Thanks . I’m doing this for fun - not for profit, so I think I’ll share it - why not.
But first I have to finish it and clean up my code because it’s a terrible mess - now I’m a little ashamed of how it looks inside 
I think I will create some tutorial or documentation to make it more useful and understandable for everyone.
Thanks.
I would like to make some additional modification / improvement: In the original enclosure you can control the Led lighting and fan speed with the M-code M1010 :
M1010 Sx Px
* S0: disable door event
* S1: enable door event
* S3: set light power, P 0-100%, eg.M1010 S3 P100 -> light 100%
* S4: set fan power, P 0-100%, eg.M1010 S4 P100 -> fan 100%
Parameter P is linear and means power in percent:
- P0 - 0% of power - means OFF
- P50 - 50% power
- P100 - 100% power - means ON
But de facto it can take the values 0-255 (that’s one byte). So the values 101-255 are unused and treated always as 100%.
I would like to add an additional RGB LED strip to my DIY enclosure, connect to this controller and then use the values from P101 … to P255 to switch different colors in this additional lighting - for example P101 - green, P102 blue … etc etc. also many RGB color mixes.
Then such a color change command, e.g. M1010 S3 P150, can be inserted into a Gcode executed by the printer and various interesting effects of color lighting can be generated automatically.
I think it would be cool and effective e.g. for recording a timelapse movie, etc.