LASER for CR10

I wanted to transform the stock CR-10 in a laser engraver machine but using a more powerful laser than the one you can buy from Creality.
I then purchased a 5.5W laser from aliexpress with TTL input.
the stock CR10 has a second port for fan (which is a replica of the first one).
The fan output is PWM (12V), while the TTL input of the laser was 5V, you can find also laser with 12V TTL, but I found them after I bought mine.

you can translate the 0-12V to 0-5v with a simple trimmer and a test