Your warranty is now probably void. I am not responsible for any bricked devices, do this at your own risk!
Over the last few weeks i really investigated into looking where the notification icon data is stored in the firmware files, because i really wanted to be able to use custom icons, as 50% wont be used anyway because i dont know what those apps are supposted to be. After i managed to find out about the location of most icons i started to make a small windows program which would help to edit those icons easily, and its at the point where its working and can do all the basic stuff it should do (loading/saving the firmware files, reading the icon data from the firmware file, small editor).
Here is a link to the gitlab repo where you can find the program (MiFirmwareEditor.exe) and the Visual Studio sourcecode.
https:// gitlab. com/berryelectronics/mi-band-2-firmware-editor/
(remove the spaces after "https://" and "gitlab.")
At the moment it only works with the version 18.104.22.168 of the firmware, as that is the one i used to find all the location of the data, though i might look into supporting newer firmware files.
But you have to get that firmware file for yourself, as i doubt that i am allowed to host that too. luckily there is a good instruction in the gadgetbridge wiki onto how to get those files.
Better make sure the firmware version you have is infact version 22.214.171.124 by flashing the unedited onto your Mi Band 2 and look what your app says is your current firmware version.
Sometimes it doesnt really refresh the drawing grid, so you might press the "redraw eidtor" button in this case.
Because it is in a very early stage, i would be pleased to get feedback and error reports if you find any
Thanks to SirStefan for the documentation of the font data for the small text used for the date. Post