Add licences (CERN-OHL-S-2.0 for hardware, MIT for firmware/docs) and licence notes

LICENSE

@@ -0,0 +1,285 @@
+CERN Open Hardware Licence Version 2 - Strongly Reciprocal
+
+
+Preamble
+
+CERN has developed this licence to promote collaboration among
+hardware designers and to provide a legal tool which supports the
+freedom to use, study, modify, share and distribute hardware designs
+and products based on those designs. Version 2 of the CERN Open
+Hardware Licence comes in three variants: CERN-OHL-P (permissive); and
+two reciprocal licences: CERN-OHL-W (weakly reciprocal) and this
+licence, CERN-OHL-S (strongly reciprocal).
+
+The CERN-OHL-S is copyright CERN 2020. Anyone is welcome to use it, in
+unmodified form only.
+
+Use of this Licence does not imply any endorsement by CERN of any
+Licensor or their designs nor does it imply any involvement by CERN in
+their development.
+
+
+1 Definitions
+
+  1.1 'Licence' means this CERN-OHL-S.
+
+  1.2 'Compatible Licence' means
+
+       a) any earlier version of the CERN Open Hardware licence, or
+
+       b) any version of the CERN-OHL-S, or
+
+       c) any licence which permits You to treat the Source to which
+          it applies as licensed under CERN-OHL-S provided that on
+          Conveyance of any such Source, or any associated Product You
+          treat the Source in question as being licensed under CERN-OHL-S.
+
+  1.3 'Source' means information such as design materials or digital
+      code which can be applied to Make or test a Product or to
+      prepare a Product for use, Conveyance or sale, regardless of its
+      medium or how it is expressed. It may include Notices.
+
+  1.4 'Covered Source' means Source that is explicitly made available
+      under this Licence.
+
+  1.5 'Product' means any device, component, work or physical object,
+      whether in finished or intermediate form, arising from the use,
+      application or processing of Covered Source.
+
+  1.6 'Make' means to create or configure something, whether by
+      manufacture, assembly, compiling, loading or applying Covered
+      Source or another Product or otherwise.
+
+  1.7 'Available Component' means any part, sub-assembly, library or
+      code which:
+
+       a) is licensed to You as Complete Source under a Compatible
+          Licence; or
+
+       b) is available, at the time a Product or the Source containing
+          it is first Conveyed, to You and any other prospective
+          licensees
+
+            i) as a physical part with sufficient rights and
+               information (including any configuration and programming
+               files and information about its characteristics and
+               interfaces) to enable it either to be Made itself, or to
+               be sourced and used to Make the Product; or
+           ii) as part of the normal distribution of a tool used to
+               design or Make the Product.
+
+  1.8 'Complete Source' means the set of all Source necessary to Make
+      a Product, in the preferred form for making modifications,
+      including necessary installation and interfacing information both
+      for the Product, and for any included Available Components. If
+      the format is proprietary, it must also be made available in a
+      format (if the proprietary tool can create it) which is viewable
+      with a tool available to potential licensees and licensed under a
+      licence approved by the Free Software Foundation or the Open
+      Source Initiative. Complete Source need not include the Source of
+      any Available Component, provided that You include in the
+      Complete Source sufficient information to enable a recipient to
+      Make or source and use the Available Component to Make the
+      Product.
+
+  1.9 'Source Location' means a location where a Licensor has placed
+      Covered Source, and which that Licensor reasonably believes will
+      remain easily accessible for at least three years for anyone to
+      obtain a digital copy.
+
+ 1.10 'Notice' means copyright, acknowledgement and trademark notices,
+      Source Location references, modification notices (subsection
+      3.3(b)) and all notices that refer to this Licence and to the
+      disclaimer of warranties that are included in the Covered Source.
+
+ 1.11 'Licensee' or 'You' means any person exercising rights under
+      this Licence.
+
+ 1.12 'Licensor' means a natural or legal person who creates or
+      modifies Covered Source. A person may be a Licensee and a
+      Licensor at the same time.
+
+ 1.13 'Convey' means to communicate to the public or distribute.
+
+
+2 Applicability
+
+  2.1 This Licence governs the use, copying, modification, Conveying
+      of Covered Source and Products, and the Making of Products. By
+      exercising any right granted under this Licence, You irrevocably
+      accept these terms and conditions.
+
+  2.2 This Licence is granted by the Licensor directly to You, and
+      shall apply worldwide and without limitation in time.
+
+  2.3 You shall not attempt to restrict by contract or otherwise the
+      rights granted under this Licence to other Licensees.
+
+  2.4 This Licence is not intended to restrict fair use, fair dealing,
+      or any other similar right.
+
+
+3 Copying, modifying and Conveying Covered Source
+
+  3.1 You may copy and Convey verbatim copies of Covered Source, in
+      any medium, provided You retain all Notices.
+
+  3.2 You may modify Covered Source, other than Notices, provided that
+      You irrevocably undertake to make that modified Covered Source
+      available from a Source Location should You Convey a Product in
+      circumstances where the recipient does not otherwise receive a
+      copy of the modified Covered Source. In each case subsection 3.3
+      shall apply.
+
+      You may only delete Notices if they are no longer applicable to
+      the corresponding Covered Source as modified by You and You may
+      add additional Notices applicable to Your modifications.
+      Including Covered Source in a larger work is modifying the
+      Covered Source, and the larger work becomes modified Covered
+      Source.
+
+  3.3 You may Convey modified Covered Source (with the effect that You
+      shall also become a Licensor) provided that You:
+
+       a) retain Notices as required in subsection 3.2;
+
+       b) add a Notice to the modified Covered Source stating that You
+          have modified it, with the date and brief description of how
+          You have modified it;
+
+       c) add a Source Location Notice for the modified Covered Source
+          if You Convey in circumstances where the recipient does not
+          otherwise receive a copy of the modified Covered Source; and
+
+       d) license the modified Covered Source under the terms and
+          conditions of this Licence (or, as set out in subsection 8.3,
+          a later version, if permitted by the licence of the original
+          Covered Source). Such modified Covered Source must be
+          licensed as a whole, but excluding Available Components
+          contained in it, which remain licensed under their own
+          applicable licences.
+
+
+4 Making and Conveying Products
+
+You may Make Products, and/or Convey them, provided that You either
+provide each recipient with a copy of the Complete Source or ensure
+that each recipient is notified of the Source Location of the Complete
+Source. That Complete Source is Covered Source, and You must
+accordingly satisfy Your obligations set out in subsection 3.3. If
+specified in a Notice, the Product must visibly and securely display
+the Source Location on it or its packaging or documentation in the
+manner specified in that Notice.
+
+
+5 Research and Development
+
+You may Convey Covered Source, modified Covered Source or Products to
+a legal entity carrying out development, testing or quality assurance
+work on Your behalf provided that the work is performed on terms which
+prevent the entity from both using the Source or Products for its own
+internal purposes and Conveying the Source or Products or any
+modifications to them to any person other than You. Any modifications
+made by the entity shall be deemed to be made by You pursuant to
+subsection 3.2.
+
+
+6 DISCLAIMER AND LIABILITY
+
+  6.1 DISCLAIMER OF WARRANTY -- The Covered Source and any Products
+      are provided 'as is' and any express or implied warranties,
+      including, but not limited to, implied warranties of
+      merchantability, of satisfactory quality, non-infringement of
+      third party rights, and fitness for a particular purpose or use
+      are disclaimed in respect of any Source or Product to the maximum
+      extent permitted by law. The Licensor makes no representation
+      that any Source or Product does not or will not infringe any
+      patent, copyright, trade secret or other proprietary right. The
+      entire risk as to the use, quality, and performance of any
+      Source or Product shall be with You and not the Licensor. This
+      disclaimer of warranty is an essential part of this Licence and a
+      condition for the grant of any rights granted under this Licence.
+
+  6.2 EXCLUSION AND LIMITATION OF LIABILITY -- The Licensor shall, to
+      the maximum extent permitted by law, have no liability for
+      direct, indirect, special, incidental, consequential, exemplary,
+      punitive or other damages of any character including, without
+      limitation, procurement of substitute goods or services, loss of
+      use, data or profits, or business interruption, however caused
+      and on any theory of contract, warranty, tort (including
+      negligence), product liability or otherwise, arising in any way
+      in relation to the Covered Source, modified Covered Source
+      and/or the Making or Conveyance of a Product, even if advised of
+      the possibility of such damages, and You shall hold the
+      Licensor(s) free and harmless from any liability, costs, damages,
+      fees and expenses, including claims by third parties, in relation
+      to such use.
+
+
+7 Patents
+
+  7.1 Subject to the terms and conditions of this Licence, each
+      Licensor hereby grants to You a perpetual, worldwide,
+      non-exclusive, no-charge, royalty-free, irrevocable (except as
+      stated in subsections 7.2 and 8.4) patent license to Make, have
+      Made, use, offer to sell, sell, import, and otherwise transfer
+      the Covered Source and Products, where such licence applies only
+      to those patent claims licensable by such Licensor that are
+      necessarily infringed by exercising rights under the Covered
+      Source as Conveyed by that Licensor.
+
+  7.2 If You institute patent litigation against any entity (including
+      a cross-claim or counterclaim in a lawsuit) alleging that the
+      Covered Source or a Product constitutes direct or contributory
+      patent infringement, or You seek any declaration that a patent
+      licensed to You under this Licence is invalid or unenforceable
+      then any rights granted to You under this Licence shall terminate
+      as of the date such process is initiated.
+
+
+8 General
+
+  8.1 If any provisions of this Licence are or subsequently become
+      invalid or unenforceable for any reason, the remaining
+      provisions shall remain effective.
+
+  8.2 You shall not use any of the name (including acronyms and
+      abbreviations), image, or logo by which the Licensor or CERN is
+      known, except where needed to comply with section 3, or where the
+      use is otherwise allowed by law. Any such permitted use shall be
+      factual and shall not be made so as to suggest any kind of
+      endorsement or implication of involvement by the Licensor or its
+      personnel.
+
+  8.3 CERN may publish updated versions and variants of this Licence
+      which it considers to be in the spirit of this version, but may
+      differ in detail to address new problems or concerns. New
+      versions will be published with a unique version number and a
+      variant identifier specifying the variant. If the Licensor has
+      specified that a given variant applies to the Covered Source
+      without specifying a version, You may treat that Covered Source
+      as being released under any version of the CERN-OHL with that
+      variant. If no variant is specified, the Covered Source shall be
+      treated as being released under CERN-OHL-S. The Licensor may also
+      specify that the Covered Source is subject to a specific version
+      of the CERN-OHL or any later version in which case You may apply
+      this or any later version of CERN-OHL with the same variant
+      identifier published by CERN.
+
+  8.4 This Licence shall terminate with immediate effect if You fail
+      to comply with any of its terms and conditions.
+
+  8.5 However, if You cease all breaches of this Licence, then Your
+      Licence from any Licensor is reinstated unless such Licensor has
+      terminated this Licence by giving You, while You remain in
+      breach, a notice specifying the breach and requiring You to cure
+      it within 30 days, and You have failed to come into compliance in
+      all material respects by the end of the 30 day period. Should You
+      repeat the breach after receipt of a cure notice and subsequent
+      reinstatement, this Licence will terminate immediately and
+      permanently. Section 6 shall continue to apply after any
+      termination.
+
+  8.6 This Licence shall not be enforceable except by a Licensor
+      acting as such, and third party beneficiary rights are
+      specifically excluded.

LICENSE.MIT

@@ -0,0 +1,18 @@
+MIT License
+
+Copyright (c) 2026 Hannes Gehrmann
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the
+following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial
+portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO
+EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
+THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

@@ -142,7 +142,9 @@ S8 UART: 9600 baud, 8N1. BME280 I²C: standard address `0x76` (or `0x77` dependi
 ├── bom/                         bill of materials (CSV)
 ├── docs/                        schematic PDF, layer plots, 3D render
 ├── firmware/                    ESPHome configuration
-└── photos/                      photographs of the assembled board
+├── photos/                      photographs of the assembled board
+├── LICENSE                      CERN-OHL-S-2.0 (hardware)
+└── LICENSE.MIT                  MIT (firmware config, BOM, docs)
 ```
 
 ## Rebuilding the board
@@ -156,6 +158,20 @@ S8 UART: 9600 baud, 8N1. BME280 I²C: standard address `0x76` (or `0x77` dependi
 
 ## License
 
-Not chosen yet. Recommended for a published open-hardware module:
+Dual licensed, SPDX identifiers:
-**CERN-OHL-S-2.0** for the hardware (schematic, layout, footprints) and **MIT** for the firmware
+
-configuration and scripts. A `LICENSE` file must be added before publishing.
+| Scope | Licence | File |
+|---|---|---|
+| Hardware: schematic, layout, symbols, footprints, fabrication data | **CERN-OHL-S-2.0** (CERN Open Hardware Licence v2, strongly reciprocal) | [`LICENSE`](LICENSE) |
+| Firmware configuration, BOM, scripts, documentation | **MIT** | [`LICENSE.MIT`](LICENSE.MIT) |
+
+SPDX notices to keep in derived files:
+
+```
+SPDX-License-Identifier: CERN-OHL-S-2.0
+SPDX-FileCopyrightText: 2026 Hannes Gehrmann
+```
+
+Making a board from these files and distributing it is explicitly allowed; if you modify the design
+and convey it, CERN-OHL-S requires you to publish the modified design under the same licence and to
+mark what you changed (sections 3.2 and 3.3).