A physical switch that informs everyone whether the TU-DO Makerspace is currently open or closed.
- Communication Channels
- Overview
- Hardware - Building the Activity Indicator
- Software - Setting up the Activity Indicator
- Emulation
- License
The following communication channels are currently offered to obtain infromation about the Makerspace's activity status:
The Activity Indicator is a device designed to inform the public about the current open/closed status of the Makerspace, particularly when regular opening times cannot be maintained. It is designed to be powered by a Raspberry Pi Zero W, however, other Linux-capable RPi's and their clones such as Banana Pi's can also be used to run it. It features two status LEDs: a red LED indicating power and a multicolor LED indicating internet connectivity (green for available, red for unavailable). The indicator is controlled by a systemd service that monitors and manages the activity switch and continuously checks for internet connectivity.
The software for the Activity Indicator is not limited to use in the TU-DO Makerspace and can be configured to execute any desired commands upon switch events. The included script for sending Telegram messages can be configured to send notifications to multiple chats/chat groups, and allows for customization of the messages for opening and closing events.
A comprehensive guide to building and setting up your own Activity Indicator, including detailed information on the hardware and software, can be found in the forthcoming sections.
The following components are required to build the Activity Indicator:
- A Switch
- Any Linux capable Raspberry Pi board or a compatible clone (We use the Pi Zero W)
- A red LED for the power status
- A multi-color common red and green LED for the internet connection indicator (Alternatively two seperate red and green LEDs can be used)
- 1x 1k Ohm resistor for the power LED
- 1x 100 Ohm resistor for the connection indicator LED
- Connect the anode (+) of the Power LED, with a 1k resistor in series, to one of the Raspberry Pi's 5V pins, and connect the cathode (-) of the LED to one of the ground pins.
- Connect the pins of the connection indicator LED to any of the Raspberry Pi's GPIO pins. Ensure that the common ground pin has a 100 Ohm resistor connected in series.
- For the Switch, connect one end to a GPIO pin on the Raspberry Pi, and the other end to one of the RPi's ground pins.
A possible configuration for the Raspberry Pi Zero W is shown below in the accompanying diagram:
As already mentioned, the Activity Indicator is not limited to the Pi Zero W only. Any other Linux capable Raspberry Pi boards (or their compatbile clones) can be used as well. The specific GPIO pins used for the switch and the connection indicator LED can be configured in the software. Once the software for the activity indicator is set up and functioning properly, it is recommended to place the hardware in a solid enclosure.
The repo provides a 3D-Printable enclosure for a Pi Zero based Activity Indicator in the enclosure directory. The enclosure consists of a base, a top and a couple of "text boxes". These are provided as STL and 3MF. The Labels.pdf file contains the labels meant to be glued onto the text boxes.
A Fusion 360 f3z file has also been provided in the enclosure directory if you wish to modify the enclosure.
If your Raspberry Pi is not already set up with a OS, make sure to install one first. Since the Activity Indicator has been written with RPi OS Bullseye in mind, this guide will assume that RPi OS Bullseye is installed. If you are using a different OS, you may need to take extra steps on your own to get things up and running.
Once the OS has been installed, and an active internet connection has been established, ensure git has been installed:
$ sudo apt install git
Proceed to clone the repo into your Pi's home directory (Or anywhere else), and enter the project directory:
$ cd ~ && git clone https://github.com/TU-DO-Makerspace/Activity-Indicator && cd Activity-Indicator
To install the necessary software dependencies, run the setup.sh script with the dependencies option:
$ sudo ./setup.sh dependencies
This will install all required apt packages and python modules.
Note: This section can be skipped if your only goal is to set up the software.
This section provides a brief overview of the software behind the activity-indicator.
The activity indicator software is primarily driven by the activity-indicator.py script, which monitors and handles changes in the activity switch. It is launched as a systemd service and runs continuously in the background.
When a change in the activity switch is detected, the script executes all subservices defined in the activity-indicator.ini configuration file, which are assigned to the committed action (open or closed). Each subservice defined in the configuration file can contain a command to be executed upon setting the switch to its opening position (OpenExec) or closing position (ClosedExec). Setting up the configuration file is explained in the "Configuring the software" section.
The script also checks for internet connectivity and sets the color of the connection indicator LED accordingly. If no internet connection is available, the program is halted and resumes execution when a connection is re-established. If the switch position is changed while no internet connection is available, the change will be registered when the connection is re-established.
The script also handles unexpected errors by printing an error message and blinking the connection LED green and red 3 times. The systemd service unit for the script, activity-indicator.service, is configured to automatically restart the script after it exits, so the script does not need to be manually started again after a crash or unexpected exit.
The scripts and configuration files for running a Telegram bot can be found in the software/telegram folder.
The telegram-activity-indicator.py script is responsible for sending opening and closing messages to one or more chats. Chats and their corresponding opening and closing messages can be configured in the telegram.ini configuration file. Setting up the configuration file is explained in the "Configuring the software" section.
The script takes a path to a configuration file (-c, default is set to telegram.ini) and an activity status (open or closed) as arguments. It also allows users to set the log level using the -l flag, which is set to INFO if left out. The full script usage can be printed by providing it the -h option.
The telegram-activity-indicator.py script can be executed manually, but it was designed to be executed by the activity-indicator service. To make use of the Telegram bot, it must be specified in the activity-indicator.ini configuration file. The default activity-indicator.ini provided in this repo already includes this configuration.
A TYPO3 extension has been developed to display the current activity status on the website of our Makerspace. The extension can be found here and can be controlled through a REST API.
The scripts and configuration files required to connect the Activity Indicator to the TYPO3 extension can be found in the software/typo3 folder.
The typo3-activity-indicator.py script is responsible for sending the current activity status to the TYPO3 extension via a POST REST API request. The script takes a path to a configuration file (-c, default is set to typo3.ini), which holds HTTP Basic Auth credentials and the API URL, and takes an activity status (open or closed) as an argument.
The full script usage can be printed by providing it the -h option.
The typo3-activity-indicator.py script can be executed manually, but it was designed to be executed by the activity-indicator service. To connect the Activity Indicator to a TYPO3 website, it must be specified in the activity-indicator.ini configuration file. The default activity-indicator.ini provided in this repo already includes this configuration, but it is commented out by default as it is likely not to be used by other users than our makerspace. (more on that in the "Configuring the software" section).
The first step is to configure the main activity-indicator configuration file, which can be found at software/activity-indicator.ini. By default the configuration file will contain the following content:
; Change this to your hardware configuration
[GPIO]
Switch = 16
ConLEDGreen = 20
ConLEDRed = 21
[telegram]
OpenExec = /usr/bin/python3 /usr/share/pyshared/activity-indicator/telegram/telegram-activity-indicator.py -c /var/lib/activity-indicator/telegram.ini open
ClosedExec = /usr/bin/python3 /usr/share/pyshared/activity-indicator/telegram/telegram-activity-indicator.py -c /var/lib/activity-indicator/telegram.ini closed
; [typo3]
; OpenExec = /usr/bin/python3 /usr/share/pyshared/activity-indicator/typo3/typo3-activity-indicator.py -c /var/lib/activity-indicator/typo3.ini open
; ClosedExec = /usr/bin/python3 /usr/share/pyshared/activity-indicator/typo3/typo3-activity-indicator.py -c /var/lib/activity-indicator/typo3.ini closed
; [your_subservice_name]
; OpenExec = COMMAND TO RUN WHEN ACTIVITY HAS CHANGED TO OPEN
; ClosedExec = COMMAND TO RUN WHEN ACTIVITY HAS CHANGED TO CLOSED
Make sure to assign the correct GPIOs to your own configuration if they do not already match the ones above.
The [telegram] section provides the commands to execute the telegram-bot subservice. If you do not wish to use a telegram bot for the activity indicator, comment out or remove this entry.
The [typo3] section provides the commands to update the activity status on a TYPO3 website with the Activity Indicator extension installed. Since this is more specific to our Makerspace's website than the Telegram bot is, it is commented out by default. Should you be running a TYPO3 website too, you can gladly install the Activity-Indicator extension and uncomment this section.
Adding additional subservices is elaborated further in the "Adding custom subservices" section below.
Note: Skip this section if you're not planning to use a telegram bot.
First, create a telegram bot if you have not done so already. To create a new bot, you will have to message the BotFather (See https://core.telegram.org/bots#6-botfather).
Once the bot has been created, open the telegram.ini configuration file, located at software/telegram/telegram.ini, which should contain the following content:
[bot]
Token = INSERT YOUR BOT TOKEN HERE
[chat1] # Can be named anything except 'bot'
ChatID = INSERT YOUR CHAT ID HERE
OpenMessage = INSERT YOUR OPEN MESSAGE HERE
ClosedMessage = INSERT YOUR CLOSED MESSAGE HERE
; [chat2]
; ChatID = INSERT YOUR CHAT ID HERE
; OpenMessage = INSERT YOUR OPEN MESSAGE HERE
; ClosedMessage = INSERT YOUR CLOSED MESSAGE HERE
# Add more if necessary
In the bot section, specify the token of the bot you created. You should have received this token from the BotFather upon creating your bot.
Next up, you will need to specify the target chats that should be notified of the activity change. You can add as many chats as you want and name them anything except 'bot'. Each chat section takes a chat ID (ChatID, see this stack overflow thread to learn how to get the ID of a chat), the message to send when the activity has changed to open(OpenMessage) and the message to send when the activity has changed to closed (ClosedMessage).
An example configuration could look like this:
[bot]
Token = 110201543:AAHdqTcvCH1vGWJxfSeofSAs0K5PALDsaw
[TUDO Activity Indicator]
ChatID = -1001512093131
OpenMessage = TUDO is open!
ClosedMessage = TUDO is closed!
Note: Skip this section if you're not planning to connect the Activity indicator to the TYPO3 Activity Indicator extension.
Before configuring the Activity Indicator software, ensure that your TYPO3 instance has the Activity Indicator extension installed and configured. Should this not be the case, please refer to the documentation of the TYPO3 Activity Indicator extension (Not available yet).
Once the extension is installed and configured, you can connect the Activity Indicator to the extension by editing the typo3.ini configuration file located at software/typo3/typo3.ini. By default the configuration file will contain the following content:
[api]
Username = INSERT YOUR HTTP BASIC AUTH USERNAME HERE
Password = INSERT YOUR HTTP BASIC AUTH PASSWORD HERE
URL = INSRET YOUR WEBSITE URL HERE
The configuration file requires the HTTP Basic Auth username and password to obtain access the extensions rest API, as well as a ULR to the TYPO3 website with the Activity Indicator extension installed.
An example configuration could look like this:
[api]
Username = activityindicator
Password = 123456789
URL = https://tu-do.net
Adding a custom subservice is as simple as adding a new section to the activity-indicator configuration file. The section name should describe the subservice, and the commands to execute should be specified in the OpenExec and ClosedExec entries.
Where to store your subservice program or script is up to you.
As an example, suppose we wish to save the current time every time the activity changes. We can add the following lines to the configuration file:
[time]
OpenExec = echo "$(date)" >> ~/opening_times.txt
ClosedExec = echo "$(date)" >> ~/closing_times.txt
After configuring the software, simply execute the setup script at the top of the project directory, with the install option provided:
$ sudo ./setup.sh install
The activity indicator should now be alive and running! Should it not be working correctly, please check the systemd log for any possible errors using the following command:
$ journalctl -f -u activity-indicator.service
Also ensure to double check wether your GPIO's are really set correctly.
To update the softare after applying changes, simply execute the setup script with the install option again.
To uninstall the software, simply execute the setup script with the uninstall option:
$ sudo ./setup.sh uninstall
When developing new features for the Activity Indicator, it may be comfortable to emulate the Activity Indicator in a virtual Raspberry Pi emulation instead of needing to access physical Raspberry Pi board. Thankfully, qemu, along with berdav's qemu-rpi-gpio tool, can be used to run a a virtual Raspberry Pi with support for GPIO emulation.
Note: qemu-rpi-gpio has been written for debian based distributions. As a result, it is likely this guide will not work on other linux distributions.
To establish an emulation environment for the activity indicator, begin by ensuring the following dependencies are installed first:
For Ubuntu 21.10 and above, the depencies can be installed with the following command:
$ sudo apt install git python3 python3-pexpect p7zip-full qemu-system-arm socatFor Ubuntu versions prior to 21.10, ensure QEMU is installed from a source with version 5.10 or above. For Ubuntu 20.04, this is possible by adding the canonical-server backports PPA to your system:
# For Ubuntu 20.04:
$ sudo add-apt-repository ppa:canonical-server/server-backports && sudo apt update
$ sudo apt install git python3 python3-pexpect p7zip-full qemu-system-arm socatProceed by cloning the qemu-rpi-gpio repository, and entering its directory:
$ git clone https://github.com/berdav/qemu-rpi-gpio.git && cd qemu-rpi-gpio
Run the setup script which will install some required dependencies, fetch the latest RPi OS image, and create a mounting point for the RPi emulator.
$ ./qemu-pi-setup/setup.sh
Once the setup script has completed, run the qemu-rpi-gpio to provide the virtual GPIOs to the emulator:
$ ./qemu-rpi-gpioThe script will enter an interactive shell, where GPIO inputs can be emulated. For now, keep the shell open in the background and open a new terminal. Within the new terminal, start up the RPi emulation using the run script:
$ ./qemu-pi-setup/run.sh
The RPi emulator should now be up and running and you will be greeted with a login shell. At the time of writing, the default username is pi and the default password is raspberry. Once logged in, we will need to expand the disk size of the root partition, as it is currently limited to only 1.6GB.
In the emulator shell, run the fdisk utility and provide /dev/mmcblk0 as the device to be partitioned:
$ sudo fdisk /dev/mmcblk0This will enter an interactive shell. Enter the p command to display a list of partitions and note down the start sector of the root partition (/dev/mmcblk0p2):
Command (m for help): p
Disk /dev/mmcblk0: 2 GiB, 2147483648 bytes, 4194304 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xe72b8fd1
Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 8192 532479 524288 256M c W95 FAT32 (LBA)
/dev/mmcblk0p2 532480 3923967 3391488 1.6G 83 Linux
In this example, the root partition starts at sector 532480, however, this may be different on your system.
The next step is to delete the root partition and create a new one with a larger size. Enter the following commands (credit):
d - to delete a partition
2 - choose partition 2
n - create a new partition
p - make it primary
2 - partition number
xxxxx - the starting sector of the original partition 2
Enter - to accept the last sector of the disk as the end of the partition
y - when it asks if you want to remove the signature
w - to write all changes to disk
The size of the partition should now be increased to 1.7G, only by about 100MB, but enough to download the necessities for the Activity Indicator to work.
Finally, complete the resizing of the root partition by entering the following commands:
$ sudo resize2fs /dev/mmcblk0p2
Begin by updating your repo list and installing git on your emulated RPi system:
$ sudo apt update && sudo apt install gitClone the Activity Indiactor repo into your emulators home directory (Or anywhere else), and enter the project directory:
$ cd ~ && git clone https://github.com/TU-DO-Makerspace/Activity-Indicator && cd Activity-Indicator
To install the necessary software dependencies, run the setup.sh script with the dependencies option:
$ sudo ./setup.sh dependencies
At this point, ensure all configuration files (activity-indicator.ini etc., see Configuring the software) in the repository are configured to your needs. Finally, run the setup script with the install-emu option:
$ sudo ./setup.sh install-emuThe Activity Indicator should now be running. The next step is to simulate GPIO inputs.
To simulate GPIO inputs, open the interactive qemu-rpi-gpio shell which we started earlier. Within the shell, use the following commands to simulate GPIO inputs (credits):
The main commands in the qemu-rpi-gpio application are:
| command | description | example |
|---|---|---|
get $N |
get the value of GPIO $N | get 4 |
set $N $V |
set the value of GPIO $N to $V (1 or 0) | set 4 1 |
You can get the full list of commands using help
For example, in our configuration, the Activity Indicator switch is connected to GPIO 16. To simulate the switch being set to CLOSED, we can use the following command:
set 16 1
Note that it may seem counter intuitive to set the GPIO to 1 to set the switch to CLOSED, but this is because the real GPIO is configured to use a pull-up resistor.
Contrary, to simulate the switch being set to OPEN, we can use the following command:
set 16 0
Should your Activity Indicator not react after setting the GPIO's, try to toggle the GPIO between 0 and 1, as you may have set it to the "previous state" of the switch already.
Should things still not work as expected, inspect the service logs for the activity indicator service, and see if they report any errors:
$ journalctl -f -u activity-indicator.service
This project is licensed under the GPLv3 license.
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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>.