Thread: Converting Sound activated to Motion Activated

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Hi All,

I'm wondering if anyone has suggestions on how to convert a sound activated prop into a motion activated prop. For instance, I have the Caged Beast from Spirit and it only functions as a sound activated prop. I know some of the spirit props have plugs for footpads, but I want motion activation. This prop requires a pretty loud noise it trigger it and I doubt it'll go off very often.

My intention is to force people in my haunt to walk past it, making them get very close to the cage. I want their motion to trigger the beast just as they are in front of it. When it does go off, it's very loud and this will definitely produce a good scare!

Any suggestions?

It is possible to do something like that but the hard part is figuring out where in the circuit the activation happens. Does the prop turn on right when it is powered up? If so you might get away with adapting motion sensing to just turning on the power. Or if you could experiment with sounds that make it go off you might be able to trigger it with a nice loud sound.

So basically, is it possible?... yeah probably... but without cracking one open myself it's hard to say exactly how and it is definitely not universal as to how it is done from one electrical circuit to the next.

Was the beast expensive? I will go check it out to see if I can find an easy answer for you.

-CZ

Well the first low tech thing that comes to my mind is to use a standard outdoor motion sensor flood light. Hardware stores sell these screw in converters that go from a light bulb thread to a two prong outlet, now you have on/off AC power that is motion activated. Now you find something that makes noise when you plug it in, like a radio turned on. Plug the radio into the flood light socket either directly or with an extension cord and place the radio next to the sound sensor of the prop. When the motion detector senses motion it turns on the radio, the radio wakes up your prop. Thats the easiest way I can think of...

Originally Posted by lostskeleton

It is possible to do something like that but the hard part is figuring out where in the circuit the activation happens. Does the prop turn on right when it is powered up? If so you might get away with adapting motion sensing to just turning on the power. Or if you could experiment with sounds that make it go off you might be able to trigger it with a nice loud sound.

So basically, is it possible?... yeah probably... but without cracking one open myself it's hard to say exactly how and it is definitely not universal as to how it is done from one electrical circuit to the next.

Was the beast expensive? I will go check it out to see if I can find an easy answer for you.

-CZ

Hi CZ - Thanks for the information. To answer your questions:

- No, the prop does not turn on when plugged in. You still need to make a loud sound.
- The beast is a $199 Spirit prop ($160 with the 20% coupon I had)

It's a really nice prop and fairly unique in comparison to all the other standing props. Once activated it yells a few different phrases and always ends with a nice wolf howl. This prop would really provide a good scare if it could be triggered by motion instead of sound.

I had this same problem in 2008 with the Spirit Chin-up Zombie. It's a great prop but again they only gave it sound activation. My quick fix was to place a Striking Snake prop at the base of it. It worked really good - too good almost. The snake would go off and then the zombie would go off. But then the sound of the zombie would sometimes set off the snake again. (The snake was very sensitive to motion) It wasn't a big deal because it eventually stopped, but it wasn't ideal. You can see this setup if you go to the 30 second mark in my video:

YouTube - 2008 Scarewood Haunted House - Vid 2 - Lights On

The haunt I'm doing this year will be an even larger scale production so I really want a solution that looks and functions a little smoother.

Any input is appreciated!
- Joe

Joe, I swung by my local spirit but it wasn't open for business yet! Crazy!
I also looked through my store bought props from a few years ago but none of them are sound activated, just light activated... I will try finding a sound activated prop at one of my local stores and come up with something everyone on here can use.

Sound activated props are annoying to get to work reliably.

I will get on this over the weekend if someone doesn't beat me to it.

-CZ

I also have the caged beast & didnt realize it wasnt motion activated. I like the snake idea but I was planning on hanging him on my porch - back where you could see him but TOT's wont be able to touch him. I would love to hook up a pressure mat so when walking up the walk, he would go off.

Any way to get that working do you think? My caged beast is still in the box.

RichTJ99 - I haven't been able to think of any ideas that don't involve cracking open the case and messing with the internal parts (which isn't something I'm comfortable doing) I'm hoping CZ has some ideas.

Even if you want to keep it in the back of your porch, the snake might still be able to trigger it. It depend on how dark the porch is. My main issue with the snake method is it kills the initial scare for the TOT. The snake gets the scare and the beast is a secondary hit. It's better than nothing but still not perfect.

My beast is already in storage so I cant check it if has the TEST ME plug. If it does there might be a way to hack that and use a mat...

Alright, I stopped by a party store over the weekend and picked up a sound activated skull. And I converted it to a switch activated version. It didn't take me long to get it working well.

The first thing I found is that my sound activated prop uses a device called a Piezoelectric buzzer to sense sound. This device is normally used to make buzzing sounds or as a small speaker of sorts. It has a little ceramic plate in it that physically contorts in response to changes in voltage. It's a pretty cool little device and can do something pretty cool besides make some buzzing sounds. It responds to vibrations! (kind of using it in reverse)

Here is the piezoelectric buzzer in one of its forms:


So I know know that this is what the sound activated prop is doing, detecting vibrations in the air. The signal generated by our piezoelectric buzzer goes right to an amplifier and creates a pulse that is sent to our little chip that is buried under a black blob on my board and most of the boards I have seen in these store bought props.

So since the chip is looking for changes ranging from both positive to negative I decided to just clip off the buzzer and attach the wires that went to the buzzer to a momentary switch that is normally open. When I do something like this and I have two wires I clip the wires at different lengths so I can put it back together if I need to. This worked really well and I have it at my workbench right now and I think I have pressed the button about 50 times without a problem yet.

There is one caveat to this though, since the circuit is sensitive to very small changes, if you leave the wires bare and touch them both with your skin the amplifier on the circuit is sensitive enough to pick up the 60hz that is floating around in the air and set off the prop (people are awesome antennas). So if you are planning to do this, either put a high pass filter circuit before the switch, or make sure all the wires are nice and covered. I don't have my high pass on my unit right now so that I can test the quick and dirty solution and so far it works great.


1.)
Ok so the short answer to your question: Yes you can convert a sound activated prop to a switch operated prop. And I am guessing most sound activated props have these little buzzers as I haven't seen one that doesn't yet.

2.)
To convert it just clip off the buzzer and put a normally open momentary switch in it's place (or normally open relay or mat-switch)

3.)
The circuit is sensitive to changes so make sure you cover any bare wires or put a high pass circuit in line so you can eliminate that pesky 60hz if you touch the bare wire.



I hope this helps out, if you need any pictures or anything let me know and I can throw some up on here. I also recognize that since your prop cost 160 dollars that this might not be something you are comfortable in doing yourself and I completely get that.

If that is an issue, then I present a second solution to your problem.

Warning: buying the materials for this solution might be a bit uncomfortable for some people and there are other sources available but just not as easy as walking in and buying what you need.

Since your prop is sound/vibration activated you can use a vibration motor painted to match your prop and hot-glued to the area where the sound is sensed. This generally has good results and you can actuate the small motors with all kinds of switches and such.

Now to the potentially uncomfortable portion of the build, the purchase of the vibration motor. My favorite place to get these are adult stores, the ones I get are not phallic and look like large pills and I have used them for all kinds of great projects that have freaked people out with quick movements. The other source for these are old cell phones but it will take a bit more work to get these working right away.


I really hope this helps you and others out and if there are any questions please let me know and will be happy to clarify.

Cheers,

-CZ

CZ - I am comfortable hacking up the Caged beast but if you could provide some photos, that would be hugely helpful! I will pull him out of the box in the next day or so & take some photos of the electronics.

Is there something specific I should photograph?

Yeah I can take pictures and post them up here, I will try to get them up tomorrow.

As far as what we need for pictures of the electronics in the caged beast it would be helpful to get the sound sensor and the the circuit board. There seems to be a lot of similar boards in many of the props I have pulled apart so hopefully by looking at what is inside the beast we can easily identify all your parts. When I am modifying store bought props I always make changes that can be undone if we want to change it back.

I am going to make a mat-switch tonight when I get home to test this out as I have only tested it with a momentary switch.

I look forward to seeing the inside of the caged beast.

Cheers,

-CZ