Ruby - Voltage/Current Bricklet

This is the description of the Ruby API bindings for the Voltage/Current Bricklet. General information and technical specifications for the Voltage/Current 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)

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#!/usr/bin/env ruby
# -*- ruby encoding: utf-8 -*-

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_voltage_current'

include Tinkerforge

HOST = 'localhost'
PORT = 4223
UID = 'XYZ' # Change XYZ to the UID of your Voltage/Current Bricklet

ipcon = IPConnection.new # Create IP connection
vc = BrickletVoltageCurrent.new UID, ipcon # Create device object

ipcon.connect HOST, PORT # Connect to brickd
# Don't use device before ipcon is connected

# Get current voltage
voltage = vc.get_voltage
puts "Voltage: #{voltage/1000.0} V"

# Get current current
current = vc.get_current
puts "Current: #{current/1000.0} A"

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

Callback

Download (example_callback.rb)

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#!/usr/bin/env ruby
# -*- ruby encoding: utf-8 -*-

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_voltage_current'

include Tinkerforge

HOST = 'localhost'
PORT = 4223
UID = 'XYZ' # Change XYZ to the UID of your Voltage/Current Bricklet

ipcon = IPConnection.new # Create IP connection
vc = BrickletVoltageCurrent.new UID, ipcon # Create device object

ipcon.connect HOST, PORT # Connect to brickd
# Don't use device before ipcon is connected

# Register current callback
vc.register_callback(BrickletVoltageCurrent::CALLBACK_CURRENT) do |current|
  puts "Current: #{current/1000.0} A"
end

# Set period for current callback to 1s (1000ms)
# Note: The current callback is only called every second
#       if the current has changed since the last call!
vc.set_current_callback_period 1000

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

Threshold

Download (example_threshold.rb)

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#!/usr/bin/env ruby
# -*- ruby encoding: utf-8 -*-

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_voltage_current'

include Tinkerforge

HOST = 'localhost'
PORT = 4223
UID = 'XYZ' # Change XYZ to the UID of your Voltage/Current Bricklet

ipcon = IPConnection.new # Create IP connection
vc = BrickletVoltageCurrent.new 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)
vc.set_debounce_period 10000

# Register power reached callback
vc.register_callback(BrickletVoltageCurrent::CALLBACK_POWER_REACHED) do |power|
  puts "Power: #{power/1000.0} W"
end

# Configure threshold for power "greater than 10 W"
vc.set_power_callback_threshold '>', 10*1000, 0

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

API

All methods listed below are thread-safe.

Basic Functions

BrickletVoltageCurrent::new(uid, ipcon) → voltage_current
Parameters:
  • uid – Type: str
  • ipcon – Type: IPConnection
Returns:
  • voltage_current – Type: BrickletVoltageCurrent

Creates an object with the unique device ID uid:

voltage_current = BrickletVoltageCurrent.new 'YOUR_DEVICE_UID', ipcon

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

BrickletVoltageCurrent#get_current → int
Returns:
  • current – Type: int, Range: [-231 to 231 - 1]

Returns the current. The value is in mA and between -20000mA and 20000mA.

If you want to get the current periodically, it is recommended to use the ::CALLBACK_CURRENT callback and set the period with #set_current_callback_period.

BrickletVoltageCurrent#get_voltage → int
Returns:
  • voltage – Type: int, Range: [-231 to 231 - 1]

Returns the voltage. The value is in mV and between 0mV and 36000mV.

If you want to get the voltage periodically, it is recommended to use the ::CALLBACK_VOLTAGE callback and set the period with #set_voltage_callback_period.

BrickletVoltageCurrent#get_power → int
Returns:
  • power – Type: int, Range: [-231 to 231 - 1]

Returns the power. The value is in mW and between 0mV and 720000mW.

If you want to get the power periodically, it is recommended to use the ::CALLBACK_POWER callback and set the period with #set_power_callback_period.

BrickletVoltageCurrent#set_configuration(averaging, voltage_conversion_time, current_conversion_time) → nil
Parameters:
  • averaging – Type: int, Range: See constants
  • voltage_conversion_time – Type: int, Range: [0 to 255]
  • current_conversion_time – Type: int, Range: [0 to 255]

Sets the configuration of the Voltage/Current Bricklet. It is possible to configure number of averages as well as voltage and current conversion time.

Averaging:

Value Number of Averages
0 1
1 4
2 16
3 64
4 128
5 256
6 512
>=7 1024

Voltage/Current conversion:

Value Conversion time
0 140µs
1 204µs
2 332µs
3 588µs
4 1.1ms
5 2.116ms
6 4.156ms
>=7 8.244ms

The default values are 3, 4 and 4 (64, 1.1ms, 1.1ms) for averaging, voltage conversion and current conversion.

The following constants are available for this function:

For averaging:

  • BrickletVoltageCurrent::AVERAGING_1 = 0
  • BrickletVoltageCurrent::AVERAGING_4 = 1
  • BrickletVoltageCurrent::AVERAGING_16 = 2
  • BrickletVoltageCurrent::AVERAGING_64 = 3
  • BrickletVoltageCurrent::AVERAGING_128 = 4
  • BrickletVoltageCurrent::AVERAGING_256 = 5
  • BrickletVoltageCurrent::AVERAGING_512 = 6
  • BrickletVoltageCurrent::AVERAGING_1024 = 7
BrickletVoltageCurrent#get_configuration → [int, int, int]
Return Array:
  • 0: averaging – Type: int, Range: See constants
  • 1: voltage_conversion_time – Type: int, Range: [0 to 255]
  • 2: current_conversion_time – Type: int, Range: [0 to 255]

Returns the configuration as set by #set_configuration.

The following constants are available for this function:

For averaging:

  • BrickletVoltageCurrent::AVERAGING_1 = 0
  • BrickletVoltageCurrent::AVERAGING_4 = 1
  • BrickletVoltageCurrent::AVERAGING_16 = 2
  • BrickletVoltageCurrent::AVERAGING_64 = 3
  • BrickletVoltageCurrent::AVERAGING_128 = 4
  • BrickletVoltageCurrent::AVERAGING_256 = 5
  • BrickletVoltageCurrent::AVERAGING_512 = 6
  • BrickletVoltageCurrent::AVERAGING_1024 = 7

Advanced Functions

BrickletVoltageCurrent#set_calibration(gain_multiplier, gain_divisor) → nil
Parameters:
  • gain_multiplier – Type: int, Range: [0 to 216 - 1]
  • gain_divisor – Type: int, Range: [0 to 216 - 1]

Since the shunt resistor that is used to measure the current is not perfectly precise, it needs to be calibrated by a multiplier and divisor if a very precise reading is needed.

For example, if you are expecting a measurement of 1000mA and you are measuring 1023mA, you can calibrate the Voltage/Current Bricklet by setting the multiplier to 1000 and the divisor to 1023.

BrickletVoltageCurrent#get_calibration → [int, int]
Return Array:
  • 0: gain_multiplier – Type: int, Range: [0 to 216 - 1]
  • 1: gain_divisor – Type: int, Range: [0 to 216 - 1]

Returns the calibration as set by #set_calibration.

BrickletVoltageCurrent#get_api_version → [int, ...]
Returns:
  • api_version – Type: [int, ...], Length: 3, Range: [0 to 255]

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.

BrickletVoltageCurrent#get_response_expected(function_id) → bool
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 #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.

The following constants are available for this function:

For function_id:

  • BrickletVoltageCurrent::FUNCTION_SET_CONFIGURATION = 4
  • BrickletVoltageCurrent::FUNCTION_SET_CALIBRATION = 6
  • BrickletVoltageCurrent::FUNCTION_SET_CURRENT_CALLBACK_PERIOD = 8
  • BrickletVoltageCurrent::FUNCTION_SET_VOLTAGE_CALLBACK_PERIOD = 10
  • BrickletVoltageCurrent::FUNCTION_SET_POWER_CALLBACK_PERIOD = 12
  • BrickletVoltageCurrent::FUNCTION_SET_CURRENT_CALLBACK_THRESHOLD = 14
  • BrickletVoltageCurrent::FUNCTION_SET_VOLTAGE_CALLBACK_THRESHOLD = 16
  • BrickletVoltageCurrent::FUNCTION_SET_POWER_CALLBACK_THRESHOLD = 18
  • BrickletVoltageCurrent::FUNCTION_SET_DEBOUNCE_PERIOD = 20
BrickletVoltageCurrent#set_response_expected(function_id, response_expected) → nil
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:

  • BrickletVoltageCurrent::FUNCTION_SET_CONFIGURATION = 4
  • BrickletVoltageCurrent::FUNCTION_SET_CALIBRATION = 6
  • BrickletVoltageCurrent::FUNCTION_SET_CURRENT_CALLBACK_PERIOD = 8
  • BrickletVoltageCurrent::FUNCTION_SET_VOLTAGE_CALLBACK_PERIOD = 10
  • BrickletVoltageCurrent::FUNCTION_SET_POWER_CALLBACK_PERIOD = 12
  • BrickletVoltageCurrent::FUNCTION_SET_CURRENT_CALLBACK_THRESHOLD = 14
  • BrickletVoltageCurrent::FUNCTION_SET_VOLTAGE_CALLBACK_THRESHOLD = 16
  • BrickletVoltageCurrent::FUNCTION_SET_POWER_CALLBACK_THRESHOLD = 18
  • BrickletVoltageCurrent::FUNCTION_SET_DEBOUNCE_PERIOD = 20
BrickletVoltageCurrent#set_response_expected_all(response_expected) → nil
Parameters:
  • response_expected – Type: bool

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

BrickletVoltageCurrent#get_identity → [str, str, chr, [int, ...], [int, ...], int]
Return Array:
  • 0: uid – Type: str, Length: up to 8
  • 1: connected_uid – Type: str, Length: up to 8
  • 2: position – Type: chr
  • 3: hardware_version – Type: [int, ...], Length: 3, Range: [0 to 255]
  • 4: firmware_version – Type: [int, ...], Length: 3, Range: [0 to 255]
  • 5: 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' or 'd'.

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

Callback Configuration Functions

BrickletVoltageCurrent#register_callback(callback_id) { |param [, ...]| block } → nil
Parameters:
  • callback_id – Type: int

Registers the given block with the given callback_id.

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

BrickletVoltageCurrent#set_current_callback_period(period) → nil
Parameters:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

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

The ::CALLBACK_CURRENT callback is only triggered if the current has changed since the last triggering.

BrickletVoltageCurrent#get_current_callback_period → int
Returns:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by #set_current_callback_period.

BrickletVoltageCurrent#set_voltage_callback_period(period) → nil
Parameters:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

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

The ::CALLBACK_VOLTAGE callback is only triggered if the voltage has changed since the last triggering.

BrickletVoltageCurrent#get_voltage_callback_period → int
Returns:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by #set_voltage_callback_period.

BrickletVoltageCurrent#set_power_callback_period(period) → nil
Parameters:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

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

The ::CALLBACK_POWER callback is only triggered if the power has changed since the last triggering.

BrickletVoltageCurrent#get_power_callback_period → int
Returns:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by #get_power_callback_period.

BrickletVoltageCurrent#set_current_callback_threshold(option, min, max) → nil
Parameters:
  • option – Type: chr, Range: See constants, Default: 'x'
  • min – Type: int, Range: [-231 to 231 - 1]
  • max – Type: int, Range: [-231 to 231 - 1]

Sets the thresholds for the ::CALLBACK_CURRENT_REACHED callback.

The following options are possible:

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

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

The following constants are available for this function:

For option:

  • BrickletVoltageCurrent::THRESHOLD_OPTION_OFF = 'x'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_SMALLER = '<'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_GREATER = '>'
BrickletVoltageCurrent#get_current_callback_threshold → [chr, int, int]
Return Array:
  • 0: option – Type: chr, Range: See constants, Default: 'x'
  • 1: min – Type: int, Range: [-231 to 231 - 1]
  • 2: max – Type: int, Range: [-231 to 231 - 1]

Returns the threshold as set by #set_current_callback_threshold.

The following constants are available for this function:

For option:

  • BrickletVoltageCurrent::THRESHOLD_OPTION_OFF = 'x'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_SMALLER = '<'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_GREATER = '>'
BrickletVoltageCurrent#set_voltage_callback_threshold(option, min, max) → nil
Parameters:
  • option – Type: chr, Range: See constants, Default: 'x'
  • min – Type: int, Range: [-231 to 231 - 1]
  • max – Type: int, Range: [-231 to 231 - 1]

Sets the thresholds for the ::CALLBACK_VOLTAGE_REACHED callback.

The following options are possible:

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

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

The following constants are available for this function:

For option:

  • BrickletVoltageCurrent::THRESHOLD_OPTION_OFF = 'x'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_SMALLER = '<'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_GREATER = '>'
BrickletVoltageCurrent#get_voltage_callback_threshold → [chr, int, int]
Return Array:
  • 0: option – Type: chr, Range: See constants, Default: 'x'
  • 1: min – Type: int, Range: [-231 to 231 - 1]
  • 2: max – Type: int, Range: [-231 to 231 - 1]

Returns the threshold as set by #set_voltage_callback_threshold.

The following constants are available for this function:

For option:

  • BrickletVoltageCurrent::THRESHOLD_OPTION_OFF = 'x'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_SMALLER = '<'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_GREATER = '>'
BrickletVoltageCurrent#set_power_callback_threshold(option, min, max) → nil
Parameters:
  • option – Type: chr, Range: See constants, Default: 'x'
  • min – Type: int, Range: [-231 to 231 - 1]
  • max – Type: int, Range: [-231 to 231 - 1]

Sets the thresholds for the ::CALLBACK_POWER_REACHED callback.

The following options are possible:

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

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

The following constants are available for this function:

For option:

  • BrickletVoltageCurrent::THRESHOLD_OPTION_OFF = 'x'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_SMALLER = '<'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_GREATER = '>'
BrickletVoltageCurrent#get_power_callback_threshold → [chr, int, int]
Return Array:
  • 0: option – Type: chr, Range: See constants, Default: 'x'
  • 1: min – Type: int, Range: [-231 to 231 - 1]
  • 2: max – Type: int, Range: [-231 to 231 - 1]

Returns the threshold as set by #set_power_callback_threshold.

The following constants are available for this function:

For option:

  • BrickletVoltageCurrent::THRESHOLD_OPTION_OFF = 'x'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_SMALLER = '<'
  • BrickletVoltageCurrent::THRESHOLD_OPTION_GREATER = '>'
BrickletVoltageCurrent#set_debounce_period(debounce) → nil
Parameters:
  • debounce – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Sets the period with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

BrickletVoltageCurrent#get_debounce_period → int
Returns:
  • debounce – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Returns the debounce period as set by #set_debounce_period.

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:

voltage_current.register_callback BrickletVoltageCurrent::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.

BrickletVoltageCurrent::CALLBACK_CURRENT
Callback Parameters:
  • current – Type: int, Range: [-231 to 231 - 1]

This callback is triggered periodically with the period that is set by #set_current_callback_period. The parameter is the current of the sensor.

The ::CALLBACK_CURRENT callback is only triggered if the current has changed since the last triggering.

BrickletVoltageCurrent::CALLBACK_VOLTAGE
Callback Parameters:
  • voltage – Type: int, Range: [-231 to 231 - 1]

This callback is triggered periodically with the period that is set by #set_voltage_callback_period. The parameter is the voltage of the sensor.

The ::CALLBACK_VOLTAGE callback is only triggered if the voltage has changed since the last triggering.

BrickletVoltageCurrent::CALLBACK_POWER
Callback Parameters:
  • power – Type: int, Range: [-231 to 231 - 1]

This callback is triggered periodically with the period that is set by #set_power_callback_period. The parameter is the power of the sensor.

The ::CALLBACK_POWER callback is only triggered if the power has changed since the last triggering.

BrickletVoltageCurrent::CALLBACK_CURRENT_REACHED
Callback Parameters:
  • current – Type: int, Range: [-231 to 231 - 1]

This callback is triggered when the threshold as set by #set_current_callback_threshold is reached. The parameter is the current of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by #set_debounce_period.

BrickletVoltageCurrent::CALLBACK_VOLTAGE_REACHED
Callback Parameters:
  • voltage – Type: int, Range: [-231 to 231 - 1]

This callback is triggered when the threshold as set by #set_voltage_callback_threshold is reached. The parameter is the voltage of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by #set_debounce_period.

BrickletVoltageCurrent::CALLBACK_POWER_REACHED
Callback Parameters:
  • power – Type: int, Range: [-231 to 231 - 1]

This callback is triggered when the threshold as set by #set_power_callback_threshold is reached. The parameter is the power of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by #set_debounce_period.

Constants

BrickletVoltageCurrent::DEVICE_IDENTIFIER

This constant is used to identify a Voltage/Current Bricklet.

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

BrickletVoltageCurrent::DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Voltage/Current Bricklet.