Software license issue

[estshorter]

I think SHT3x.h and SHT3x.cpp are derived from https://github.com/Risele/SHT3x which is licensed under the GPL-3.0. If I understand the GPL correctly, this repository must be licensed under the GPL-3.0 too.

Also, Button.h and Button.cpp are licensed under CC BY-SA 3.0, which means that this repository must be licensed under the CC BY-SA 3.0.

CommUtil.h and M5Timer.h are licensed under LGPL-2.1 (strictly speaking, LGPL-2.1-only and LGPL-2.1-or-later). They cannot be distributed under MIT license.

Note: I love M5Stack products, but everyone must obey the software license...

[lienbacher]

I also really like M5Stack Hardware, but M5Stack Software is quite underwhelming so far tbh.
Please please up your software game m5stack!

[estshorter]

@Gitshaoxiang ping

[ikedam]

I ran grep -ri license . and found this library contains following licensed codes:

• FreeType license: https://gitlab.freedesktop.org/freetype/freetype/-/blob/master/docs/FTL.TXT
  • src/base/*
  • src/freetype/*
  • src/ft2build.h
  • src/sfnt/*
  • src/smooth/*
  • src/truetype/*
• MIT / BSD / FreeBSD license: https://github.com/Bodmer/TFT_eSPI/blob/master/license.txt
  • TFT_eSPI, Sprite.
  • This repository doesn't look contain the license notice for those files. Written as "see license in root directory" in source codes, but the license file in the root directory differs the original one.
  • Files in src/Fonts/* look also come from the same source.
• BSD license: https://github.com/m5stack/M5EPD/blob/0.1.1/src/Fonts/GFXFF/license.txt
  • Those files look parts of TFT_eSPI.
• 3-clause BSD license: https://github.com/m5stack/M5EPD/blob/0.1.1/src/Fonts/GFXFF/TomThumb.h#L2
  • Tom Thumb 3x5 font.
• MIT license: https://github.com/espressif/WROVER_KIT_LCD/blob/master/README.md
  • M5EPD_Canvas
  • Not so sure, but supposed so.
  • The copyright notice in that file looks broken. (No copyright holder)
• MIT license: https://github.com/kikuchan/pngle/blob/master/LICENSE
  • pngle
• MIT license: https://github.com/ricmoo/QRCode/blob/master/LICENSE.txt
  • qrcode

As far as I understand above licenses (but not so sure):

• Missing copyright and license notices must be added to the repository.
• Software using this library must have copyright notices for above licenses if they are distributed only in binary form.
• Above licenses doesn't prevent this repository licensed under the MIT license, as copyright notices in sources are reachable from anyone.
  • Though, it would be better to have LICENSE clarify the licenses this library rely on.
  • Of course, licenses described in the description of this issue prevents this repository licensed under the MIT license.

[Gitshaoxiang]

thank you feedback. we are working to solve this problem now.