this kind of optic fiber is probably only plastic so for a full DIY , you can use also fishing wire with a big power led or an old chistmass tree optic fiber lighted.....
I have already published all the documentation, on my website, GitHub and openhardware.io
For now I leave the node as finished.
SmartHome: Wireless LED RGBW Controller – 00:55— giltesa
I apologize for the questions and how simple they may be, as Im new to this community but very intrigued with the creativity and endless possibilities.