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# How to make a 2-row Sequential LED flashing circuit? Answered

I want to make a circuit that lights up two LED's then turn them off then lights up the next two LED's and so on. I want it so it looks like the light is scrolling across the LED's. I know how to do this with one row but how do I do it with two rows so that the two row are in sync?

*Update: August 8, 2013*
I have a ramp for my R/C car with 2 rows of 6 LED's. I want the bottom two to light up, then turn off. Then the next two above them to light up, then turn off and so on. As if the light was travel from the first two LED's, to the second one, to the third, to the fourth and so on. Then have the light come back to the start. I'm also really new to electronics so, if possible, try to keep it as simple as possible.

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## Discussions

Just use 2 LEDS per channel for your needs, PIC #1
Move pin 15 to Q5 pin 10 for 3 channels etc etc

Use a 555 timer PIC #2 for 6 channels  but use pic 1 for dual led pairs.

So you're just saying use a six channel relay and connect two LED's to each channel?

Correct !
Just run wires across your pattern so both LEDs are tied across each line.

That 240 ohm resistor is for two red LEDs.
If you want to use White or blue LEDs that resistor will need to be a lower ohms value.

Each LED COLOR has a different forward voltage drop and
maybe a different current requirement
which will need to calculate a different resistance value.

So you always want a LED in one row and a LED in  the other lit together?
Simplest way is to wire the pairs of LEDs in series or parallel - Which is best will be decided by the voltage drop of the LEDs and the voltage you're driving them with.  THIS calculator shows you series and parallel setups.  (Note, the parallel setup using only one resistor is not good practice - You should have one resistor per LED, as in the single LED setup.)  The voltage drop of the LED will be in the spec sheet, but knowing the colour of the LED will give a good approximation.
Tell us more about the exact circuit.