MQTT - Real-Time Clock Bricklet 2.0¶

Simple¶

Download (example-simple.txt)

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# Change XYZ to the UID of your Real-Time Clock Bricklet 2.0

setup:
    # Get current date and time
    subscribe to tinkerforge/response/real_time_clock_v2_bricklet/XYZ/get_date_time
    publish '' to tinkerforge/request/real_time_clock_v2_bricklet/XYZ/get_date_time

Callback¶

Download (example-callback.txt)

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# Change XYZ to the UID of your Real-Time Clock Bricklet 2.0

setup:
    # Handle incoming date and time callbacks
    subscribe to tinkerforge/callback/real_time_clock_v2_bricklet/XYZ/date_time
    publish '{"register": true}' to tinkerforge/register/real_time_clock_v2_bricklet/XYZ/date_time # Register date_time callback

    # Set period for date and time callback to 5s (5000ms)
    publish '{"period": 5000, "value_has_to_change": }' to tinkerforge/request/real_time_clock_v2_bricklet/XYZ/set_date_time_callback_configuration

Basic Functions¶

request/real_time_clock_v2_bricklet/<UID>/set_date_time¶

Request:	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 symbols
Response:	no response

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 symbols are available for this function:

For weekday:

• "monday" = 1
• "tuesday" = 2
• "wednesday" = 3
• "thursday" = 4
• "friday" = 5
• "saturday" = 6
• "sunday" = 7

request/real_time_clock_v2_bricklet/<UID>/get_date_time¶

Request:	empty payload
Response:	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 symbols timestamp – Type: int, Unit: 1 ms, Range: [-263 to 263 - 1]

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

The timestamp represents the current date and the the current time of the real-time clock converted to milliseconds and is an offset to 2000-01-01 00:00:00.0000.

The following symbols are available for this function:

For weekday:

• "monday" = 1
• "tuesday" = 2
• "wednesday" = 3
• "thursday" = 4
• "friday" = 5
• "saturday" = 6
• "sunday" = 7

request/real_time_clock_v2_bricklet/<UID>/get_timestamp¶

Request:	empty payload
Response:	timestamp – Type: int, Unit: 1 ms, Range: [-263 to 263 - 1]

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 and is an offset to 2000-01-01 00:00:00.0000.

Advanced Functions¶

request/real_time_clock_v2_bricklet/<UID>/set_offset¶

Request:	offset – Type: int, Unit: 217/100 ppm, Range: [-128 to 127]
Response:	no response

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.

request/real_time_clock_v2_bricklet/<UID>/get_offset¶

Request:	empty payload
Response:	offset – Type: int, Unit: 217/100 ppm, Range: [-128 to 127]

Returns the offset as set by request/real_time_clock_v2_bricklet/<UID>/set_offset.

request/real_time_clock_v2_bricklet/<UID>/get_spitfp_error_count¶

Request:	empty payload
Response:	error_count_ack_checksum – Type: int, Range: [0 to 232 - 1] error_count_message_checksum – Type: int, Range: [0 to 232 - 1] error_count_frame – Type: int, Range: [0 to 232 - 1] error_count_overflow – Type: int, Range: [0 to 232 - 1]

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.

request/real_time_clock_v2_bricklet/<UID>/set_status_led_config¶

Request:	config – Type: int, Range: See symbols, Default: 3
Response:	no response

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 symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_status" = 3

request/real_time_clock_v2_bricklet/<UID>/get_status_led_config¶

Request:	empty payload
Response:	config – Type: int, Range: See symbols, Default: 3

Returns the configuration as set by request/real_time_clock_v2_bricklet/<UID>/set_status_led_config

The following symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_status" = 3

request/real_time_clock_v2_bricklet/<UID>/get_chip_temperature¶

Request:	empty payload
Response:	temperature – Type: int, Unit: 1 °C, Range: [-215 to 215 - 1]

Returns the temperature 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.

request/real_time_clock_v2_bricklet/<UID>/reset¶

Request:	empty payload
Response:	no response

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!

request/real_time_clock_v2_bricklet/<UID>/get_identity¶

Request:

empty payload

Response:

uid – Type: string, Length: up to 8 connected_uid – Type: string, Length: up to 8 position – Type: char, Range: ["a" to "h", "z"] hardware_version – Type: [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: [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] _display_name – Type: string

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. If symbolic output is not disabled, the device identifier is mapped to the corresponding name in the format used in topics.

The display name contains the Real-Time Clock 2.0's name in a human readable form.

Callback Configuration Functions¶

request/real_time_clock_v2_bricklet/<UID>/set_date_time_callback_configuration¶

Request:	period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Response:	no response

Sets the period with which the register/real_time_clock_v2_bricklet/<UID>/date_time callback is triggered periodically. A value of 0 turns the callback off.

request/real_time_clock_v2_bricklet/<UID>/get_date_time_callback_configuration¶

Request:	empty payload
Response:	period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by request/real_time_clock_v2_bricklet/<UID>/set_date_time_callback_configuration.

request/real_time_clock_v2_bricklet/<UID>/set_alarm¶

Request:	month – Type: int, Range: [-1, 1 to 12] with symbols day – Type: int, Range: [-1, 1 to 31] with symbols hour – Type: int, Range: [-1, 0 to 23] with symbols minute – Type: int, Range: [-1, 0 to 59] with symbols second – Type: int, Range: [-1, 0 to 59] with symbols weekday – Type: int, Range: [-1, 1 to 7] with symbols interval – Type: int, Unit: 1 s, Range: [-1, 1 to 231 - 1] with symbols
Response:	no response

Configures a repeatable alarm. The register/real_time_clock_v2_bricklet/<UID>/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 symbols are available for this function:

For month:

• "disabled" = -1

For day:

• "disabled" = -1

For hour:

• "disabled" = -1

For minute:

• "disabled" = -1

For second:

• "disabled" = -1

For weekday:

• "disabled" = -1

For interval:

• "disabled" = -1

request/real_time_clock_v2_bricklet/<UID>/get_alarm¶

Request:	empty payload
Response:	month – Type: int, Range: [-1, 1 to 12] with symbols day – Type: int, Range: [-1, 1 to 31] with symbols hour – Type: int, Range: [-1, 0 to 23] with symbols minute – Type: int, Range: [-1, 0 to 59] with symbols second – Type: int, Range: [-1, 0 to 59] with symbols weekday – Type: int, Range: [-1, 1 to 7] with symbols interval – Type: int, Unit: 1 s, Range: [-1, 1 to 231 - 1] with symbols

Returns the alarm configuration as set by request/real_time_clock_v2_bricklet/<UID>/set_alarm.

The following symbols are available for this function:

For month:

• "disabled" = -1

For day:

• "disabled" = -1

For hour:

• "disabled" = -1

For minute:

• "disabled" = -1

For second:

• "disabled" = -1

For weekday:

• "disabled" = -1

For interval:

• "disabled" = -1

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the corresponding .../register/... topic and an optional suffix. This suffix can be used to deregister the callback later.

register/real_time_clock_v2_bricklet/<UID>/date_time¶

Register Request:	register – Type: bool
Callback Response:	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 symbols timestamp – Type: int, Unit: 1 ms, Range: [-263 to 263 - 1]

A callback can be registered for this event by publishing to the .../register/real_time_clock_v2_bricklet/<UID>/date_time[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/real_time_clock_v2_bricklet/<UID>/date_time[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/real_time_clock_v2_bricklet/<UID>/set_date_time_callback_configuration. The callback payload members are the same as for request/real_time_clock_v2_bricklet/<UID>/get_date_time.

The following symbols are available for this function:

For weekday:

• "monday" = 1
• "tuesday" = 2
• "wednesday" = 3
• "thursday" = 4
• "friday" = 5
• "saturday" = 6
• "sunday" = 7

register/real_time_clock_v2_bricklet/<UID>/alarm¶

Register Request:	register – Type: bool
Callback Response:	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 symbols timestamp – Type: int, Unit: 1 ms, Range: [-263 to 263 - 1]

A callback can be registered for this event by publishing to the .../register/real_time_clock_v2_bricklet/<UID>/alarm[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/real_time_clock_v2_bricklet/<UID>/alarm[/<SUFFIX>] topic for each registered suffix.

This callback is triggered every time the current date and time matches the configured alarm (see request/real_time_clock_v2_bricklet/<UID>/set_alarm). The callback payload members are the same as for request/real_time_clock_v2_bricklet/<UID>/get_date_time.

The following symbols are available for this function:

For weekday:

• "monday" = 1
• "tuesday" = 2
• "wednesday" = 3
• "thursday" = 4
• "friday" = 5
• "saturday" = 6
• "sunday" = 7

Internal Functions¶

Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.

request/real_time_clock_v2_bricklet/<UID>/set_bootloader_mode¶

Request:	mode – Type: int, Range: See symbols
Response:	status – Type: int, Range: See symbols

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 symbols are available for this function:

For mode:

• "bootloader" = 0
• "firmware" = 1
• "bootloader_wait_for_reboot" = 2
• "firmware_wait_for_reboot" = 3
• "firmware_wait_for_erase_and_reboot" = 4

For status:

• "ok" = 0
• "invalid_mode" = 1
• "no_change" = 2
• "entry_function_not_present" = 3
• "device_identifier_incorrect" = 4
• "crc_mismatch" = 5

request/real_time_clock_v2_bricklet/<UID>/get_bootloader_mode¶

Request:	empty payload
Response:	mode – Type: int, Range: See symbols

Returns the current bootloader mode, see request/real_time_clock_v2_bricklet/<UID>/set_bootloader_mode.

The following symbols are available for this function:

For mode:

• "bootloader" = 0
• "firmware" = 1
• "bootloader_wait_for_reboot" = 2
• "firmware_wait_for_reboot" = 3
• "firmware_wait_for_erase_and_reboot" = 4

request/real_time_clock_v2_bricklet/<UID>/set_write_firmware_pointer¶

Request:	pointer – Type: int, Unit: 1 B, Range: [0 to 232 - 1]
Response:	no response

Sets the firmware pointer for request/real_time_clock_v2_bricklet/<UID>/write_firmware. 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.

request/real_time_clock_v2_bricklet/<UID>/write_firmware¶

Request:	data – Type: [int, ...], Length: 64, Range: [0 to 255]
Response:	status – Type: int, Range: [0 to 255]

Writes 64 Bytes of firmware at the position as written by request/real_time_clock_v2_bricklet/<UID>/set_write_firmware_pointer 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.

request/real_time_clock_v2_bricklet/<UID>/write_uid¶

Request:	uid – Type: int, Range: [0 to 232 - 1]
Response:	no response

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.

request/real_time_clock_v2_bricklet/<UID>/read_uid¶

Request:	empty payload
Response:	uid – Type: int, Range: [0 to 232 - 1]

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