"Blinking Eyes" LED circuit. ?

A timer circuit that'll turn LEDs on and off in an approximation of eyes blinking. Ooooon-off-on-off-oooooon-off-oooooon. So, this coming Halloween, I've got a dozen or twenty of these timers, running pairs of red LEDs, about eye-width apart, that are poked through a piece of cardboard spray painted flat black and set in shadowed areas around the porch. Maybe a couple of sets of them covered with ping-pong ball halves to make the "eyes" bigger.

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swilde26 years ago
I know this is a little late, but I'm putting together something like this for my halloween this year. I'm using a Tlc5940NT. I've found that this is pretty much the easiest thing to use (assuming you have already have a spare Arduino).

The code in this project makes it pretty simple (and they even have a pretty diagram to show newbs like me how to wire it all up).


allen (author)  swilde26 years ago

And yeah, I wish you'd posted the comment some time ago but don't think I'm not grateful for you having posted the comment. Thank you.
UziMonkey8 years ago
A microcontroller could control a large number of LEDs, and control the blinking quite easily. For more LEDs than you have pins for, there is also charlieplexing, which will let you do this with really cheap microcontrollers with small pin counts. Even if you're using a 555 of something for the timer (which is a pretty cheap chip), running multiple timers with a single microcontroller will be cheaper and easier to control. I recommend the Atmel AVR chips, and/or the Arduino platform.
Charlieplexing only allows one LED on at a time, so it isn't really well suited to an application like blinky eyes, where the LEDs spend most of their time on. You can do time-slicing tricks to light them all, but by the time you get into that, you'd have been better off just slapping a shift register into the design.
allen (author)  UziMonkey8 years ago
I kind of like the microcontroller approach since I could get multiple sets of independently blinking eyes with less work. Got any more info? Web sites, specific projects, etc? I'd like to build one of these if I could as an instructable but I'm not a hardware guy so this is all foreign territory to me.
UziMonkey allen8 years ago
The easiest route would be Arduino. There are cheap Arduino clones for ~$25 like the barebones Arduino from Modern Device that'll get you started. You can use the Arduino to program individual ATMega chips to make multiple devices without additional Arduino boards. For tons of info, see the Arduino website.
canida8 years ago
You could also just use a variation on Blinky Bugs and skip the extra wiring and control system.