Here is the circuit..
and those are the specifications..
Resistor: from 70 to 82 ohm (i found 82 ohm)
infrared led: 1.3-1.8V & 10-20mA
USB: 5V

well, i did it and it’s working well.. and i discovered that i bought 2 burned out led on 4.. :\

tomorrow i’ll go to buy some new led and i’ll start to craft a better bar.

everything will be documented 🙂