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Topic: first time question. LEDs on a pin (Read 536 times) previous topic - next topic

davesaint

Hello.

I'm new here, and I have just finished "hello world" with the arduino.
I'm using an arduino uno board, and I have a question.
Is it possible to light several LEDs in sequence using 1 pin, like an LED array?
In sequence, I mean, the first lights up, then goes off, then the second, etc.
Forgive me if this is a simple thing, I'm just learning and I was hoping to have this as my first project to learn


Grumpy_Mike

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Is it possible to light several LEDs in sequence using 1 pin,

No, you need one pin per LED ( don't forget the resistor ) or an external chip like a shift register, that requires 3 pins, or an I2C device that requires 2 pins.

davesaint

I thought it would be something like that.
I was hoping to do a really big light bar, 60 LEDs...

Grumpy_Mike

Why the 1 pin limit?
with 3 pins you can light up as many as you like by cascading shift registers,
You can even dim them with this software.
http://www.elcojacobs.com/shiftpwm/

davesaint

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with 3 pins you can light up as many as you like by cascading shift registers,

Again, I am super new to arduino, what is a shift register?

Grumpy_Mike


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