# Skull Hack



## CoolDJTV (Jun 28, 2011)

Is the prop in the video above a possible victim for a talking skull hack?

Let me Know

Thanks!

(P.S. I hope this is in the right category)


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## Otaku (Dec 3, 2004)

Nice prop! I assume that you just want to be able to make it say what you want it to. I think that's very possible by using something like a single channel LED light organ circuit and a MP3 player to drive the jaw motor. However, I don't know what effect disconnecting the existing jaw motor wires would have on the rest of the electronics. I think you probably can't just have the original leads left floating without some kind of load on them. Anyone else have some thoughts on this?


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## Chuck (Oct 10, 2009)

Otaku said:


> Nice prop! I assume that you just want to be able to make it say what you want it to. I think that's very possible by using something like a single channel LED light organ circuit and a MP3 player to drive the jaw motor. However, I don't know what effect disconnecting the existing jaw motor wires would have on the rest of the electronics. I think you probably can't just have the original leads left floating without some kind of load on them. Anyone else have some thoughts on this?


That was my thought also. I just hacked a gemmy skull with a light organ. Ultimately I ended up removing all the stuff inside, but before I did I forgot i still had batteries in it and the original circuit still worked fine with the motor disconnected, i.e. The eyes still lit an the sound played.

My only thing with this prop is determining the voltage needed to run the motor. My guess is 5v should be fine.


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## Otaku (Dec 3, 2004)

I just ordered a LED light organ that looks very hackable for use with skull props. It runs 4 LEDs in series so it has a reasonable voltage output. It does have an electret mic on the board, but that's the same type as was used on the talk-thru Boris. I'm thinking that the Boris hack could be used to mod this board to accept a MP3 player input. I'll have it in a few days. More to come.

Here's the LED thingie:

http://www.frys.com/product/5417939?site=sr:SEARCH:MAIN_RSLT_PG


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## pshort (May 6, 2008)

Do those props use servos or motors with simple limit switches (in general, not that specific prop)?


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## heresjohnny (Feb 15, 2006)

COlor organ circuits should work. There is also an extensive thread started by Dr Morbius on the subject. I have had a lot of luck with the Scary Terry circuit also http://www.hauntforum.com/showthread.php?t=24293&highlight=gemmy+skull


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## Otaku (Dec 3, 2004)

pshort said:


> Do those props use servos or motors with simple limit switches (in general, not that specific prop)?


The Boris uses a simple DC motor that's either on or off. It has a string wound around the shaft that pulls the jaw open when power is applied, and a spring rewinds the string and returns the jaw when it shuts off.


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## Otaku (Dec 3, 2004)

Good news. I built out the RS LED board and tested it with an MP3 player. Everything works as expected. I removed the electret mic and soldered a 100uF cap to the voltage+ side to block the ~5VDC that was going to the mic. I just need to attach a stereo jack to the cap/board and solder a 2-pin connector to the former LED pads and it's done. I can post a quick how-to if any are interested. BTW, this board is quite small, about the size of it's 9 volt battery holder. Very easy to stash inside a skull. You'd want to run wires out to the battery holder to make changes easier. A 9VDC regulated wart would work with this board, as well.


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## CoolDJTV (Jun 28, 2011)

Thanks SOOOO Much for all the help! You Guys are Genuis! Thanks So much!


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## hedg12 (Jul 6, 2008)

Otaku said:


> Good news. I built out the RS LED board and tested it with an MP3 player. Everything works as expected. I removed the electret mic and soldered a 100uF cap to the voltage+ side to block the ~5VDC that was going to the mic. I just need to attach a stereo jack to the cap/board and solder a 2-pin connector to the former LED pads and it's done. I can post a quick how-to if any are interested. BTW, this board is quite small, about the size of it's 9 volt battery holder. Very easy to stash inside a skull. You'd want to run wires out to the battery holder to make changes easier. A 9VDC regulated wart would work with this board, as well.


I just picked up one of these from Radio Shack last week to try this very thing - glad to know it works!


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## Otaku (Dec 3, 2004)

Yep, it sure does (so far). I still need to test it with an inductive load, but I don't expect any surprises. The crappy mic that comes with the kit will fool you into thinking you have a bad board - it's really inconsistent. Once I attached the MP3 player, the circuit started behaving nicely. I tested it with a beep track and the LED response was crisp and well-defined.


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## ouizul1 (May 22, 2010)

Otaku said:


> I can post a quick how-to if any are interested.


Always interested!!


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## tanalos (Jul 22, 2011)

I agree this would definitely work, basically all these props are is a giant Teddy Ruxpin bear from the 80ies and feasible for alteration.


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## Otaku (Dec 3, 2004)

It seems that the LED board has the voltage output required to run a motor, but is short on the amps. Unless I'm missing something, I think I need to cut in a 2N2222 to switch a 5-6VDC power source to operate the motor.

Jason, your thoughts?


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## Otaku (Dec 3, 2004)

Got it working. The additional parts required are a NPN transistor (2N2222 or MPSA13 Darlington), a 100uF e-cap, a 9 volt battery snap and a 1K resistor. I used a couple of 2-pin Molex connectors to make it easier to plug in the jaw motor and the sound source. I'll get pics and some instructions posted as soon as I get the time.


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## Otaku (Dec 3, 2004)

I finished the how-to for the LED light organ board hack. It's easy and requires only a few additional parts. The how-to is in a Word document, the pics are too big to upload here, and there are detailed instructions and call-outs. I found it easier to do it this way. If interested, PM me with your email and I'll send you a copy. I'm still working on doing the Gemmy skull portion but will have that in a few days.


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## Ulfilas (Nov 1, 2012)

I can get that same sound to light project kit from maplin electronics here in the UK.http://www.maplin.co.uk/sound-to-light-led-22545
Do you think this might work with my Frankie head?


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