Is it allowed to sell a product which includes libraries that isn't yours?
Must I contact them first or am I allowed to ?
Here are the libraries-
#include <FastLED.h>
#include <RF24.h>
#include <RF24Network.h>
#include <SPI.h>
(deleted)
DutchOrange:
Is it allowed to sell a product which includes libraries that isn't yours?
That depends on the terms of the licence for each library. It could be very tedious tracking them all down. Many of the Open Source licences do permit commercial use provided the Open Source status of the library code is not compromised.
If you are proposing to sell large numbers of a profitable product the correct thing would be to get professional legal advice which would not be cheap. Neither is it guaranteed to be correct, but at least you could demonstrate to your shareholders that you had taken all reasonable precautions.
Assuming you are not envisaging $millions in turnover ...
Is your product essentially a hardware item or is it entirely software?
I suspect the licencing conditions would be more important if what you are selling is software.
If your product is essentially hardware then the easiest way to comply with the licences might be to make your software Open Source
...R
Generally, look for a “license” file associated with the source code.
There are a couple of common licences with “well known” properties:
MIT, BSD, APACHE: commercial, proprietary use is fine.
GPL: commercial use is ok only if the product is also open source.
LGPL: commercial, proprietary use is probably ok, but you must release as OS any changes you make to the library itself, and you might have to provide object files that can be re-linked with a newer version of the library. (It’s a bit ambiguous wrt embedded software. Note that most of the arduino core and libraries are LGPL.)