Ruby - Real-Time Clock Bricklet

This is the description of the Ruby 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 Ruby API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Simple

Download (example_simple.rb)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
#!/usr/bin/env ruby
# -*- ruby encoding: utf-8 -*-

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_real_time_clock'

include Tinkerforge

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

ipcon = IPConnection.new # Create IP connection
rtc = BrickletRealTimeClock.new 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 as [year, month, day, hour, minute, second, centisecond,
#                               weekday]
date_time = rtc.get_date_time

puts "Year: #{date_time[0]}"
puts "Month: #{date_time[1]}"
puts "Day: #{date_time[2]}"
puts "Hour: #{date_time[3]}"
puts "Minute: #{date_time[4]}"
puts "Second: #{date_time[5]}"
puts "Centisecond: #{date_time[6]}"
puts "Weekday: #{date_time[7]}"

# Get current timestamp
timestamp = rtc.get_timestamp
puts "Timestamp: #{timestamp} ms"

puts 'Press key to exit'
$stdin.gets
ipcon.disconnect

Callback

Download (example_callback.rb)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
#!/usr/bin/env ruby
# -*- ruby encoding: utf-8 -*-

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_real_time_clock'

include Tinkerforge

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

ipcon = IPConnection.new # Create IP connection
rtc = BrickletRealTimeClock.new 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
rtc.register_callback(BrickletRealTimeClock::CALLBACK_DATE_TIME) do |year, month, day,
                                                                     hour, minute, second,
                                                                     centisecond, weekday,
                                                                     timestamp|
  puts "Year: #{year}"
  puts "Month: #{month}"
  puts "Day: #{day}"
  puts "Hour: #{hour}"
  puts "Minute: #{minute}"
  puts "Second: #{second}"
  puts "Centisecond: #{centisecond}"
  puts "Weekday: #{weekday}"
  puts "Timestamp: #{timestamp}"
  puts ''
end

# 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.set_date_time_callback_period 5000

puts 'Press key to exit'
$stdin.gets
ipcon.disconnect

API

All methods listed below are thread-safe.

Basic Functions

BrickletRealTimeClock::new(uid, ipcon) → real_time_clock
Parameters:
  • uid -- str
  • ipcon -- IPConnection

Creates an object with the unique device ID uid:

real_time_clock = BrickletRealTimeClock.new 'YOUR_DEVICE_UID', ipcon

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

BrickletRealTimeClock#set_date_time(year, month, day, hour, minute, second, centisecond, weekday) → nil
Parameters:
  • year -- int
  • month -- int
  • day -- int
  • hour -- int
  • minute -- int
  • second -- int
  • centisecond -- int
  • weekday -- int

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:

  • 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
BrickletRealTimeClock#get_date_time → [int, int, int, int, int, int, int, int]

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

The following constants are available for this function:

  • 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

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

BrickletRealTimeClock#get_timestamp → int

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

BrickletRealTimeClock#set_offset(offset) → nil
Parameters:offset -- int

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.

BrickletRealTimeClock#get_offset → int

Returns the offset as set by #set_offset.

BrickletRealTimeClock#get_api_version → [int, int, int]

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.

BrickletRealTimeClock#get_response_expected(function_id) → bool
Parameters:function_id -- int

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 #set_response_expected. 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 #set_response_expected for the list of function ID constants available for this function.

BrickletRealTimeClock#set_response_expected(function_id, response_expected) → nil
Parameters:
  • function_id -- int
  • response_expected -- 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 function ID constants are available for this function:

  • BrickletRealTimeClock::FUNCTION_SET_DATE_TIME = 1
  • BrickletRealTimeClock::FUNCTION_SET_OFFSET = 4
  • BrickletRealTimeClock::FUNCTION_SET_DATE_TIME_CALLBACK_PERIOD = 6
  • BrickletRealTimeClock::FUNCTION_SET_ALARM = 8
BrickletRealTimeClock#set_response_expected_all(response_expected) → nil
Parameters:response_expected -- bool

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

BrickletRealTimeClock#get_identity → [str, str, str, [int, int, int], [int, int, int], int]

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 values uid, connected_uid, position, hardware_version, firmware_version and device_identifier.

Callback Configuration Functions

BrickletRealTimeClock#register_callback(callback_id) { |param [, ...]| block } → nil
Parameters:callback_id -- int

Registers the given block with the given callback_id.

The available callback IDs with corresponding function signatures are listed below.

BrickletRealTimeClock#set_date_time_callback_period(period) → nil
Parameters:period -- int

Sets the period in ms 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.

The default value is 0.

New in version 2.0.1 (Plugin).

BrickletRealTimeClock#get_date_time_callback_period → int

Returns the period as set by #set_date_time_callback_period.

New in version 2.0.1 (Plugin).

BrickletRealTimeClock#set_alarm(month, day, hour, minute, second, weekday, interval) → nil
Parameters:
  • month -- int
  • day -- int
  • hour -- int
  • minute -- int
  • second -- int
  • weekday -- int
  • interval -- int

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:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1
  • BrickletRealTimeClock::ALARM_INTERVAL_DISABLED = -1

New in version 2.0.1 (Plugin).

BrickletRealTimeClock#get_alarm → [int, int, int, int, int, int, int]

Returns the alarm configuration as set by #set_alarm.

The following constants are available for this function:

  • BrickletRealTimeClock::ALARM_MATCH_DISABLED = -1
  • BrickletRealTimeClock::ALARM_INTERVAL_DISABLED = -1

New in version 2.0.1 (Plugin).

The returned array has the values 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 #register_callback function of the device object. The first parameter is the callback ID and the second parameter is a block:

real_time_clock.register_callback BrickletRealTimeClock::CALLBACK_EXAMPLE, do |param|
  puts "#{param}"
end

The available constants with inherent number and type of parameters 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.

BrickletRealTimeClock::CALLBACK_DATE_TIME
Parameters:
  • year -- int
  • month -- int
  • day -- int
  • hour -- int
  • minute -- int
  • second -- int
  • centisecond -- int
  • weekday -- int
  • timestamp -- int

This callback is triggered periodically with the period that is set by #set_date_time_callback_period. The parameters are the same as for #get_date_time and #get_timestamp 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:

  • 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).

BrickletRealTimeClock::CALLBACK_ALARM
Parameters:
  • year -- int
  • month -- int
  • day -- int
  • hour -- int
  • minute -- int
  • second -- int
  • centisecond -- int
  • weekday -- int
  • timestamp -- int

This callback is triggered every time the current date and time matches the configured alarm (see #set_alarm). The parameters are the same as for #get_date_time and #get_timestamp combined.

The following constants are available for this function:

  • 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).

Constants

BrickletRealTimeClock::DEVICE_IDENTIFIER

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

The #get_identity() function and the ::CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

BrickletRealTimeClock::DEVICE_DISPLAY_NAME

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