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LED driver to drive 8 LEDs with 8 GPIOs

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muthukural001:
Hi,

I need to drive 8 LEDs with 8 GPIOs (Each GPIO for Each LEDs. I thought of having 8 transistor where GPIOs is connectied at the base of the transistor to drive these LEDs. Instead of having 8 transistors, there is any single chip solution to do this?...Please suggest.

Thanks and Regards,
Muthu

greenpossum:
You can use a 74HC595 to drive the LEDs and clock in the data serially which means you can use 3 or 4 GPIO outputs. See this project which drives up to 16 LEDs. You only need to implement half of it: https://hackaday.io/project/168654-an-uninnovative-linear-led-display

Ian.M:
Insufficient data:

LED Vf?
Desired LED If?
Supply voltage?
Logic Vcc?

ebclr:
A simple 330 Ohm resistor will do the Job, in most CPU's. without any transistor,

spudboy488:
As others have said, not enough information. The method will be different depending on the specifications of the components used.

Generally:

The CPU can directly drive the LED anode with a current limiting resistor depending on the CPU pin current spec and overall CPU current spec.

There are instances where the CPU can sink more current than it can drive. In these cases, the CPU can directly sink the LED cathode with a current limiting resistor depending on the CPU pin current spec and overall CPU current spec.

The CPU can drive a ULN2803 (or equivalent) 8 channel transistor array which can sink the LED cathode with a current limiting resistor.

You can use port expanders, shift registers, etc. but those would still fall under the same rules as directly driving with the CPU.

More info would make it easier to answer.

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