I am designing a simple circuit to control 80 LEDs using the parallel port.
I am a software engineer and I barely remember the basics of hardware design. I already implemented the software to control the circuit. However now I would appreciate if someone can guide me how to build the hardware.
The following components are used for designing the circuit (a parallel port, 5 4x16 decoders, 80 resistors and 80 LEDs).
The power required to turn on all 80 leds at the same time will not be enough, right ? so I guess I need a power supply, how can the power supply be connected to the circuit ?
From what I read, the resistors are used to prevent burning the leds (since I have an output of +5 voltage), this might sound stupid but is it possible to connect the resistor before the decoders ?