Ruby - IO-4 Bricklet

This is the API description for the Ruby bindings of the IO-4 Bricklet. General information on what this device does and the technical specifications can be found here.

A tutorial on how to test the IO-4 Bricklet and get the first examples running can be found here.

Examples

The example code below is public domain.

Output

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

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_io4'

include Tinkerforge

HOST = 'localhost'
PORT = 4223
UID = '6hY' # Change to your UID

ipcon = IPConnection.new # Create IP connection
io4 = BrickletIO4.new UID, ipcon # Create device object

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


# Set pin 1 to output low
io4.set_configuration 1 << 1, 'o', false

# Set pin 2 and 3 to output high
io4.set_configuration((1 << 2) | (1 << 3), 'o', true)

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

Interrupt

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

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_io4'

include Tinkerforge

HOST = 'localhost'
PORT = 4223
UID = '6hY' # Change to your UID

ipcon = IPConnection.new # Create IP connection
io4 = BrickletIO4.new UID, ipcon # Create device object

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

# Register callback for interrupts
io4.register_callback(BrickletIO4::CALLBACK_INTERRUPT) do |interrupt_mask, value_mask|
  puts "Interrupt by: #{interrupt_mask.to_s 2}"
  puts "Value: #{value_mask.to_s 2}"
end

# Enable interrupt on pin 0
io4.set_interrupt 1 << 0

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

API

All methods listed below are thread-safe.

Basic Functions

BrickletIO4::new(uid, ipcon) → io4

Parameters:

• uid – str
• ipcon – IPConnection

Creates an object with the unique device ID uid:

io4 = BrickletIO4.new 'YOUR_DEVICE_UID', ipcon

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

BrickletIO4#set_value(value_mask) → nil

Parameters:value_mask – int

Sets the output value (high or low) with a bitmask. The bitmask is 4 bit long, true refers to high and false refers to low.

For example: The value 0b0011 will turn the pins 0-1 high and the pins 2-3 low.

Note

This function does nothing for pins that are configured as input. Pull-up resistors can be switched on with #set_configuration.

BrickletIO4#get_value → int

Returns a bitmask of the values that are currently measured. This function works if the pin is configured to input as well as if it is configured to output.

BrickletIO4#set_configuration(selection_mask, direction, value) → nil

Parameters:

• selection_mask – int
• direction – str
• value – bool

Configures the value and direction of the specified pins. Possible directions are “i” and “o” for input and output.

If the direction is configured as output, the value is either high or low (set as true or false).

If the direction is configured as input, the value is either pull-up or default (set as true or false).

For example:

• (15, ‘i’, true) will set all pins of as input pull-up.
• (8, ‘i’, false) will set pin 3 of as input default (floating if nothing is connected).
• (3, ‘o’, false) will set pins 0 and 1 as output low.
• (4, ‘o’, true) will set pin 2 of as output high.

The following constants are available for this function:

• BrickletIO4::DIRECTION_IN = ‘i’
• BrickletIO4::DIRECTION_OUT = ‘o’

BrickletIO4#get_configuration → [int, int]

Returns a value bitmask and a direction bitmask.

For example: A return value of 0b0011 and 0b0101 for direction and value means that:

• pin 0 is configured as input pull-up,
• pin 1 is configured as input default,
• pin 2 is configured as output high
• and pin 3 is are configured as output low.

The returned tuple has the values direction_mask and value_mask.

Advanced Functions

BrickletIO4#set_monoflop(selection_mask, value_mask, time) → nil

Parameters:

• selection_mask – int
• value_mask – int
• time – int

Configures a monoflop of the pins specified by the first parameter as 4 bit long bitmask. The specified pins must be configured for output. Non-output pins will be ignored.

The second parameter is a bitmask with the desired value of the specified output pins (true means high and false means low).

The third parameter indicates the time (in ms) that the pins should hold the value.

If this function is called with the parameters ((1 << 0) | (1 << 3), (1 << 0), 1500): Pin 0 will get high and pin 3 will get low. In 1.5s pin 0 will get low and pin 3 will get high again.

A monoflop can be used as a fail-safe mechanism. For example: Lets assume you have a RS485 bus and an IO-4 Bricklet connected to one of the slave stacks. You can now call this function every second, with a time parameter of two seconds and pin 0 set to high. Pin 0 will be high all the time. If now the RS485 connection is lost, then pin 0 will get low in at most two seconds.

New in version 1.1.1 (Plugin).

BrickletIO4#get_monoflop(pin) → [int, int, int]

Parameters:pin – int

Returns (for the given pin) the current value and the time as set by #set_monoflop as well as the remaining time until the value flips.

If the timer is not running currently, the remaining time will be returned as 0.

New in version 1.1.1 (Plugin).

The returned tuple has the values value, time and time_remaining.

BrickletIO4#set_selected_values(selection_mask, value_mask) → nil

Parameters:

• selection_mask – int
• value_mask – int

Sets the output value (high or low) with a bitmask, according to the selection mask. The bitmask is 4 bit long, true refers to high and false refers to low.

For example: The values 0b0110, 0b0011 will turn pin 2 high and pin 1 low, pin 0 and 3 will remain untouched.

Note

This function does nothing for pins that are configured as input. Pull-up resistors can be switched on with #set_configuration.

New in version 2.0.0 (Plugin).

BrickletIO4#get_api_version → [int, int, int]

Returns the API version (major, minor, revision) of the bindings for this device.

BrickletIO4#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.

BrickletIO4#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 and callbacks it is always disabled.

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:

• BrickletIO4::FUNCTION_SET_VALUE = 1
• BrickletIO4::FUNCTION_SET_CONFIGURATION = 3
• BrickletIO4::FUNCTION_SET_DEBOUNCE_PERIOD = 5
• BrickletIO4::FUNCTION_SET_INTERRUPT = 7
• BrickletIO4::FUNCTION_SET_MONOFLOP = 10
• BrickletIO4::FUNCTION_SET_SELECTED_VALUES = 13

BrickletIO4#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.

BrickletIO4#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 identifiers can be found here.

New in version 2.0.0 (Plugin).

The returned tuple has the values uid, connected_uid, position, hardware_version, firmware_version and device_identifier.

Callback Configuration Functions

BrickletIO4#register_callback(id) { |param [, ...]| block } → nil

Parameters:id – int

Registers a callback with ID id to the given block. The available IDs with corresponding function signatures are listed below.

BrickletIO4#set_debounce_period(debounce) → nil

Parameters:debounce – int

Sets the debounce period of the ::CALLBACK_INTERRUPT callback in ms.

For example: If you set this value to 100, you will get the interrupt maximal every 100ms. This is necessary if something that bounces is connected to the IO-4 Bricklet, such as a button.

The default value is 100.

BrickletIO4#get_debounce_period → int

Returns the debounce period as set by #set_debounce_period.

BrickletIO4#set_interrupt(interrupt_mask) → nil

Parameters:interrupt_mask – int

Sets the pins on which an interrupt is activated with a bitmask. Interrupts are triggered on changes of the voltage level of the pin, i.e. changes from high to low and low to high.

For example: An interrupt bitmask of 9 will enable the interrupt for pins 0 and 3.

The interrupt is delivered with the callback ::CALLBACK_INTERRUPT.

BrickletIO4#get_interrupt → int

Returns the interrupt bitmask as set by #set_interrupt.

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:

io4.register_callback BrickletIO4::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.

BrickletIO4::CALLBACK_INTERRUPT

Parameters:

• interrupt_mask – int
• value_mask – int

This callback is triggered whenever a change of the voltage level is detected on pins where the interrupt was activated with #set_interrupt.

The values are a bitmask that specifies which interrupts occurred and the current value bitmask.

For example:

• (1, 1) means that an interrupt on pin 0 occurred and currently pin 0 is high and pins 1-3 are low.
• (9, 14) means that interrupts on pins 0 and 3 occurred and currently pin 0 is low and pins 1-3 are high.

BrickletIO4::CALLBACK_MONOFLOP_DONE

Parameters:

• selection_mask – int
• value_mask – int

This callback is triggered whenever a monoflop timer reaches 0. The parameters contain the involved pins and the current value of the pins (the value after the monoflop).

New in version 1.1.1 (Plugin).

Constants

BrickletIO4::DEVICE_IDENTIFIER

This constant is used to identify a IO4 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.