How can I setup 5mm leds (white/blue) 3.0 or 3.2 ma with a usb. I want use as a backlight. Help me?

Try several LEDs in parallel, with a 100 Ohm resistor to EACH ONE.
Do you mean mA or V ? Most LEDs I've met need 10s of mA to work.

scooter2013 (author)  steveastrouk5 years ago
I want to use these LEDs from amazon. http://www.amazon.com/microtivity-Clear-Blue-Resistors-Pack/dp/B004UZCADG/ref=sr_1_14?ie=UTF8&m=A2E0IHQCUI9LTK&s=generic&qid=1325176601&sr=1-14
scooter2013 (author)  steveastrouk5 years ago
3.0 or 3.2V