Ruby - HAT Brick

This is the description of the Ruby API bindings for the HAT Brick. General information and technical specifications for the HAT Brick 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).

Sleep

Download (example_sleep.rb)

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

require 'tinkerforge/ip_connection'
require 'tinkerforge/brick_hat'

include Tinkerforge

HOST = 'localhost'
PORT = 4223
UID = 'XXYYZZ' # Change XXYYZZ to the UID of your HAT Brick

ipcon = IPConnection.new # Create IP connection
hat = BrickHAT.new UID, ipcon # Create device object

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

# Turn Raspberry Pi and Bricklets off in 2 seconds for 30 minutes with sleep indicator enabled
hat.set_sleep_mode 2, 1800, true, true, true

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

API

All methods listed below are thread-safe.

Basic Functions

BrickHAT::new(uid, ipcon) → hat
Parameters:
  • uid -- str
  • ipcon -- IPConnection

Creates an object with the unique device ID uid:

hat = BrickHAT.new 'YOUR_DEVICE_UID', ipcon

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

BrickHAT#set_sleep_mode(power_off_delay, power_off_duration, raspberry_pi_off, bricklets_off, enable_sleep_indicator) → nil
Parameters:
  • power_off_delay -- int
  • power_off_duration -- int
  • raspberry_pi_off -- bool
  • bricklets_off -- bool
  • enable_sleep_indicator -- bool

Sets the sleep mode.

Note

Calling this function will cut the Raspberry Pi's power after Power Off Delay seconds. You have to shut down the Operating System yourself, e.g. by calling 'sudo shutdown -h now'.

Parameters:

  • Power Off Delay: Time in seconds before the RPi/Bricklets are powered off.
  • Power Off Duration: Duration in seconds that the RPi/Bricklets stay powered off.
  • Raspberry Pi Off: RPi is powered off if set to true.
  • Bricklets Off: Bricklets are powered off if set to true.
  • Enable Sleep Indicator: If set to true, the status LED will blink in a 1s interval during the whole power off duration. This will draw additional 0.3mA.

Example: To turn RPi and Bricklets off in 5 seconds for 10 minutes with sleep indicator enabled, call (5, 60*10, true, true, true).

This function can also be used to implement a watchdog. To do this you can write a program that calls this function once per second in a loop with (10, 2, true, false, false). If the RPi crashes or gets stuck the HAT will reset the RPi after 10 seconds.

BrickHAT#get_sleep_mode → [int, int, bool, bool, bool]

Returns the sleep mode settings as set by #set_sleep_mode.

The returned array has the values power_off_delay, power_off_duration, raspberry_pi_off, bricklets_off and enable_sleep_indicator.

BrickHAT#set_bricklet_power(bricklet_power) → nil
Parameters:bricklet_power -- bool

Set to true/false to turn the power supply of the connected Bricklets on/off.

By default the Bricklets are on.

BrickHAT#get_bricklet_power → bool

Returns the power status of the connected Bricklets as set by #set_bricklet_power.

BrickHAT#get_voltages → [int, int]

Returns the USB supply voltage and the DC input supply voltage in mV.

There are three possible combinations:

  • Only USB connected: The USB supply voltage will be fed back to the DC input connector. You will read the USB voltage and a slightly lower voltage on the DC input.
  • Only DC input connected: The DC voltage will not be fed back to the USB connector. You will read the DC input voltage and the USB voltage will be 0.
  • USB and DC input connected: You will read both voltages. In this case the USB supply will be without load, but it will work as backup if you disconnect the DC input (or if the DC input voltage falls below the USB voltage).

The returned array has the values voltage_usb and voltage_dc.

Advanced Functions

BrickHAT#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.

BrickHAT#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.

BrickHAT#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:

  • BrickHAT::FUNCTION_SET_SLEEP_MODE = 1
  • BrickHAT::FUNCTION_SET_BRICKLET_POWER = 3
  • BrickHAT::FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickHAT::FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickHAT::FUNCTION_RESET = 243
  • BrickHAT::FUNCTION_WRITE_UID = 248
BrickHAT#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.

BrickHAT#get_spitfp_error_count → [int, int, int, int]

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 values error_count_ack_checksum, error_count_message_checksum, error_count_frame and error_count_overflow.

BrickHAT#set_bootloader_mode(mode) → int
Parameters:mode -- int

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:

  • BrickHAT::BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickHAT::BOOTLOADER_MODE_FIRMWARE = 1
  • BrickHAT::BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickHAT::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickHAT::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BrickHAT::BOOTLOADER_STATUS_OK = 0
  • BrickHAT::BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickHAT::BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickHAT::BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickHAT::BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickHAT::BOOTLOADER_STATUS_CRC_MISMATCH = 5
BrickHAT#get_bootloader_mode → int

Returns the current bootloader mode, see #set_bootloader_mode.

The following constants are available for this function:

  • BrickHAT::BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickHAT::BOOTLOADER_MODE_FIRMWARE = 1
  • BrickHAT::BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickHAT::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickHAT::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
BrickHAT#set_write_firmware_pointer(pointer) → nil
Parameters:pointer -- int

Sets the firmware pointer for #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.

BrickHAT#write_firmware(data) → int
Parameters:data -- [int, int, ..61x.., int]

Writes 64 Bytes of firmware at the position as written by #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.

BrickHAT#set_status_led_config(config) → nil
Parameters:config -- int

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:

  • BrickHAT::STATUS_LED_CONFIG_OFF = 0
  • BrickHAT::STATUS_LED_CONFIG_ON = 1
  • BrickHAT::STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickHAT::STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickHAT#get_status_led_config → int

Returns the configuration as set by #set_status_led_config

The following constants are available for this function:

  • BrickHAT::STATUS_LED_CONFIG_OFF = 0
  • BrickHAT::STATUS_LED_CONFIG_ON = 1
  • BrickHAT::STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickHAT::STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickHAT#get_chip_temperature → int

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.

BrickHAT#reset → nil

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!

BrickHAT#write_uid(uid) → nil
Parameters:uid -- int

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.

BrickHAT#read_uid → int

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

BrickHAT#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 Brick.

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

Constants

BrickHAT::DEVICE_IDENTIFIER

This constant is used to identify a HAT Brick.

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.

BrickHAT::DEVICE_DISPLAY_NAME

This constant represents the human readable name of a HAT Brick.