hour:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1

For $minute:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1

For $second:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1

For $weekday:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1

For $interval:

  • BrickletRealTimeClock::ALARM_INTERVAL_DISABLED = -1

New in version 2.0.1 (Plugin).

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";
}

$real_time_clock->registerCallback(BrickletRealTimeClock::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 BrickletRealTimeClock::CALLBACK_DATE_TIME
<?php   void callback(int $year, int $month, int $day, int $hour, int $minute, int $second, int $centisecond, int $weekday, int $timestamp [, mixed $user_data])   ?>
Callback Parameters:
  • $year – Type: int, Range: [2000 to 2099]
  • $month – Type: int, Range: [1 to 12]
  • $day – Type: int, Range: [1 to 31]
  • $hour – Type: int, Range: [0 to 23]
  • $minute – Type: int, Range: [0 to 59]
  • $second – Type: int, Range: [0 to 59]
  • $centisecond – Type: int, Range: [0 to 99]
  • $weekday – Type: int, Range: See constants
  • $timestamp – Type: int, Unit: 1 ms, Range: [-263 to 263 - 1]
  • $user_data – Type: mixed

This callback is triggered periodically with the period that is set by setDateTimeCallbackPeriod(). The parameters are the same as for getDateTime() and getTimestamp() combined.

The CALLBACK_DATE_TIME callback is only triggered if the date or time changed since the last triggering.

The following constants are available for this function:

For $weekday:

  • BrickletRealTimeClock::WEEKDAY_MONDAY = 1
  • BrickletRealTimeClock::WEEKDAY_TUESDAY = 2
  • BrickletRealTimeClock::WEEKDAY_WEDNESDAY = 3
  • BrickletRealTimeClock::WEEKDAY_THURSDAY = 4
  • BrickletRealTimeClock::WEEKDAY_FRIDAY = 5
  • BrickletRealTimeClock::WEEKDAY_SATURDAY = 6
  • BrickletRealTimeClock::WEEKDAY_SUNDAY = 7

New in version 2.0.1 (Plugin).

int BrickletRealTimeClock::CALLBACK_ALARM
<?php   void callback(int $year, int $month, int $day, int $hour, int $minute, int $second, int $centisecond, int $weekday, int $timestamp [, mixed $user_data])   ?>
Callback Parameters:
  • $year – Type: int, Range: [2000 to 2099]
  • $month – Type: int, Range: [1 to 12]
  • $day – Type: int, Range: [1 to 31]
  • $hour – Type: int, Range: [0 to 23]
  • $minute – Type: int, Range: [0 to 59]
  • $second – Type: int, Range: [0 to 59]
  • $centisecond – Type: int, Range: [0 to 99]
  • $weekday – Type: int, Range: See constants
  • $timestamp – Type: int, Unit: 1 ms, Range: [-263 to 263 - 1]
  • $user_data – Type: mixed

This callback is triggered every time the current date and time matches the configured alarm (see setAlarm()). The parameters are the same as for getDateTime() and getTimestamp() combined.

The following constants are available for this function:

For $weekday:

  • BrickletRealTimeClock::WEEKDAY_MONDAY = 1
  • BrickletRealTimeClock::WEEKDAY_TUESDAY = 2
  • BrickletRealTimeClock::WEEKDAY_WEDNESDAY = 3
  • BrickletRealTimeClock::WEEKDAY_THURSDAY = 4
  • BrickletRealTimeClock::WEEKDAY_FRIDAY = 5
  • BrickletRealTimeClock::WEEKDAY_SATURDAY = 6
  • BrickletRealTimeClock::WEEKDAY_SUNDAY = 7

New in version 2.0.1 (Plugin).

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

The following constants are available for this function:

For $function_id:

  • BrickletRealTimeClock::FUNCTION_SET_DATE_TIME = 1
  • BrickletRealTimeClock::FUNCTION_SET_OFFSET = 4
  • BrickletRealTimeClock::FUNCTION_SET_DATE_TIME_CALLBACK_PERIOD = 6
  • BrickletRealTimeClock::FUNCTION_SET_ALARM = 8
void BrickletRealTimeClock::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.

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 constants are available for this function:

For $function_id:

  • BrickletRealTimeClock::FUNCTION_SET_DATE_TIME = 1
  • BrickletRealTimeClock::FUNCTION_SET_OFFSET = 4
  • BrickletRealTimeClock::FUNCTION_SET_DATE_TIME_CALLBACK_PERIOD = 6
  • BrickletRealTimeClock::FUNCTION_SET_ALARM = 8
void BrickletRealTimeClock::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 BrickletRealTimeClock::DEVICE_IDENTIFIER

This constant is used to identify a Real-Time Clock 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 BrickletRealTimeClock::DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Real-Time Clock Bricklet.