Darth-Vader-RPi’s documentation

🚧    Work-In-Progress

Darth-Vader-RPi (0.1.0a0) is a Python-based Raspberry Pi project about activating a Darth Vader action figure by turning on LEDs on his suit and lightsaber, and by playing sounds such as some of his famous quotes. See the README for more info about the project.

Turning on/off the lightsaber

README

🚧    Work-In-Progress

Darth-Vader-RPi (0.1.0a0) is a Python-based Raspberry Pi (RPi) project about activating a Darth Vader action figure by turning on LEDs on his suit and lightsaber, and by playing sounds such as some of his famous quotes.

Important

If you don’t have an RPi, don’t worry. You can still test the script on your own computer because the darth_vader_rpi package uses the SimulRPi library to simulate I/O devices connected to an RPi such as LEDs and push buttons by blinking red dots in the terminal and playing sounds when a keyboard key is pressed. Almost like testing with a real RPi!

Disclaimer: I also wrote the SimulRPi library

Introduction

The Darth Vader action figure is 11.5 inches tall (which is this one from Hasbro) and was modified to make it more lifelike by illuminating the lightsaber, chest control box, and belt. 3 push buttons control the following sounds and LEDs:

1. Some of his famous quotes

2. The Imperial march theme song

3. The lightsaber drawing, hum and retraction sounds

4. The lightbsaber illumination (3 LEDs)

His iconic breathing sound plays in the background indefinitely almost as soon as the RPi is run with the start_dv script.

Click on the above image for the full video to see the LEDs turning on and hear the different sounds produced by pressing the push buttons

Connection diagram

Here’s how the various LEDs and push buttons are connected to the Raspberry Pi:

• The lightsaber is illuminated by 3 LEDs connected in parallel

• The Top, Middle, and Bottom LEDs illuminate the slots in Darth Vader’s chest control box. They blink in a specific sequence as specified in the configuration file.

• When the Lightsaber button is first pressed, it produces the drawing sound, illuminates the sword, and a hum sound persists until the Lightsaber button is turned off. If the button is pressed again, it produces the sound of retracting the lightsaber and turns it off.

  NOTE: the Lightsaber button can be pressed while the Song button or the Quotes button is playing audio since they use different audio channels.

• The Song button plays the Imperial March song by Jacob Townsend

• The Quotes button plays famous Darth Vader quotes when pressed. For testing purposes, the darth_vader_rpi package comes with two movie lines:

  • “I am your father”

  • “Nooooo”: it is also used for the closing sound when the start_dv script exits

  However, you could add more quotes if you want.

Dependencies

• Platforms: macOS, Linux

• Python: 3.5, 3.6, 3.7, 3.8

• Packages

  • dv_sounds>=0.1.0a0: for retrieving the sound files (quotes, songs, and sound effects)

    • Ref: dv_sounds

  • pygame>=1.9.3: for playing sounds

    • Ref: pygame

  • pynput>=1.6.8: needed by SimulRPi for monitoring the keyboard when simulating push buttons with keyboard keys, i.e. when running the start_dv script in simulation mode

    • Ref: pynput

  • SimulRPi >=0.1.0a0: for partly faking RPI.GPIO and simulating I/O devices connected to an RPi such as LEDs and push buttons in case that you don’t have access to an RPi

    • Ref: SimulRPi

Important

At the time of this writing (2020-08-28), I couldn’t install pygame 1.9.6 (the latest stable release) with Python 3.5 and 3.8, on macOS. However, the latest pre-release development version (2.0.0.dev10) worked well with Python 3.5 and 3.8, on macOS.

Installation instructions

1. Make sure to update pip:

   $ pip install --upgrade pip
   

2. Install the package darth_vader_rpi (latest release) with pip:

   $ pip install git+https://github.com/raul23/Darth-Vader-RPi@v0.1.0a0#egg=Darth-Vader-RPi
   

   It will install the dependencies if they are not already found in your system.

Important

Make sure that pip is working with the correct Python version. It might be the case that pip is using Python 2.x You can find what Python version pip uses with the following:

$ pip -V

If pip is working with the wrong Python version, then try to use pip3 which works with Python 3.x

Note

To install the bleeding-edge version of the darth_vader_rpi package:

$ pip install git+https://github.com/raul23/Darth-Vader-RPi#egg=Darth-Vader-RPi

However, this latest version is not as stable as the released version but you get the latest features being implemented.

Warning message

If you get the warning message from pip that the start_dv script is not defined in your PATH:

WARNING: The script start_dv is installed in '/home/pi/.local/bin' which is not on PATH.

Add the directory mentioned in the warning to your PATH by editing your configuration file (e.g. .bashrc). See this article on how to set PATH on Linux and macOS.

Test installation

1. Test your installation by importing darth_vader_rpi and printing its version:

   $ python -c "import darth_vader_rpi; print(darth_vader_rpi.__version__)"
   

2. You can also test that the dependencies were installed correctly:

   $ python -c "import dv_sounds, pygame, pynput, SimulRPi"
   

Usage

Script start_dv

Once the darth_vader_rpi package is installed, you should have access to the start_dv script which turns on LEDs and plays sound effects on a Raspberry Pi (RPi).

Run the script on your RPi with default values for the GPIO channels and other settings:

$ start_dv

If you want to test the script on your computer (use the -s flag):

$ start_dv -s

Note

Both previous commands will use the default values from the configuration file (e.g GPIO channel numbers, channel volume).

Check Change default settings on how to modify these values.

Important

In order to stop the start_dv script at any moment, press ctrl + c.

List of options

To display the script’s list of options and their descriptions:

$ start_dv -h

--version

show program’s version number and exit

-q, --quiet

Enable quiet mode, i.e. nothing will be printed. (default: False)

-s, --simulation

Enable simulation mode, i.e. SimulRPi.GPIO will be used for simulating RPi.GPIO. (default: False)

-v, --verbose

Print various debugging information, e.g. print traceback when there is an exception. (default: False)

Edit a configuration file:

-e cfg_name, --edit cfg_name

Edit a configuration file. Provide log_cfg for the logging config file or cfg for the main config file. (default: None)

-a APP, --app-name APP

Name of the application to use for editing the file. If no name is given, then the default application for opening this type of file will be used. (default: None)

Simulating on your computer

If you don’t have access to a Raspberry Pi (RPi) and want to try out the start_dv script, you can run it with the -s flag. It will make use of the SimulRPi library to simulate LEDs and push buttons connected to an RPi by blinking red dots in the terminal and monitoring pressed keyboard keys:

$ start_dv -s

NOTE: the last command makes use of default values. See Change default settings on how to change these values.

Here’s how the keyboard keys are related by default to push buttons connected to an RPi:

• cmd_l —–> lightsaber button

• alt_l —–> song button

• alt_r —–> quotes button

Check Change keymap if you want to change this default key-to-channel mapping.

Here is a video of what it looks like in a terminal when running the start_dv script on a computer instead of an RPi:

Click on the above image for the full video

How to uninstall

To uninstall only the package darth_vader_rpi:

$ pip uninstall darth_vader_rpi

To uninstall the package darth_vader_rpi and its dependencies:

$ pip uninstall darth_vader_rpi dv_sounds pygame pynput simulrpi

You can remove from the previous command-line those dependencies that you don’t want to uninstall.

Note

When uninstalling the darth_vader_rpi package, you might be informed that the configuration files logging_cfg.json and main_cfg.json won’t be removed by pip. You can remove those files manually by noting their paths returned by pip. Or you can leave them so your saved settings can be re-used the next time you re-install the package.

Example:

$ pip uninstall darth-vader-rpi
Found existing installation: Darth-Vader-RPi 0.1.0a0
Uninstalling Darth-Vader-RPi-0.1.0a0:
  Would remove:
    /Users/test/miniconda3/envs/rpi_py37/bin/start_dv
    /Users/test/miniconda3/envs/rpi_py37/lib/python3.7/site-packages/Darth_Vader_RPi-0.1.0a0.dist-info/*
    /Users/test/miniconda3/envs/rpi_py37/lib/python3.7/site-packages/darth_vader_rpi/*
  Would not remove (might be manually added):
    /Users/test/miniconda3/envs/rpi_py37/lib/python3.7/site-packages/darth_vader_rpi/configs/logging_cfg.json
    /Users/test/miniconda3/envs/rpi_py37/lib/python3.7/site-packages/darth_vader_rpi/configs/main_cfg.json
$ rm -r /Users/test/miniconda3/envs/rpi_py37/lib/python3.7/site-packages/darth_vader_rpi

Credits

• Darth Vader quotes:

  • “I am your father”

  • “Nooooo”

• Music:

  • Imperial March song by Jacob Townsend is licensed under a Creative Commons (CC BY-NC-SA 3.0) License

    NOTE: The original song file was reduced under 1 MB by removing the first 7 seconds (no sound) and the last 2 minutes and 24 seconds.

• Sound effects:

  • Darth Vader breathing sound

  • Darth Vader’s lightsaber sound effect

  • Darth Vader’s lightsaber retraction sound effect

• Slot LEDs sequences:

  • Empire Strikes Back chest box light sequence

Resources

• Darth-Vader-RPi GitHub: source code

References

• dv_sounds: a package for downloading the various sounds needed for the project, e.g. ligthsaber sound effects

• pygame: a package used for playing sounds

• RPI.GPIO: a module to control RPi GPIO channels

• SimulRPi: a package that partly fakes RPi.GPIO and simulates some I/O devices on a Raspberry Pi. It makes use of the pynput library for monitoring the keyboard for any pressed key.

The main configuration file

The default settings used by the start_dv script are found in the main configuration file. It is referred to as main because there is another config file you could edit, the logging configuration file.

The main configuration file can be edited with the following command:

$ start_dv -e cfg

The logging configuration file could be instead edited with the -e log_cfg command-line option.

The previous command will open the configuration file with the default text editor that is associated with JSON files as specified in your system, e.g. atom on macOS or vim on Linux.

If you want to use another text editor you can specify it with the -a APP command-line option:

$ start_dv -e cfg -a TextEdit

In what follows, you wil find an explanation for each setting found in the main configuration file, presented in alphabetic order.

Important

Some of the settings (quiet, simulation, and verbose) in the configuration file can be also set through the script’s command-line arguments. The command-line arguments override the settings found in the configuration file.

See also

The script start_dv

audio_channels

Three audio channels are used for this project:

• channel 0: used for Darth Vader’s breathing sound which plays in the background almost as soon as the start_dv script runs. Its volume is set by default at 0.2 since we don’t want to overwhelm the other sounds playing in the other audio channels

• channel 1: used for playing the Imperial March song and all Darth Vader quotes. Its volume is set by default at 1.0

• channel 2: used for playing the lighsaber sound effects and the closing sound. Its volume is set by default at 1.0

The setting audio_channels in the configuration file defines these three audio channels with their default volume.

Audio channels and their default volume

"audio_channels": [
  {
    "channel_id": 0,
    "channel_name": "breathing_sound",
    "volume": 0.2
  },
  {
    "channel_id": 1,
    "channel_name": "song_and_quotes",
    "volume": 1.0
  },
  {
    "channel_id": 2,
    "channel_name": "lightsaber_and_closing_sounds",
    "volume": 1.0
  }
],

The Python package pygame is used for playing the various sounds used in this project.

Note

• Volume takes values in the range 0.0 to 1.0 (inclusive).

• If value < 0.0, the volume will not be changed

• If value > 1.0, the volume will be set to 1.0

As per the pygame documentation.

default_led_symbols

The setting default_led_symbols in the configuration file defines the default LED symbols used by all output channels. A LED symbol is used for each output state (ON and OFF).

By default, the symbols used for representing LEDs in the terminal are the following:

"default_led_symbols": {
  "ON": "🛑",
  "OFF": "⚪"
},

See also

Change LED symbols

gpio_channels

The setting gpio_channels in the configuration file defines the GPIO pins connected to LEDs and push buttons.

GPIO channels for the following I/O devices are defined:

• Lightsaber button: it controls the LEDs and sound effects for the lightsaber

• Song button: when pressed it plays the Imperial March song

• Quotes button: when pressed it plays one of Darth Vader quotes

• Slot LEDs: they consist of three LEDs referred to as Top, Middle, and Bottom LEDs and are found on Darth Vader’s chest control box

• Lightsaber LEDs: when the lightsaber button is pressed, these LEDs are turned ON/OFF

  NOTE: on the Darth Vader’s figurine, three LEDs are used to turn on the lightsaber as explained in the Connection diagram. However, when simulating the Raspberry Pi with SimulRPi, only one LED is shown in the terminal

gpio_channels lists GPIO channel objects with the following properties:

• channel_id: this property should not be modified because it is used to uniquely identify the GPIO channels

• channel_name: it will be displayed in the terminal along with the LED symbol. By default, the channel number is displayed if channel_name is the empty string, i.e. channel_name = ""

• channel_number: it identifies the GPIO pin based on the numbering system you have specified (BOARD or BCM)

• key: it is only defined for button objects. It specifies the mapping between a keyboard key and a push button so you can simulate push buttons with your keyboard

  Example: changing keymap for the Song button

   {
     "channel_id": "song_button",
     "channel_name": "song_button",
     "channel_number": 24,
     "key": "shift_r"
   }
  

• led_symbols: it is only defined for LED objects. It is a dictionary defining the symbols to be used when the LED is turned ON and OFF. If not found for a LED object, then the default LED symbols will be used

  Example: changing the default LED symbols for the lightsaber LEDs

   {
     "channel_id": "lightsaber_led",
     "channel_name": "lightsaber",
     "channel_number": 22,
     "led_symbols": {
       "ON": "\\033[1;31;48m(0)\\033[1;37;0m",
       "OFF": "(0)"
     }
   }
  

Let’s take a look at two GPIO channels found in the configuration file:

Example: GPIO channels for the lightsaber button and LEDs

"gpio_channels": [
  {
    "channel_id": "lightsaber_button",
    "channel_name": "lightsaber_button",
    "channel_number": 23,
    "key": "cmd"
  },
  {
    "channel_id": "lightsaber_led",
    "channel_name": "lightsaber",
    "channel_number": 22
  }
]

Thus, in this example, you have a push button connected to the GPIO pin 23 (based on the BCM mode), controlling the lightsaber by turning it ON/OFF and producing the lightsaber sound effects (drawing, retraction, and hum sounds). Also, the keyboard key cmd simulates the lightsaber push button when running the start_dv script on your computer.

Finally, the ligthsaber LEDs are connected to GPIO pin 22 (BCM) and are turned ON/OFF when the corresponding push button (or cmd key) is pressed.

See also

• Change GPIO channel name and number

• Change keymap

• Change LED symbols

mode

The setting mode in the configuration file defines the numbering system (BOARD or BCM) used to identify the GPIO channels. By default, BCM is used.

As per the RPIO.GPIO documentation:

BOARD refers to the pin numbers on the P1 header of the Raspberry Pi board. The advantage of using this numbering system is that your hardware will always work, regardless of the board revision of the RPi. You will not need to rewire your connector or change your code.

BCM is a lower level way of working - it refers to the channel numbers on the Broadcom SOC. You have to always work with a diagram of which channel number goes to which pin on the RPi board. Your script could break between revisions of Raspberry Pi boards.

quiet

The setting quiet in the configuration file is a flag (set to false by default) that allows you to run the start_dv script without printing anything on the terminal, not even the LED symbols when running the simulation nor the exceptions are printed.

However, you will still be able to hear sounds and interact with the push buttons or keyboard.

The setting quiet set to false by default

{
  "quiet": false,
  "simulation": false,
  "verbose": false,
  "mode": "BCM"
}

This flag can also be set directly through the script’s -q command-line option:

$ start_dv -q

See also

Script’s list of options

quotes

The setting quotes in the configuration file defines all the Darth Vader’s quotes used for this project.

By default, two movie lines are included:

• “I am your father”

• “Nooooo”

Each quote is represented in the configuration file as objects having the following properties:

• id: unique identifier

• name: it will be displayed in the terminal

• filename: it is relative to the directory sounds_directory

• audio_channel_id: all quotes should be played in channel 1 as explained in audio_channels

Example: two Darth Vader quotes

 "quotes": [
   {
     "id": "dont_make_me_destroy_you",
     "name": "Don't make me destroy you",
     "filename": "quote_dont_make_me_destroy_you.ogg",
     "audio_channel_id": 1
   },
   {
     "id": "give_yourself_to_the_dark_side",
     "name": "Give yourself to the dark side",
     "filename": "quote_give_yourself_to_the_dark_side.ogg",
     "audio_channel_id": 1
   }
 ]

Important

All Darth Vader quotes should be played in channel 1 as explained in audio_channels

See also

• The setting audio_channels

• Add Darth Vader quotes

• Change channel volume

• Change paths to audio files

simulation

The setting simulation in the configuration file is a flag (set to false by default) that allows you to run the start_dv script on your computer, instead of a Raspberry Pi (RPi).

The SimulRPi.GPIO module is used in order to partly fake RPi.GPIO and simulate I/O devices connected to an RPi such as LEDs and push buttons by displaying LED symbols in the terminal and monitoring the keyboard for any pressed key.

This flag can also be set directly through the script’s -s command-line option:

$ start_dv -s

Note

SimulRPi.GPIO makes use of the pynput package to monitor the keyboard for any pressed key.

See also

Script’s list of options

slot_leds

Three LEDs (labeled as top, middle, and top) illuminate the slots in Darth Vader’s chest control box.

The setting slot_leds in the configuration file defines the sequence the slot LEDs should be turned ON/OFF. This sequence corresponds to Darth Vader’s physiological state, e.g. if he is in a calm mood the slot LEDs will blink in a different pattern than if he was in action.

slot_leds is an object that takes the following properties:

• delay_between_steps: delay in seconds between each step in the sequence

• time_per_step: time in seconds each step will last

• sequence: the type of the sequence which can be either “action”, “calm” or a custom sequence. The sequence will keep on repeating until the script exits

Example: a slot_leds object with the calm sequence

   "slot_leds":{
     "delay_between_steps": 0.5,
     "time_per_step": 1,
     "sequence": "calm"
   },

The user can also provide its own sequence by using a list of LED labels {‘top’, ‘middle’, ‘bottom’} arranged in a sequence specifying the order the slot LEDs should turn ON/OFF.

Example: custom slot LEDs sequence

"sequence":[
  ["top", "bottom"],
  [],
  ["middle"],
  []
]

This simple sequence will turn ON/OFF the slot LEDs in this order:

1. top + bottom LEDs turned ON
2. All LEDs turned OFF
3. middle LED turned ON
4. All LEDs turned OFF

Each step in the sequence will lasts for time_per_step seconds and there will be a delay of delay_between_steps seconds between each step in the sequence. And the whole sequence will keep on repeating until the script exits.

Note

This is how the action and calm sequences are exactly defined:

Action sequence

"sequence":[
  ["top", "middle", "bottom"],
  ["top", "bottom"],
  ["top", "middle", "bottom"],
  ["top"],
  [],
  ["top", "middle", "bottom"],
  ["top"],
  ["top", "middle", "bottom"],
  ["middle", "bottom"],
  [],
  ["top", "bottom"],
  ["top", "middle", "bottom"],
  ["top", "bottom"],
  [],
  ["top"],
  []
]

Calm sequence

"sequence":[
  ["middle"],
  ["top"],
  ["middle"],
  ["top"],
  ["middle"],
  ["top"],
  ["top"],
  [],
  ["bottom"],
  []
]

Note

The default sequences of slot LEDs were obtained from this YouTube video: Empire Strikes Back chest box light sequence.

See also

Change slot LEDs sequence

songs

The setting songs in the configuration file defines the songs that can be played as part of the project.

At the moment, only the Imperial March song by Jacob Townsend is supported.

The setting songs takes a list of song objects having the following properties:

• id: this property should not be modified because it is used to uniquely identify the songs

• name: the name of the song which will be shown in the terminal

• filename: it is relative to the directory sounds_directory

• audio_channel_id: all songs should be played in channel 1 as explained in audio_channels

The Imperial March song playing in audio channel #1

   "songs": [
     {
       "id": "imperial_march_song",
       "name": "Imperial March song",
       "filename": "song_the_imperial_march.ogg",
       "audio_channel_id": 1
     }
   ],

Important

All songs should be played in channel 1 as explained in audio_channels

See also

• The setting audio_channels

• Change channel volume

• Change paths to audio files

sound_effects

The setting sound_effects in the configuration file defines the following sounds:

• Breathing sound: almost as soon as the start_dv script runs, Darth Vader’s breathing sound starts playing in the background until the script ends

• Lightsaber drawing sound: when the lightsaber button is pressed, the drawing sound is played first followed by the hum sound which goes on until the button is pressed again which will produce the retraction sound

• Lightsaber hum sound: plays immediately after the lightsaber drawing sound and goes on until the lightsaber button is pressed again

• Lightsaber retraction sound: plays when the lightsaber button is pressed while the hum sound is playing

• Closing sound: plays after the user presses ctrl + c to exit from the script. By default, it is not played at the end

sound_effects takes a list of sound objects having the following properties:

• id: this property should not be modified because it is used to uniquely identify the sound effects

• name: it is the name of the sound which will be displayed in the terminal

• filename: it is relative to the directory sounds_directory

• audio_channel_id: the audio channel used for playing the sound. See audio_channels to know what channel is used for each type of sounds

• mute: it is only defined for the breathing and closing sounds. If set to true, the sound will not be played

• loops: only defined for the breathing sound. It is the number of times the sound should be repeated. If set to -1, it will be repeated indefinitely

Example: two sound effects playing in different audio channels

   "sound_effects": [
     {
       "id": "breathing_sound",
       "name": "Breathing sound",
       "filename": "darth_vader_breathing.ogg",
       "audio_channel_id": 0,
       "mute": false,
       "loops": -1
     },
     {
       "id": "closing_sound",
       "name": "Nooooo [Closing]",
       "filename": "quote_nooooo.ogg",
       "audio_channel_id": 2,
       "mute": true
     }
   ]

Important

The breathing sound should use channel 0, while the other sound effects should use channel 2. Hence, the breathing sound can be heard in the background while a sound effect is also being played (e.g. the drawing sound of the lightsaber). See audio_channels.

See also

• The setting audio_channels

• Change closing sound

• Change paths to audio files

• Mute breathing sound

sounds_directory

The setting sounds_directory in the configuration file defines the directory where all the audio files are saved.

By default, sounds_directory points to the path where the dv_sounds package is installed. dv_sounds is used to download the various sounds (e.g. sound efffects) needed for the project.

All the audio filenames found in the configuration file are defined relative to sounds_directory.

Example: Filename for the breathing-sound audio file

"sound_effects": [
  {
    "id": "breathing_sound",
    "name": "Breathing sound",
    "filename": "darth_vader_breathing.ogg",
    "audio_channel_id": 0,
    "mute": false,
    "loops": -1
  }
]

In this example, the audio file darth_vader_breathing.ogg is to be found in the directory sounds_directory.

See also

Change paths to audio files

verbose

The setting verbose in the configuration file is a flag (set to false by default) that allows you to run the start_dv script by logging to the terminal all messages (logging level is set to DEBUG when verbose is true). Also, when there is an exception, a traceback is printed so you can pinpoint exactly where the error occurred in the code which is not the case when running the script without verbose (you only get a one-line error message).

Example: running the script without verbose

ERROR    AttributeError: 'Namespace' object has no attribute 'edits'
ERROR    Program exited with 1

Example: running the script with verbose

ERROR    'Namespace' object has no attribute 'edits'
Traceback (most recent call last):
  File "start_dv.py", line 795, in main
    if args.edits:
AttributeError: 'Namespace' object has no attribute 'edits'
ERROR    Program exited with 1

This flag can also be set directly through the script’s -v command-line option:

$ start_dv -v

See also

Script’s list of options

Change the default settings

Important tips

• This is the command to edit the configuration file with a default text editor as defined in your system:

  $ start_dv -e cfg
  

  Or with a specific text editor:

  $ start_dv -e cfg -a APP_NAME
  

  where APP_NAME is the name of a text editor, e.g. TextEditor

• To end the start_dv script, press ctrl + c

• When adding audio files, don’t use mp3 as the file format. Instead, use ogg (compressed) or wav (uncompressed). The reason is that mp3 won’t work well with pygame’s simultaneous playback capability.

  Reference: stackoverflow

Add Darth Vader quotes

If you want to add more Darth Vader quotes, you have to edit the setting quotes in the configuration file. Open the configuration file with:

$ start_dv -e cfg

Each quote is represented in the configuration file as objects having the following properties:

• id: unique identifier

• name: it will be displayed in the terminal

• filename: it is relative to the directory sounds_directory

• audio_channel_id: all quotes should be played in channel 1 as explained in audio_channels

Add your quote object to the list in quotes, like in the following example:

Example: adding a new quote

"quotes": [
  {
    "id": "there_is_no_escape",
    "name": "There is no escape",
    "filename": "quote_there_is_no_escape.ogg",
    "audio_channel_id": 1
  },

See also

• The setting audio_channels

• The setting quotes

• Change channel volume

• Change paths to audio files

Change channel volume

To change the volume for an audio channel, open the configuration file and edit the channel’s volume found in the setting audio_channels:

$ start_dv -e cfg

Audio channels and their default volume

"audio_channels": [
  {
    "channel_id": 0,
    "channel_name": "breathing_sound",
    "volume": 0.2
  },
  {
    "channel_id": 1,
    "name": "song_and_quotes",
    "volume": 1.0
  },
  {
    "channel_id": 2,
    "name": "lightsaber_and_closing_sounds",
    "volume": 1.0
  }
],

What each channel controls:

• Channel 0 controls Darth Vader’s breathing sound

• Channel 1 controls the Imperial March song and all Darth Vader quotes

• Channel 2 controls the lighsaber sound effects and the closing sound

Note

Volume takes values in the range 0.0 to 1.0 (inclusive). As per the pygame documentation.

See also

The setting audio_channels

Change closing sound

When the start_dv script is exiting after the user presses ctrl + c, a sound is produced. By default, no closing sound is produced and if it were to play, it would be the “Nooooo” quote.

To change the default closing sound, edit the setting sound_effects in the configuration file which can be opened with:

$ start_dv -e cfg

At the end of the list in sound_effects, you will find the closing_sound object. These are the properties you can modify for this object:

• name: it is the name of the sound which will be displayed in the terminal

• filename: it is relative to sounds_directory

• mute: if true, nothing will be played at the end of the script. Otherwise, the closing sound will be played when the script is terminating.

Example: choosing another closing sound by changing filename

"sound_effects": [
  {
    "id": "closing_sound",
    "name": "Bye [Closing]",
    "filename": "bye.ogg",
    "audio_channel_id": 2,
    "mute": false
  },

Note

By default, the closing sound is not played at the end of the start_dv script. Set its property mute to true in order to play the closing sound when the script exits.

See also

• The setting audio_channels

• The setting sound_effects

• Change channel volume

• Change paths to audio files

Change GPIO channel name and number

The GPIO channels are identified in the terminal by their channel_name along with their LED symbols. If channel_name is not available, then its channel_number is shown.

The channel_number is the GPIO channel number of a pin used for connecting an I/O device (e.g. LED) and is defined based on the numbering system you have specified (BOARD or BCM).

To change a GPIO channel’s channel_name and channel_number, open the configuration file with:

$ start_dv -e cfg

And edit its properties channel_name and channel_number, like in the following example.

Example: changing the channel_name and channel_number for the bottom LED

"gpio_channels": [
  {
    "channel_id": "bottom_led",
    "channel_name": "Bottom LED",
    "channel_number": 15
  },

Important

Don’t change the property channel_id since it is used to uniquely identify the GPIO channels.

See also

The setting gpio_channels

Change keymap

If you want to change the default keymap used for the three push buttons, edit the setting gpio_channels in the configuration file which can be opened with:

$ start_dv -e cfg

Default keymap used for the three push buttons

"gpio_channels": [
  {
    "channel_id": "lightsaber_button",
    "channel_name": "lightsaber_button",
    "channel_number": 23,
    "key": "cmd"
  },
  {
    "channel_id": "song_button",
    "channel_name": "song_button",
    "channel_number": 24,
    "key": "alt"
  },
  {
    "channel_id": "quotes_button",
    "channel_name": "quotes_button",
    "channel_number": 25,
    "key": "alt_r"
  },

In order to change the default keymap, you will need to change the value for key which refers to the name of the keyboard key associated with a given push button.

The names of keyboard keys that you can use are those specified in the SimulRPi’s documentation, e.g. media_play_pause, shift, and shift_r.

Example: choosing shift_r for the Quotes button

{
  "channel_id": "quotes_button",
  "channel_name": "quotes_button",
  "channel_number": 25,
  "key": "shift_r"
},

Note

On mac, I recommend using the following keyboard keys because they don’t require running the start_dv script with sudo: alt, alt_r, cmd, cmd_r, ctrl, ctrl_r, media_play_pause, media_volume_down, media_volume_mute, media_volume_up, shift, and shift_r.

Ref.: Platform limitations

See also

The setting gpio_channels

Change LED symbols

You can either:

1. change the default LED symbols used by all output channels, or

2. change the LED symbols for specific output channels

Case 1: change default_led_symbols

To change the default LED symbols used by all output channels, edit the setting default_led_symbols by opening the configuration file:

$ start_dv -e cfg

Add your LED symbols for each output state:

"default_led_symbols": {
  "ON": "🔵",
  "OFF": "⚪ "
},

Case 2: change gpio_channels

To change the LED symbols for specific output channels, edit the setting gpio_channels by opening the configuration file:

$ start_dv -e cfg

You need to modify the property led_symbols for a given LED object defined in gpio_channels.

Example: changing the symbols for the lightsaber LED

 "gpio_channels": [
   {
      "channel_id": "lightsaber_led",
      "channel_name": "lightsaber",
      "channel_number": 22,
      "led_symbols": {
        "ON": "\\033[1;31;48m(0)\\033[1;37;0m",
        "OFF": "(0)"️
      }
    }
 ]

Note

If you omit led_symbols as a property for a LED object, the default LED symbols will be used instead.

Important

If you are having problems displaying the default LED symbols when running the start_dv script, such as this error:

ERROR    UnicodeEncodeError: 'ascii' codec can't encode character '\U0001f6d1' in position 2: ordinal not in range(128)

Then, you are might have your locale settings set incorrectly. Check Display problems for more info about how to change them properly or other solutions.

See also

• The setting gpio_channels

• Change slot LEDs sequence

Change paths to audio files

The setting sounds_directory in the configuration file defines the directory where all audio files (e.g. quotes) are saved.

Each audio object defined in the settings quotes, songs and sound_effects have a filename property that you can modify. The filename for each audio file is defined with respect to the directory sounds_directory.

Example: filename for the closing sound

"sound_effects": [
  {
    "id": "closing_sound",
    "filename": "quote_nooooo.ogg",
    "audio_channel_id": 2,
    "mute": false
  },

Important

Don’t change the id property for songs and sound_effects objects because it is used to uniquely identify them.

See also

• The setting quotes

• The setting songs

• The setting sound_effects

• The setting sounds_directory

Change slot LEDs sequence

The setting slot_leds in the configuration file controls the blinking pattern of the three slot LEDs in Darth Vader’s control box.

To change the default sequence, open the configuration file:

$ start_dv -e cfg

The slot_leds object defines the property sequence which can take a string value (‘action’ or ‘calm’) or a custom sequence.

The custom sequence consists of a list of LED labels {‘top’, ‘middle’, ‘bottom’} arranged in a sequence specifying the order the slot LEDs should turn ON/OFF.

Example: a slot_leds object with the calm sequence

   "slot_leds":{
     "delay_between_steps": 0.5,
     "time_per_step": 1,
     "sequence": "calm"
   },

Example: a slot_leds object with a custom sequence

   "slot_leds":{
     "delay_between_steps": 0.5,
     "time_per_step": 1,
     "sequence":[
       ["top", "bottom"],
       [],
       ["middle"],
       []
     ]
   },

This simple custom sequence will turn ON/OFF the slot LEDs in this order:

1. top + bottom LEDs turned ON
2. All LEDs turned OFF
3. middle LED turned ON
4. All LEDs turned OFF

Each step in the sequence will lasts for time_per_step seconds and there will be a delay of delay_between_steps seconds between each step in the sequence. And the whole sequence will keep on repeating until the script exits by pressing ctrl + c.

See also

The setting slot_leds

Mute breathing sound

To mute Darth Vader’s breathing sound which plays almost as soon as the start_dv script runs, edit the setting sound_effects in the configuration file which can be opened with:

$ start_dv -e cfg

Set the breathing_sound object’s mute to false.

Example: Mute the breathing sound

   "sound_effects": [
     {
       "id": "breathing_sound",
       "name": "Breathing sound",
       "filename": "darth_vader_breathing.ogg",
       "audio_channel_id": 0,
       "mute": false,
       "loops": -1
     }
   ]

See also

• The setting sound_effects

• Change channel volume

Run the script as quiet or verbose

To run the start_dv script as quiet or verbose, open the configuration file with:

$ start_dv -e cfg

And set the setting quiet or verbose to true.

When running the start_dv script as verbose, the logging level is set to DEBUG. Thus, all messages will be displayed and when there is an exception, the traceback will be shown.

On the other hand, when running the start_dv script as quiet, nothing will be printed to the terminal, not even error messages. However, you will still be able to hear sounds and interact with the push buttons or keyboard.

Important

if quiet and verbose are both activated at the same time, only quiet will have an effect.

See also

• The setting quiet

• The setting verbose

API Reference

darth_vader_rpi.start_dv

Script to turn on LEDs and play sound effects on a Raspberry Pi (RPi).

The LEDs illuminate a Darth Vader action figure’s lightsaber and the three slots in the chest control box. 3 push buttons control the following sounds and LEDs:

1. Some of his famous quotes

2. The Imperial march theme song

3. The lightsaber drawing, hum and retraction sounds

4. The lightsaber illumination (3 LEDs)

His iconic breathing sound plays in the background indefinitely almost as soon as the RPi is run with the script.

The script allows you also to edit the main config file to setup among other things the RPi’s GPIO pins connected to LEDs and push buttons.

By default the RPi.GPIO module is used, but if the simulation option (-s) is used with the start_dv script, then the SimulRPi.GPIO module will be used instead which simulates RPi.GPIO for those that don’t have an RPi to test on.

Usage

Once the darth_vader_rpi package is installed, you should have access to the start_dv script:

start_dv [-h] [--version] [-q] [-s] [-v] [-e {log,main}] [-a APP]

Run the script on the RPi with default values for the GPIO channels and other settings:

$ start_dv

Run the script on your computer using SimulRPi.GPIO which simulates RPi.GPIO:

$ start_dv -s

Edit the main config file with TextEdit (e.g. on macOS):

$ start_dv -e main -a TextEdit

Edit the logging config file with a default application (e.g. atom):

$ start_dv -e log

Notes

More information is available at:

• Darth-Vader-RPi GitHub

• SimulRPi GitHub

Note

In darth_vader, ledutils, and start_dv, the default value for GPIO is None and will be eventually set to one of the two modules (RPi.GPIO or SimulRPi.GPIO) depending on the user’s settings.

RPi.GPIO provides a class to control the GPIO pins on a Raspberry Pi.

If the simulation option (-s) is used with the start_dv script, the SimulRPi.GPIO module will be used instead.

start_dv.edit_config(cfg_type, app=None)

Edit a configuration file.

The user chooses what type of config file (cfg_type) to edit: ‘log’ for the logging config file and ‘main’ for the main config file.

The configuration file can be opened by a user-specified application (app) or a default program associated with this type of file (when app is None).

Parameters

• cfg_type (str, {'log', 'main'}) – The type of configuration file we want to edit. ‘log’ refers to the logging config file, and ‘main’ to the main config file used to setup the Darth-Vader-RPi project such as specifying the sound effects or the GPIO channels.

• app (str, optional) – Name of the application to use for opening the config file, e.g. TextEdit (the default value is None which implies that the default application will be used to open the config file).

Returns

retcode – If there is a subprocess -related error, the return code is non-zero. Otherwise, it is 0 if the file can be successfully opened with an external program.

Return type

int

start_dv.main()

Main entry-point to the script.

According to the user’s choice of action, the script might:

• activate a Darth Vader figurine (turn on LEDs and play sound effects)

• edit a configuration file

Raises

ValueError – Raised if an invalid configuration name is given to the command-line argument edit.

Notes

Only one action at a time can be performed.

start_dv.setup_argparser()

Setup the argument parser for the command-line script.

The important actions that can be performed with the script are:

• activate a Darth Vader figurine (turn on LEDs and play sound effects)

• edit a configuration file

Returns

parser – Argument parser.

Return type

argparse.ArgumentParser

darth_vader_rpi.darth_vader

Module for activating a Darth Vader figurine by turning on LEDs on his suit and playing sounds, all done via a Raspberry Pi (RPi).

The LEDs illuminate Darth Vader’s lightsaber and the three slots in the chest control box. 3 push buttons control the following sounds and LEDs:

1. Some of his famous quotes

2. The Imperial march theme song

3. The lightsaber drawing, hum and retraction sounds

4. The lightsaber illumination (3 LEDs)

His iconic breathing sound plays in the background indefinitely almost as soon as the RPi is run with the script.

class darth_vader.DarthVader(main_cfg)

Bases: object

Class for activating a Darth Vader figurine by turning on LEDs on his suit and playing sounds, all done via a Raspberry Pi (RPi).

The main config file is used to setup the start_dv script, such as the GPIO pins and the sound files.

Parameters

main_cfg (dict) – Dictionary containing the configuration data to setup the start_dv script, such as the GPIO pins and the sound files. See main config file for a detailed look into its content.

Variables

th_slot_leds (start_dv.ExceptionThread) –

Thread responsible for turning on the three slot LEDs in a precise sequence.

Its target function is ledutils.turn_on_slot_leds().

activate()

Activate a Darth Vader figurine by turning on LEDs on his suit and playing sounds, all done via an RPi.

While the method waits for a pressed button, you can exit by pressing ctr + c.

Returns

retcode – If the method is run without any Exception, the return code is 0. Otherwise, it is 1.

Also, even if there is an Exception, the method will try to clean up before exiting.

Return type

int

cleanup(gpio_channels)

Clean up any resources such as threads and GPIO channels.

The cleanup consists in the following actions:

• turn off each LED

• stop the thread th_slot_leds

• stop each audio channel

• call RPi.GPIO.cleanup() which will return all GPIO channels back to inputs with no pull up/down

  • If in simulation mode, SimulRPi.GPIO.cleanup is called to stop the threads among other things

Parameters

gpio_channels (dict) –

Dictionary mapping channel id (str) to channel attributes (dict). The channel attributes consist in the following:

• channel_number

• channel_name

• key

• led_symbols

Note

These channel attributes are those found in the setting gpio_channels from the main configuration file.

class darth_vader.ExceptionThread(verbose=False, *args, **kwargs)

Bases: threading.Thread

A subclass from threading.Thread that defines threads that can catch errors if their target functions raise an exception.

Parameters

• verbose (bool, optional) – If True, print the traceback when there is an exception. Otherwise, print just a one-line error message, e.g. KeyError: 'test'

• args (tuple, optional) – Positional arguments given to the thread’s target function.

• kwargs (dict, optional) – Keyword arguments given to the thread’s target function.

Variables

exc (Exception) – Represents the exception raised by the target function.

References

• stackoverflow

run()

Method representing the thread’s activity.

Overridden from the base class threading.Thread. This method invokes the callable object passed to the object’s constructor as the target argument, if any, with sequential and keyword arguments taken from the args and kwargs arguments, respectively.

It also saves and logs any error that the target function might raise.

darth_vader_rpi.ledutils

Collection of LEDs-related utilities for the Darth-Vader-RPi project.

ledutils.turn_off_led(channel)

Turn off a LED from a given channel.

Parameters

channel (int) – Channel number associated with a LED which will be turned off.

ledutils.turn_on_led(channel)

Turn on a LED from a given channel.

Parameters

channel (int) – Channel number associated with a LED which will be turned on.

ledutils.turn_on_slot_leds(top_led, middle_led, bottom_led, leds_sequence='action', delay_between_steps=0.5, time_per_step=0.5)

A thread’s target function that turn on/off the three slot LEDs in a precise sequence.

These three LEDs are associated with Darth Vader’s three slots located on his chest control box. These LEDs are labeled as ‘top’, ‘middle’, and ‘bottom’, respectively.

The three LEDs are turned on according to a default or custom sequence which repeats itself. The accepted values for leds_sequence are ‘action’ and ‘calm’ which represent Darth Vader’s physiological state as a sequence of LEDs blinking in a particular order.

The user can also provide its own leds_sequence by using a list of LED labels {‘top’, ‘midddle’, ‘bottom’} arranged in a sequence specifying the order the slot LEDs should turn on/off, e.g. [['top', 'bottom'], [], ['middle'], []] will turn on/off the slot LEDs in this order:

1. top + bottom LEDs turned on
2. All LEDs turned off
3. middle LED turned on
4. All LEDs turned off

Each step in the sequence will last for time_per_step seconds.

There will be a delay of delay_between_steps seconds between each step in the previous example.

The default sequences of slot LEDs were obtained from this YouTube video.

Parameters

• top_led (int) – Channel number associated with the Top slot LED.

• middle_led (int) – Channel number associated with the Middle slot LED.

• bottom_led (int) – Channel number associated with the Bottom slot LED.

• leds_sequence (str or list, optional) –

  Sequence of slot LEDs on Darth Vader’s chest box.

  If leds_sequence is a string, then it takes on one of these values which represent Darth Vader’s physiological state: {‘action’, ‘calm’}.

  If leds_sequence is a list, then it must be a list of slot LED labels {‘top’, ‘middle’, ‘bottom’} arranged in a sequence as to specify the order the slot LEDs should turn on/off, e.g. [['top', 'bottom'], [], ['middle'], []] will turn on/off the slot LEDs in this order:

  1. top + bottom LEDs turn on
  2. All LEDs turn off
  3. middle LED turn on
  4. All LEDs turn off
  

• delay_between_steps (float, optional) – Delay in seconds between each step in the sequence. The default value is 0.5 second.

• time_per_step (float, optional) –

  Time in seconds each step in the sequence will last. The default value is 0.5 second.

  Important

  This also affects the time all LEDs will remain turned off if a step in leds_sequence is an empty list.

Important

turn_on_slot_leds() should be run by a thread and eventually stopped from the main program by setting its do_run attribute to False to let the thread exit from its target function.

For example:

th = threading.Thread(target=turn_on_slot_leds,
                      args=(leds_channels))
th.start()

# Your other code ...

# Time to stop thread
th.do_run = False
th.join()

darth_vader_rpi.utils

Collection of utilities for the Darth-Vader-RPi project.

class utils.SoundWrapper(sound_id, sound_name, sound_filepath, channel_id, mute=False)

Bases: object

Class that wraps around pygame.mixer.Channel and pygame.mixer.Sound.

The __init__ method takes care of automatically loading the sound file. The sound file can then be played or stopped from the specified channel channel_id with the play() or stop() method, respectively.

Parameters

• sound_id (str) – A unique identifier.

• sound_name (str) – Name of the sound file that will be displayed in the terminal.

• sound_filepath (str) – Path to the sound file.

• channel_id (int) – Channel id associated with an instance of pygame.mixer.Channel for controlling playback. It must take an int value starting from 0.

• mute (bool, optional) – If set to True, the sound will not be played. The default value is False.

Note

It is a wrapper with a very minimal interface to pygame.mixer.Channel where only two methods play() and stop() are provided for the sake of the project.

play(loops=0)

Play a sound on the specified Channel channel_id.

Parameters

loops (int) –

Controls how many times the sample will be repeated after being played the first time. The default value (zero) means the sound is not repeated, and so is only played once. If loops is set to -1 the sound will loop indefinitely (though you can still call stop() to stop it).

Reference: pygame.mixer.Sound.play()

stop()

Stop playback on the specified channel channel_id.

utils.add_spaces_to_msg(msg, nb_spaces=60)

Add spaces at the end of a message.

Parameters

• msg (str) – Message to be updated with spaces at the end.

• nb_spaces (int) – Number of spaces to add at the end of the message. The default value is 60.

Returns

message – The updated message with spaces added at the end.

Return type

str

utils.dumps_json(filepath, data, encoding='utf8', ensure_ascii=False, indent=None, sort_keys=False)

Write data to a JSON file.

The data is first serialized to a JSON formatted string and then saved to disk.

Parameters

• filepath (str) – Path to the JSON file where the data will be saved.

• data – Data to be written to the JSON file.

• encoding (str, optional) – Encoding to be used for opening the JSON file in write mode (the default value is ‘utf8’).

• ensure_ascii (bool, optional) – If ensure_ascii is False, then the return value can contain non-ASCII characters if they appear in strings contained in data. Otherwise, all such characters are escaped in JSON strings. See the json.dumps docstring description (the default value is False).

• indent (int or None, optional) – If indent is a non-negative integer, then JSON array elements and object members will be pretty-printed with that indent level. An indent level of 0 will only insert newlines. None is the most compact representation. See the json.dumps() docstring description. (the default value is None).

• sort_keys (bool, optional) – If sort_keys is True, then the output of dictionaries will be sorted by key. See the json.dumps docstring description. (the default value is False).

Raises

OSError – Raised if any I/O related error occurs while writing the data to disk, e.g. the file doesn’t exist.

utils.get_cfg_dirpath()

Get the path to the directory containing the config files.

Returns

dirpath – The path to the directory containing the config files.

Return type

str

utils.get_cfg_filepath(file_type)

Get the path to a config file used by the script start_dv.

file_type accepts the following values:

• default_log: refers to the default logging configuration file used to setup the logging for all custom modules.

• default_main: refers to the default main configuration file used to setup the script start_dv.

• log: refers to the user-defined logging configuration file which is used to setup the logging for all custom modules.

• main: refers to the user-defined main configuration file used to setup the script start_dv.

Parameters

file_type (str, {‘default_log’, ‘default_main’, ‘log’, ‘main’}) – The type of config file for which we want the path.

Returns

filepath – The path to the config file.

Return type

str

Raises

AssertionError – Raised if the wrong type of config file is given to the function. Only {‘default_log’, ‘default_main’, ‘log’, ‘main’} are accepted for file_type.

utils.load_json(filepath, encoding='utf8')

Load JSON data from a file on disk.

If using Python version betwee 3.0 and 3.6 (inclusive), the data is returned as collections.OrderedDict. Otherwise, the data is returned as dict.

Parameters

• filepath (str) – Path to the JSON file which will be read.

• encoding (str, optional) – Encoding to be used for opening the JSON file in read mode (the default value is ‘utf8’).

Returns

data – Data loaded from the JSON file.

Return type

dict or collections.OrderedDict

Raises

OSError – Raised if any I/O related error occurs while reading the file, e.g. the file doesn’t exist.

References

Are dictionaries ordered in Python 3.6+? (stackoverflow)

utils.override_config_with_args(config, parser)

Override a config dictionary with arguments from the command-line.

Parameters

• config (dict) – Dictionary containing configuration options.

• parser (argparse.ArgumentParser) – Argument parser.

Returns

retval – Contains two lists:

1. args_not_found: saves command-line arguments not found in the config dictionary

2. config_opts_overridden: saves config options overridden by command-line arguments as a three-tuple (option name, old value, new value)

Return type

collections.namedtuple

utils.run_cmd(cmd)

Run a shell command with arguments.

The shell command is given as a string but the function will split it in order to get a list having the name of the command and its arguments as items.

Parameters

cmd (str) –

Command to be executed, e.g.

open -a TextEdit text.txt

Returns

retcode – Returns code which is 0 if the command was successfully completed. Otherwise, the return code is non-zero.

Return type

int

Raises

FileNotFoundError – Raised if the command cmd is not recognized, e.g. $ TextEdit {filepath} since TextEdit is not an executable.

Changelog

Version 0.1.0a0

September 15, 2020

• Initial release

• Tested the start_dv script on various platforms and environments.

  Here are the results:

  • macOS:

    • The start_dv -s command runs without errors on Python 3.7 and 3.8

    • On Python 3.5 and 3.6, I had to set my locale settings to LANG="en_US.UTF-8" to make the start_dv -s command work. Thus, it was not an error with the script but with how my system environment was setup. Python 3.5 and 3.6 don’t assume UTF-8 based local settings like the other more recent Python versions.

  • Raspberry Pi (Python 3.5):

    • Running the start_dv command without errors.

    • Running the start_dv -s command without errors.

  • SSH from macOS to RPi (Python 3.5):

    • Running the start_dv command without errors.

    • Running the start_dv -s command produces a warning about pynput not being able to be imported (as expected) but the rest of the code that doesn’t depend on keyboard keys being detected works, i.e. blinking of LED symbols in the terminal.

  Note

  For more detailed information about these tests, check Test results for start_dv

License: GPL3

GNU GENERAL PUBLIC LICENSE
                       Version 3, 29 June 2007

 Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

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software and other kinds of works.

  The licenses for most software and other practical works are designed
to take away your freedom to share and change the works.  By contrast,
the GNU General Public License is intended to guarantee your freedom to
share and change all versions of a program--to make sure it remains free
software for all its users.  We, the Free Software Foundation, use the
GNU General Public License for most of our software; it applies also to
any other work released this way by its authors.  You can apply it to
your programs, too.

  When we speak of free software, we are referring to freedom, not
price.  Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
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want it, that you can change the software or use pieces of it in new
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  To protect your rights, we need to prevent others from denying you
these rights or asking you to surrender the rights.  Therefore, you have
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  For example, if you distribute copies of such a program, whether
gratis or for a fee, you must pass on to the recipients the same
freedoms that you received.  You must make sure that they, too, receive
or can get the source code.  And you must show them these terms so they
know their rights.

  Developers that use the GNU GPL protect your rights with two steps:
(1) assert copyright on the software, and (2) offer you this License
giving you legal permission to copy, distribute and/or modify it.

  For the developers' and authors' protection, the GPL clearly explains
that there is no warranty for this free software.  For both users' and
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  Some devices are designed to deny users access to install or run
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products.  If such problems arise substantially in other domains, we
stand ready to extend this provision to those domains in future versions
of the GPL, as needed to protect the freedom of users.

  Finally, every program is threatened constantly by software patents.
States should not allow patents to restrict development and use of
software on general-purpose computers, but in those that do, we wish to
avoid the special danger that patents applied to a free program could
make it effectively proprietary.  To prevent this, the GPL assures that
patents cannot be used to render the program non-free.

  The precise terms and conditions for copying, distribution and
modification follow.

                       TERMS AND CONDITIONS

  0. Definitions.

  "This License" refers to version 3 of the GNU General Public License.

  "Copyright" also means copyright-like laws that apply to other kinds of
works, such as semiconductor masks.

  "The Program" refers to any copyrightable work licensed under this
License.  Each licensee is addressed as "you".  "Licensees" and
"recipients" may be individuals or organizations.

  To "modify" a work means to copy from or adapt all or part of the work
in a fashion requiring copyright permission, other than the making of an
exact copy.  The resulting work is called a "modified version" of the
earlier work or a work "based on" the earlier work.

  A "covered work" means either the unmodified Program or a work based
on the Program.

  To "propagate" a work means to do anything with it that, without
permission, would make you directly or secondarily liable for
infringement under applicable copyright law, except executing it on a
computer or modifying a private copy.  Propagation includes copying,
distribution (with or without modification), making available to the
public, and in some countries other activities as well.

  To "convey" a work means any kind of propagation that enables other
parties to make or receive copies.  Mere interaction with a user through
a computer network, with no transfer of a copy, is not conveying.

  An interactive user interface displays "Appropriate Legal Notices"
to the extent that it includes a convenient and prominently visible
feature that (1) displays an appropriate copyright notice, and (2)
tells the user that there is no warranty for the work (except to the
extent that warranties are provided), that licensees may convey the
work under this License, and how to view a copy of this License.  If
the interface presents a list of user commands or options, such as a
menu, a prominent item in the list meets this criterion.

  1. Source Code.

  The "source code" for a work means the preferred form of the work
for making modifications to it.  "Object code" means any non-source
form of a work.

  A "Standard Interface" means an interface that either is an official
standard defined by a recognized standards body, or, in the case of
interfaces specified for a particular programming language, one that
is widely used among developers working in that language.

  The "System Libraries" of an executable work include anything, other
than the work as a whole, that (a) is included in the normal form of
packaging a Major Component, but which is not part of that Major
Component, and (b) serves only to enable use of the work with that
Major Component, or to implement a Standard Interface for which an
implementation is available to the public in source code form.  A
"Major Component", in this context, means a major essential component
(kernel, window system, and so on) of the specific operating system
(if any) on which the executable work runs, or a compiler used to
produce the work, or an object code interpreter used to run it.

  The "Corresponding Source" for a work in object code form means all
the source code needed to generate, install, and (for an executable
work) run the object code and to modify the work, including scripts to
control those activities.  However, it does not include the work's
System Libraries, or general-purpose tools or generally available free
programs which are used unmodified in performing those activities but
which are not part of the work.  For example, Corresponding Source
includes interface definition files associated with source files for
the work, and the source code for shared libraries and dynamically
linked subprograms that the work is specifically designed to require,
such as by intimate data communication or control flow between those
subprograms and other parts of the work.

  The Corresponding Source need not include anything that users
can regenerate automatically from other parts of the Corresponding
Source.

  The Corresponding Source for a work in source code form is that
same work.

  2. Basic Permissions.

  All rights granted under this License are granted for the term of
copyright on the Program, and are irrevocable provided the stated
conditions are met.  This License explicitly affirms your unlimited
permission to run the unmodified Program.  The output from running a
covered work is covered by this License only if the output, given its
content, constitutes a covered work.  This License acknowledges your
rights of fair use or other equivalent, as provided by copyright law.

  You may make, run and propagate covered works that you do not
convey, without conditions so long as your license otherwise remains
in force.  You may convey covered works to others for the sole purpose
of having them make modifications exclusively for you, or provide you
with facilities for running those works, provided that you comply with
the terms of this License in conveying all material for which you do
not control copyright.  Those thus making or running the covered works
for you must do so exclusively on your behalf, under your direction
and control, on terms that prohibit them from making any copies of
your copyrighted material outside their relationship with you.

  Conveying under any other circumstances is permitted solely under
the conditions stated below.  Sublicensing is not allowed; section 10
makes it unnecessary.

  3. Protecting Users' Legal Rights From Anti-Circumvention Law.

  No covered work shall be deemed part of an effective technological
measure under any applicable law fulfilling obligations under article
11 of the WIPO copyright treaty adopted on 20 December 1996, or
similar laws prohibiting or restricting circumvention of such
measures.

  When you convey a covered work, you waive any legal power to forbid
circumvention of technological measures to the extent such circumvention
is effected by exercising rights under this License with respect to
the covered work, and you disclaim any intention to limit operation or
modification of the work as a means of enforcing, against the work's
users, your or third parties' legal rights to forbid circumvention of
technological measures.

  4. Conveying Verbatim Copies.

  You may convey verbatim copies of the Program's source code as you
receive it, in any medium, provided that you conspicuously and
appropriately publish on each copy an appropriate copyright notice;
keep intact all notices stating that this License and any
non-permissive terms added in accord with section 7 apply to the code;
keep intact all notices of the absence of any warranty; and give all
recipients a copy of this License along with the Program.

  You may charge any price or no price for each copy that you convey,
and you may offer support or warranty protection for a fee.

  5. Conveying Modified Source Versions.

  You may convey a work based on the Program, or the modifications to
produce it from the Program, in the form of source code under the
terms of section 4, provided that you also meet all of these conditions:

    a) The work must carry prominent notices stating that you modified
    it, and giving a relevant date.

    b) The work must carry prominent notices stating that it is
    released under this License and any conditions added under section
    7.  This requirement modifies the requirement in section 4 to
    "keep intact all notices".

    c) You must license the entire work, as a whole, under this
    License to anyone who comes into possession of a copy.  This
    License will therefore apply, along with any applicable section 7
    additional terms, to the whole of the work, and all its parts,
    regardless of how they are packaged.  This License gives no
    permission to license the work in any other way, but it does not
    invalidate such permission if you have separately received it.

    d) If the work has interactive user interfaces, each must display
    Appropriate Legal Notices; however, if the Program has interactive
    interfaces that do not display Appropriate Legal Notices, your
    work need not make them do so.

  A compilation of a covered work with other separate and independent
works, which are not by their nature extensions of the covered work,
and which are not combined with it such as to form a larger program,
in or on a volume of a storage or distribution medium, is called an
"aggregate" if the compilation and its resulting copyright are not
used to limit the access or legal rights of the compilation's users
beyond what the individual works permit.  Inclusion of a covered work
in an aggregate does not cause this License to apply to the other
parts of the aggregate.

  6. Conveying Non-Source Forms.

  You may convey a covered work in object code form under the terms
of sections 4 and 5, provided that you also convey the
machine-readable Corresponding Source under the terms of this License,
in one of these ways:

    a) Convey the object code in, or embodied in, a physical product
    (including a physical distribution medium), accompanied by the
    Corresponding Source fixed on a durable physical medium
    customarily used for software interchange.

    b) Convey the object code in, or embodied in, a physical product
    (including a physical distribution medium), accompanied by a
    written offer, valid for at least three years and valid for as
    long as you offer spare parts or customer support for that product
    model, to give anyone who possesses the object code either (1) a
    copy of the Corresponding Source for all the software in the
    product that is covered by this License, on a durable physical
    medium customarily used for software interchange, for a price no
    more than your reasonable cost of physically performing this
    conveying of source, or (2) access to copy the
    Corresponding Source from a network server at no charge.

    c) Convey individual copies of the object code with a copy of the
    written offer to provide the Corresponding Source.  This
    alternative is allowed only occasionally and noncommercially, and
    only if you received the object code with such an offer, in accord
    with subsection 6b.

    d) Convey the object code by offering access from a designated
    place (gratis or for a charge), and offer equivalent access to the
    Corresponding Source in the same way through the same place at no
    further charge.  You need not require recipients to copy the
    Corresponding Source along with the object code.  If the place to
    copy the object code is a network server, the Corresponding Source
    may be on a different server (operated by you or a third party)
    that supports equivalent copying facilities, provided you maintain
    clear directions next to the object code saying where to find the
    Corresponding Source.  Regardless of what server hosts the
    Corresponding Source, you remain obligated to ensure that it is
    available for as long as needed to satisfy these requirements.

    e) Convey the object code using peer-to-peer transmission, provided
    you inform other peers where the object code and Corresponding
    Source of the work are being offered to the general public at no
    charge under subsection 6d.

  A separable portion of the object code, whose source code is excluded
from the Corresponding Source as a System Library, need not be
included in conveying the object code work.

  A "User Product" is either (1) a "consumer product", which means any
tangible personal property which is normally used for personal, family,
or household purposes, or (2) anything designed or sold for incorporation
into a dwelling.  In determining whether a product is a consumer product,
doubtful cases shall be resolved in favor of coverage.  For a particular
product received by a particular user, "normally used" refers to a
typical or common use of that class of product, regardless of the status
of the particular user or of the way in which the particular user
actually uses, or expects or is expected to use, the product.  A product
is a consumer product regardless of whether the product has substantial
commercial, industrial or non-consumer uses, unless such uses represent
the only significant mode of use of the product.

  "Installation Information" for a User Product means any methods,
procedures, authorization keys, or other information required to install
and execute modified versions of a covered work in that User Product from
a modified version of its Corresponding Source.  The information must
suffice to ensure that the continued functioning of the modified object
code is in no case prevented or interfered with solely because
modification has been made.

  If you convey an object code work under this section in, or with, or
specifically for use in, a User Product, and the conveying occurs as
part of a transaction in which the right of possession and use of the
User Product is transferred to the recipient in perpetuity or for a
fixed term (regardless of how the transaction is characterized), the
Corresponding Source conveyed under this section must be accompanied
by the Installation Information.  But this requirement does not apply
if neither you nor any third party retains the ability to install
modified object code on the User Product (for example, the work has
been installed in ROM).

  The requirement to provide Installation Information does not include a
requirement to continue to provide support service, warranty, or updates
for a work that has been modified or installed by the recipient, or for
the User Product in which it has been modified or installed.  Access to a
network may be denied when the modification itself materially and
adversely affects the operation of the network or violates the rules and
protocols for communication across the network.

  Corresponding Source conveyed, and Installation Information provided,
in accord with this section must be in a format that is publicly
documented (and with an implementation available to the public in
source code form), and must require no special password or key for
unpacking, reading or copying.

  7. Additional Terms.

  "Additional permissions" are terms that supplement the terms of this
License by making exceptions from one or more of its conditions.
Additional permissions that are applicable to the entire Program shall
be treated as though they were included in this License, to the extent
that they are valid under applicable law.  If additional permissions
apply only to part of the Program, that part may be used separately
under those permissions, but the entire Program remains governed by
this License without regard to the additional permissions.

  When you convey a copy of a covered work, you may at your option
remove any additional permissions from that copy, or from any part of
it.  (Additional permissions may be written to require their own
removal in certain cases when you modify the work.)  You may place
additional permissions on material, added by you to a covered work,
for which you have or can give appropriate copyright permission.

  Notwithstanding any other provision of this License, for material you
add to a covered work, you may (if authorized by the copyright holders of
that material) supplement the terms of this License with terms:

    a) Disclaiming warranty or limiting liability differently from the
    terms of sections 15 and 16 of this License; or

    b) Requiring preservation of specified reasonable legal notices or
    author attributions in that material or in the Appropriate Legal
    Notices displayed by works containing it; or

    c) Prohibiting misrepresentation of the origin of that material, or
    requiring that modified versions of such material be marked in
    reasonable ways as different from the original version; or

    d) Limiting the use for publicity purposes of names of licensors or
    authors of the material; or

    e) Declining to grant rights under trademark law for use of some
    trade names, trademarks, or service marks; or

    f) Requiring indemnification of licensors and authors of that
    material by anyone who conveys the material (or modified versions of
    it) with contractual assumptions of liability to the recipient, for
    any liability that these contractual assumptions directly impose on
    those licensors and authors.

  All other non-permissive additional terms are considered "further
restrictions" within the meaning of section 10.  If the Program as you
received it, or any part of it, contains a notice stating that it is
governed by this License along with a term that is a further
restriction, you may remove that term.  If a license document contains
a further restriction but permits relicensing or conveying under this
License, you may add to a covered work material governed by the terms
of that license document, provided that the further restriction does
not survive such relicensing or conveying.

  If you add terms to a covered work in accord with this section, you
must place, in the relevant source files, a statement of the
additional terms that apply to those files, or a notice indicating
where to find the applicable terms.

  Additional terms, permissive or non-permissive, may be stated in the
form of a separately written license, or stated as exceptions;
the above requirements apply either way.

  8. Termination.

  You may not propagate or modify a covered work except as expressly
provided under this License.  Any attempt otherwise to propagate or
modify it is void, and will automatically terminate your rights under
this License (including any patent licenses granted under the third
paragraph of section 11).

  However, if you cease all violation of this License, then your
license from a particular copyright holder is reinstated (a)
provisionally, unless and until the copyright holder explicitly and
finally terminates your license, and (b) permanently, if the copyright
holder fails to notify you of the violation by some reasonable means
prior to 60 days after the cessation.

  Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from that
copyright holder, and you cure the violation prior to 30 days after
your receipt of the notice.

  Termination of your rights under this section does not terminate the
licenses of parties who have received copies or rights from you under
this License.  If your rights have been terminated and not permanently
reinstated, you do not qualify to receive new licenses for the same
material under section 10.

  9. Acceptance Not Required for Having Copies.

  You are not required to accept this License in order to receive or
run a copy of the Program.  Ancillary propagation of a covered work
occurring solely as a consequence of using peer-to-peer transmission
to receive a copy likewise does not require acceptance.  However,
nothing other than this License grants you permission to propagate or
modify any covered work.  These actions infringe copyright if you do
not accept this License.  Therefore, by modifying or propagating a
covered work, you indicate your acceptance of this License to do so.

  10. Automatic Licensing of Downstream Recipients.

  Each time you convey a covered work, the recipient automatically
receives a license from the original licensors, to run, modify and
propagate that work, subject to this License.  You are not responsible
for enforcing compliance by third parties with this License.

  An "entity transaction" is a transaction transferring control of an
organization, or substantially all assets of one, or subdividing an
organization, or merging organizations.  If propagation of a covered
work results from an entity transaction, each party to that
transaction who receives a copy of the work also receives whatever
licenses to the work the party's predecessor in interest had or could
give under the previous paragraph, plus a right to possession of the
Corresponding Source of the work from the predecessor in interest, if
the predecessor has it or can get it with reasonable efforts.

  You may not impose any further restrictions on the exercise of the
rights granted or affirmed under this License.  For example, you may
not impose a license fee, royalty, or other charge for exercise of
rights granted under this License, and you may not initiate litigation
(including a cross-claim or counterclaim in a lawsuit) alleging that
any patent claim is infringed by making, using, selling, offering for
sale, or importing the Program or any portion of it.

  11. Patents.

  A "contributor" is a copyright holder who authorizes use under this
License of the Program or a work on which the Program is based.  The
work thus licensed is called the contributor's "contributor version".

  A contributor's "essential patent claims" are all patent claims
owned or controlled by the contributor, whether already acquired or
hereafter acquired, that would be infringed by some manner, permitted
by this License, of making, using, or selling its contributor version,
but do not include claims that would be infringed only as a
consequence of further modification of the contributor version.  For
purposes of this definition, "control" includes the right to grant
patent sublicenses in a manner consistent with the requirements of
this License.

  Each contributor grants you a non-exclusive, worldwide, royalty-free
patent license under the contributor's essential patent claims, to
make, use, sell, offer for sale, import and otherwise run, modify and
propagate the contents of its contributor version.

  In the following three paragraphs, a "patent license" is any express
agreement or commitment, however denominated, not to enforce a patent
(such as an express permission to practice a patent or covenant not to
sue for patent infringement).  To "grant" such a patent license to a
party means to make such an agreement or commitment not to enforce a
patent against the party.

  If you convey a covered work, knowingly relying on a patent license,
and the Corresponding Source of the work is not available for anyone
to copy, free of charge and under the terms of this License, through a
publicly available network server or other readily accessible means,
then you must either (1) cause the Corresponding Source to be so
available, or (2) arrange to deprive yourself of the benefit of the
patent license for this particular work, or (3) arrange, in a manner
consistent with the requirements of this License, to extend the patent
license to downstream recipients.  "Knowingly relying" means you have
actual knowledge that, but for the patent license, your conveying the
covered work in a country, or your recipient's use of the covered work
in a country, would infringe one or more identifiable patents in that
country that you have reason to believe are valid.

  If, pursuant to or in connection with a single transaction or
arrangement, you convey, or propagate by procuring conveyance of, a
covered work, and grant a patent license to some of the parties
receiving the covered work authorizing them to use, propagate, modify
or convey a specific copy of the covered work, then the patent license
you grant is automatically extended to all recipients of the covered
work and works based on it.

  A patent license is "discriminatory" if it does not include within
the scope of its coverage, prohibits the exercise of, or is
conditioned on the non-exercise of one or more of the rights that are
specifically granted under this License.  You may not convey a covered
work if you are a party to an arrangement with a third party that is
in the business of distributing software, under which you make payment
to the third party based on the extent of your activity of conveying
the work, and under which the third party grants, to any of the
parties who would receive the covered work from you, a discriminatory
patent license (a) in connection with copies of the covered work
conveyed by you (or copies made from those copies), or (b) primarily
for and in connection with specific products or compilations that
contain the covered work, unless you entered into that arrangement,
or that patent license was granted, prior to 28 March 2007.

  Nothing in this License shall be construed as excluding or limiting
any implied license or other defenses to infringement that may
otherwise be available to you under applicable patent law.

  12. No Surrender of Others' Freedom.

  If conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License.  If you cannot convey a
covered work so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you may
not convey it at all.  For example, if you agree to terms that obligate you
to collect a royalty for further conveying from those to whom you convey
the Program, the only way you could satisfy both those terms and this
License would be to refrain entirely from conveying the Program.

  13. Use with the GNU Affero General Public License.

  Notwithstanding any other provision of this License, you have
permission to link or combine any covered work with a work licensed
under version 3 of the GNU Affero General Public License into a single
combined work, and to convey the resulting work.  The terms of this
License will continue to apply to the part which is the covered work,
but the special requirements of the GNU Affero General Public License,
section 13, concerning interaction through a network will apply to the
combination as such.

  14. Revised Versions of this License.

  The Free Software Foundation may publish revised and/or new versions of
the GNU General Public License from time to time.  Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.

  Each version is given a distinguishing version number.  If the
Program specifies that a certain numbered version of the GNU General
Public License "or any later version" applies to it, you have the
option of following the terms and conditions either of that numbered
version or of any later version published by the Free Software
Foundation.  If the Program does not specify a version number of the
GNU General Public License, you may choose any version ever published
by the Free Software Foundation.

  If the Program specifies that a proxy can decide which future
versions of the GNU General Public License can be used, that proxy's
public statement of acceptance of a version permanently authorizes you
to choose that version for the Program.

  Later license versions may give you additional or different
permissions.  However, no additional obligations are imposed on any
author or copyright holder as a result of your choosing to follow a
later version.

  15. Disclaimer of Warranty.

  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

  16. Limitation of Liability.

  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.

  17. Interpretation of Sections 15 and 16.

  If the disclaimer of warranty and limitation of liability provided
above cannot be given local legal effect according to their terms,
reviewing courts shall apply local law that most closely approximates
an absolute waiver of all civil liability in connection with the
Program, unless a warranty or assumption of liability accompanies a
copy of the Program in return for a fee.

                     END OF TERMS AND CONDITIONS

            How to Apply These Terms to Your New Programs

  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.

  To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
state the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.

Also add information on how to contact you by electronic and paper mail.

  If the program does terminal interaction, make it output a short
notice like this when it starts in an interactive mode:

    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.

The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License.  Of course, your program's commands
might be different; for a GUI interface, you would use an "about box".

  You should also get your employer (if you work as a programmer) or school,
if any, to sign a "copyright disclaimer" for the program, if necessary.
For more information on this, and how to apply and follow the GNU GPL, see
<https://www.gnu.org/licenses/>.

  The GNU General Public License does not permit incorporating your program
into proprietary programs.  If your program is a subroutine library, you
may consider it more useful to permit linking proprietary applications with
the library.  If this is what you want to do, use the GNU Lesser General
Public License instead of this License.  But first, please read
<https://www.gnu.org/licenses/why-not-lgpl.html>.

Indices and tables

• Index

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