Wiring LEDs, making them light in sequence


#1

I built a joystick a few years back, so I feel like I should be able to wire some LEDs in a 3D design project I’m working on.

I basically want to arrange some LEDs in a circle, and have them blink consecutively, so it looks like the circle is spinning.

I’d basically need some sort of power source, battery or AC, a board to wire them to I would imagine, and some sort of timer relay or something to tell them when to turn on and off in sequence.

Any ideas? Or if nobody here knows, would you know where I could find such information? If I knew all the components I’d need, I could probably Google the process. But I don’t know what to Google for at the moment other than “LED” and that’s bringin up a billion things. I might be in over my head. =\

Here were the responses in the original thread http://www.shoryuken.com/forums/showthread.php?t=119789

Where could I get a microcontroller? There are seemingly a lot of them, and I don’t know which one to get or where I should get it from. And while AC power would be cool, it’d be even better if it could be battery powered. But how would that work? And there would be an on and off switch for the whole thing, right?


#2

http://www.ladyada.net/make/minipov3/make.html
http://www.josepino.com/pic_projects/index.pl?led_chaser.jpc

A couple of microcontroller projects that do exactly that. The Lady Ada one can even be bought as a kit for $17.50 and is made to be reprogrammed.


#3

Thanks for those links Toodles.

Crouching tiger: If you have little or no experience in electronics, I would actually suggest that you purchase the kit on lady ada and reprogram it in such a way that the lights go around in a circle (moving the LEDs into a circle as well).

If you have some expierenc, you may want to attempt to start from scratch. You can obtain a microcontroller for free as a “sample” from microchip.com. There a lot, do some research before you choose which one you want.


#4

www.auburn.edu/~goldema/clock.gif

There is a GIF slightly better explaining what I need to do. I looked at that kit, but is there a way I can do what’s in the GIF with it? Make the 8 lights light up in pairs? And in that sequence? And how would I keep the remaining 13 lights permanently lit up?

And should I get a breadboard or a PCB or something? I need a list of materials basically so I can go ahead and get this stuff started. It’s due in a week. Once I’ve got the materials, I can figure out the rest with more googling and perhaps hore help from you guys. =)

EDIT: Ugh… I’m stupid. It’s a gif, not a jpg. Link fixed.


#5

404 on the link, and you haven’t described real well what it is you’re wanting. If you can’t figure out how to use the schematics listed above to do what you want, you may want to get a simpler project.
Oh yeah, other great flashy LED links.
http://www.zws.com/products/picxie/index.html
http://www.zws.com/products/picxie2/index.html
If you decide to go with the 8x8 picxie2, you’ll probably find it easier to work with a 8x8 led matrix piece, instead of making and wiring up the matrix yourself. http://www.futurlec.com/LEDMatrix.shtml Check the voltage drop and amperage for that green 8x8, and check it against the schematic. You may need to adjust the resisters.
Looks like you will. According to the calculator at http://www.bcae1.com/led.htm , you’ll want those resisters to be about 84 Ohm each, instead of the 120 Ohm listed. (Using the values for the green matrix listed at http://www.futurlec.com/LED/LEDM88G.shtml ; 2.5V forward voltage, 30ma power, and 5V supply. If you use the 3v the schematic says with the cr2032 or a pair of AA’s, then you’re looking at about 16 Ohms, and I’m not sure if youll have anough juice. Using 3 AA’s for 4.5V, about 67 Ohms.)


#6

Crap, link fixed. =( And once you see the gif, that will perfectly explain what it is I’m trying to do. It seems like it is an extremely simple task, I just don’t know where to start. My friend who is majoring in electrical engineering is checking into it for me, but in the mean time I wanted to cover my bases so I’m trying to find answers from several places in case any fall through.

And all this circuitry has to fit within a 6" by 9" area. I’m sure that’s pretty doable. But if not, I’ll scrap the whole idea. =p

EDIT: And all these links are showing LEDs that are directly attached to a PCB or whatever. When I get all this stuff, I will be able to have the LEDs attached to a piece of wood (for example) with wires running from them to the circuitboard.


#7

Damn, this is simple, but Im still thinking 3 chips if you don’t want to go with a PIC. A 74xx93 counter, a 74xx139 2-to-4 decoder, and something to generate a regular pulse, like a 555 chip. The 555 sends a pulse signal to the counter, the counter sends the lowest two lines to the 2->4 decoder, and the blinky LEDs are wired to the output of the 2->4 decoder so only one pair is going at a time. You can put in a potentiometer in the 555 circuit so you can adjust the frequency of the pulse. The other 13 LEDs can be wired directly the power and ground with resisters, since they won’t ever turn off. No, I don’t have time to draw up a schematic for you.

Or you can use a single PIC.