I'm using 4 GPIO pins of my Raspberry Pi Model B 512MB Rev2.0 Board, to drive a single 7 segment LED display (1", Common Cathode, no part number on item) through a BCD to 7-segment latch/decoder/driver (HEF4511B).
Basically, VDD in the 4511 BCD Driver is connected to 5V pin in RPi. The BCD inputs to the 4511 (D0, D1, D2, D3) are from 4 GPIO pins (3.3V).
The output from the 4511 is passed through a 480 ohms resistor onto each LED segment. The circuit is set up like the first example here.
My problem is that the LED is too dim. How can I increase the brightness?
I know I could try swapping the 480 ohms resistor with a lower resistance or perhaps use transistors. Problem is, I'm afraid I might cause damage to my RPi.
I would prefer a solution with the 4511 IC itself, as I'm new to electronics and this IC is easy to understand.
EDIT: I have found this Relay driver ULN2803 which seems to be the thing to use, but I don't know how to connect it to my circuit and besides, it'll take 3-4 days for delivery.