Thread: Ghostly Footprints

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I'm starting this thread to allow Mr. Grimsley's "Dead Ringer" thread to get back on track. His idea for a ringing coffin bell evolved into a brainstorming session on how to create glowing and fading "footsteps" walking around a graveyard. I like Grimsley's concept and it needs to keep going in it's original location. So, with that said -

Long story short, I came up with a LED chasing/fading circuit based on a cheap board that's available at All Electronics. After working with it for a while, it was obvious that many new parts and some hacking would be needed to get this effect to work reliably. By the time you got done, the cost would be around $25 - $30, not including the LEDs, the wires, and a control system (555 timer circuit or similar) to turn the thing on and off.
I had been in touch with Jeff at Simple Circuit Boards to get some advice on an auto-shutdown method I was working up, and he mentioned that he could do this effect using a PIC-based circuit. He sent me a layout of the prototype and I think it looks very good. Easy to trigger, shuts off automatically after lighting and fading LEDs 1 through 10, and no assembly required except for the LED wires. The user would supply the current-limiting resistors (value dependent on the chosen LED), the LEDs and the wires. And, of course, the feet. He and I are tossing some details back and forth at this point, but he should have pricing info available very soon. Jeff could also supply the LEDs and wires for an additional price.

More to come...

I'm very interested in this project...keep us updated, Otaku!

When you say we would have to provide feet, what are you thinking of (I mean, I've put a lot of myself into my props before, but...)?

Originally Posted by Mr_Chicken

I'm very interested in this project...keep us updated, Otaku!

When you say we would have to provide feet, what are you thinking of (I mean, I've put a lot of myself into my props before, but...)?

LOL! That would be the acrylic "footprints" that the LEDs light up. I know what you mean, I'm lucky to not have left some appendages in my props, too.

I'll update as I get more info from Jeff.

So I'm picturing a frosted piece of, say, 1/8" acrylic sheeting cut in a foot shape with a hole drilled in one side for the LED...is that close to the mark?

You got it, Mr. C. If you were usng 1/8" sheet you'd need to use T1 (3mm) LEDs. For a 5mm LED you'd need 1/4". The LED should probably go in the heel of the footprint, but the best location is still being looked into.

1/4" sheet with a 5mm LED only gives about 1/16" of acrylic around the LED. Do you think that's enough?
My first thought was the heel, too, but I think you'll get more even lighting if you put the LED on the side of the foot.

Let me start by saying I'm a big fan of Jeff's stuff and have been using it for years.

If you can live with a max of 7 footprints, an alternative would be a Prop-1 from EFX-Tek. The cost would be $40.

I'm sure that the guys at EFX-Tek would write the program if you need it.

Otherwise, it seems to be a simple program to write. Watch for the trigger event, pwm the lep up on the first step, pause, pwm down..... rinse and repeat for each step. The advantage to the Prop-1 is that you could adjust how long each foot step took and how fast the footprint fades in and out based on your preferences and condtioins.

With the ULN onboard to handle current you can drive several LED's per footprint.

Just and alternate idea

SteveC/ScaryTinker

Originally Posted by Mr_Chicken

1/4" sheet with a 5mm LED only gives about 1/16" of acrylic around the LED. Do you think that's enough?
My first thought was the heel, too, but I think you'll get more even lighting if you put the LED on the side of the foot.

Sure, plenty of room, but you'll need to pretty handy with your drill. Low speed, slow feed - acrylic melts easily when drilled. The best location probably will depend on the LED. A clear-case LED will have a more focused beam and will project further into the acrylic.

what about phosphorescent painted footprints along and blacklight system that would travel along the prints? just a thought...

Thanks for giving this it's own thread