PHP - Real-Time Clock Bricklet 2.0

This is the description of the PHP API bindings for the Real-Time Clock Bricklet 2.0. General information and technical specifications for the Real-Time Clock Bricklet 2.0 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/BrickletRealTimeClockV2.php');

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletRealTimeClockV2;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change XYZ to the UID of your Real-Time Clock Bricklet 2.0

$ipcon = new IPConnection(); // Create IP connection
$rtc = new BrickletRealTimeClockV2(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";
echo "Weekday: " . $date_time['weekday'] . "\n";
echo "Timestamp: " . $date_time['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/BrickletRealTimeClockV2.php');

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletRealTimeClockV2;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change XYZ to the UID of your Real-Time Clock Bricklet 2.0

// 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";
    echo "Weekday: $weekday\n";
    echo "Timestamp: $timestamp\n";
    echo "\n";
}

$ipcon = new IPConnection(); // Create IP connection
$rtc = new BrickletRealTimeClockV2(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(BrickletRealTimeClockV2::CALLBACK_DATE_TIME, 'cb_dateTime');

// Set period for date and time callback to 5s (5000ms)
$rtc->setDateTimeCallbackConfiguration(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 BrickletRealTimeClockV2(string $uid, IPConnection $ipcon)

Creates an object with the unique device ID $uid:

<?php   $real_time_clock_v2 = new BrickletRealTimeClockV2('YOUR_DEVICE_UID', $ipcon);   ?>

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

void BrickletRealTimeClockV2::setDateTime(int $year, int $month, int $day, int $hour, int $minute, int $second, int $centisecond, int $weekday)

Sets the current date (including weekday) and the current time with hundredths of a second resolution.

Possible value ranges:

  • Year: 2000 to 2099
  • Month: 1 to 12 (January to December)
  • Day: 1 to 31
  • Hour: 0 to 23
  • Minute: 0 to 59
  • Second: 0 to 59
  • Centisecond: 0 to 99
  • Weekday: 1 to 7 (Monday to Sunday)

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:

  • BrickletRealTimeClockV2::WEEKDAY_MONDAY = 1
  • BrickletRealTimeClockV2::WEEKDAY_TUESDAY = 2
  • BrickletRealTimeClockV2::WEEKDAY_WEDNESDAY = 3
  • BrickletRealTimeClockV2::WEEKDAY_THURSDAY = 4
  • BrickletRealTimeClockV2::WEEKDAY_FRIDAY = 5
  • BrickletRealTimeClockV2::WEEKDAY_SATURDAY = 6
  • BrickletRealTimeClockV2::WEEKDAY_SUNDAY = 7
array BrickletRealTimeClockV2::getDateTime()

Returns the current date (including weekday) and the current time of the real-time clock with hundredths of a second resolution.

The timestamp represents the current date and the the current time of the real-time clock converted to milliseconds.

The following constants are available for this function:

  • BrickletRealTimeClockV2::WEEKDAY_MONDAY = 1
  • BrickletRealTimeClockV2::WEEKDAY_TUESDAY = 2
  • BrickletRealTimeClockV2::WEEKDAY_WEDNESDAY = 3
  • BrickletRealTimeClockV2::WEEKDAY_THURSDAY = 4
  • BrickletRealTimeClockV2::WEEKDAY_FRIDAY = 5
  • BrickletRealTimeClockV2::WEEKDAY_SATURDAY = 6
  • BrickletRealTimeClockV2::WEEKDAY_SUNDAY = 7

The returned array has the keys year, month, day, hour, minute, second, centisecond, weekday and timestamp.

int BrickletRealTimeClockV2::getTimestamp()

Returns the current date and the time of the real-time clock converted to milliseconds. The timestamp has an effective resolution of hundredths of a second.

Advanced Functions

void BrickletRealTimeClockV2::setOffset(int $offset)

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 BrickletRealTimeClockV2::getOffset()

Returns the offset as set by setOffset().

array BrickletRealTimeClockV2::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 BrickletRealTimeClockV2::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 BrickletRealTimeClockV2::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.

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:

  • BrickletRealTimeClockV2::FUNCTION_SET_DATE_TIME = 1
  • BrickletRealTimeClockV2::FUNCTION_SET_OFFSET = 4
  • BrickletRealTimeClockV2::FUNCTION_SET_DATE_TIME_CALLBACK_CONFIGURATION = 6
  • BrickletRealTimeClockV2::FUNCTION_SET_ALARM = 8
  • BrickletRealTimeClockV2::FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletRealTimeClockV2::FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletRealTimeClockV2::FUNCTION_RESET = 243
  • BrickletRealTimeClockV2::FUNCTION_WRITE_UID = 248
void BrickletRealTimeClockV2::setResponseExpectedAll(bool $response_expected)

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

array BrickletRealTimeClockV2::getSPITFPErrorCount()

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

The returned array has the keys error_count_ack_checksum, error_count_message_checksum, error_count_frame and error_count_overflow.

int BrickletRealTimeClockV2::setBootloaderMode(int $mode)

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following constants are available for this function:

  • BrickletRealTimeClockV2::BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletRealTimeClockV2::BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletRealTimeClockV2::BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletRealTimeClockV2::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletRealTimeClockV2::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BrickletRealTimeClockV2::BOOTLOADER_STATUS_OK = 0
  • BrickletRealTimeClockV2::BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickletRealTimeClockV2::BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickletRealTimeClockV2::BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickletRealTimeClockV2::BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickletRealTimeClockV2::BOOTLOADER_STATUS_CRC_MISMATCH = 5
int BrickletRealTimeClockV2::getBootloaderMode()

Returns the current bootloader mode, see setBootloaderMode().

The following constants are available for this function:

  • BrickletRealTimeClockV2::BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletRealTimeClockV2::BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletRealTimeClockV2::BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletRealTimeClockV2::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletRealTimeClockV2::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
void BrickletRealTimeClockV2::setWriteFirmwarePointer(int $pointer)

Sets the firmware pointer for writeFirmware(). The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

int BrickletRealTimeClockV2::writeFirmware(array $data)

Writes 64 Bytes of firmware at the position as written by setWriteFirmwarePointer() before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

void BrickletRealTimeClockV2::setStatusLEDConfig(int $config)

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following constants are available for this function:

  • BrickletRealTimeClockV2::STATUS_LED_CONFIG_OFF = 0
  • BrickletRealTimeClockV2::STATUS_LED_CONFIG_ON = 1
  • BrickletRealTimeClockV2::STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletRealTimeClockV2::STATUS_LED_CONFIG_SHOW_STATUS = 3
int BrickletRealTimeClockV2::getStatusLEDConfig()

Returns the configuration as set by setStatusLEDConfig()

The following constants are available for this function:

  • BrickletRealTimeClockV2::STATUS_LED_CONFIG_OFF = 0
  • BrickletRealTimeClockV2::STATUS_LED_CONFIG_ON = 1
  • BrickletRealTimeClockV2::STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletRealTimeClockV2::STATUS_LED_CONFIG_SHOW_STATUS = 3
int BrickletRealTimeClockV2::getChipTemperature()

Returns the temperature in °C as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

void BrickletRealTimeClockV2::reset()

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

void BrickletRealTimeClockV2::writeUID(int $uid)

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

int BrickletRealTimeClockV2::readUID()

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

array BrickletRealTimeClockV2::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 BrickletRealTimeClockV2::registerCallback(int $callback_id, callable $callback, mixed $user_data=NULL)

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 BrickletRealTimeClockV2::setDateTimeCallbackConfiguration(int $period)

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

The default value is 0.

int BrickletRealTimeClockV2::getDateTimeCallbackConfiguration()

Returns the period as set by setDateTimeCallbackConfiguration().

void BrickletRealTimeClockV2::setAlarm(int $month, int $day, int $hour, int $minute, int $second, int $weekday, int $interval)

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:

  • BrickletRealTimeClockV2::ALARM_MATCH_DISABLED = -1
  • BrickletRealTimeClockV2::ALARM_INTERVAL_DISABLED = -1
array BrickletRealTimeClockV2::getAlarm()

Returns the alarm configuration as set by setAlarm().

The following constants are available for this function:

  • BrickletRealTimeClockV2::ALARM_MATCH_DISABLED = -1
  • BrickletRealTimeClockV2::ALARM_INTERVAL_DISABLED = -1

The returned array has the keys month, day, hour, minute, second, weekday and interval.

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_v2->registerCallback(BrickletRealTimeClockV2::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 BrickletRealTimeClockV2::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])   ?>

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

The following constants are available for this function:

  • BrickletRealTimeClockV2::WEEKDAY_MONDAY = 1
  • BrickletRealTimeClockV2::WEEKDAY_TUESDAY = 2
  • BrickletRealTimeClockV2::WEEKDAY_WEDNESDAY = 3
  • BrickletRealTimeClockV2::WEEKDAY_THURSDAY = 4
  • BrickletRealTimeClockV2::WEEKDAY_FRIDAY = 5
  • BrickletRealTimeClockV2::WEEKDAY_SATURDAY = 6
  • BrickletRealTimeClockV2::WEEKDAY_SUNDAY = 7
int BrickletRealTimeClockV2::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])   ?>

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().

The following constants are available for this function:

  • BrickletRealTimeClockV2::WEEKDAY_MONDAY = 1
  • BrickletRealTimeClockV2::WEEKDAY_TUESDAY = 2
  • BrickletRealTimeClockV2::WEEKDAY_WEDNESDAY = 3
  • BrickletRealTimeClockV2::WEEKDAY_THURSDAY = 4
  • BrickletRealTimeClockV2::WEEKDAY_FRIDAY = 5
  • BrickletRealTimeClockV2::WEEKDAY_SATURDAY = 6
  • BrickletRealTimeClockV2::WEEKDAY_SUNDAY = 7

Constants

int BrickletRealTimeClockV2::DEVICE_IDENTIFIER

This constant is used to identify a Real-Time Clock Bricklet 2.0.

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.

string BrickletRealTimeClockV2::DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Real-Time Clock Bricklet 2.0.