Enginursday: Ghostly Gadgets – GTS Detection Device

Don't judge a book by its cover!

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A few weeks ago I had the honor of sharing my first blog post with the lovely SparkFun community.

I really enjoyed all the feedback from everyone regarding my E-Box, particularly the comment made by @FSJ Guy. Just so you know, I'm really looking into those "edible electronic treats." Seriously, because in my opinion, nothing says, "I love you" more than a box of chocolates in the shapes of my favorite passive and active electrical components. Especially if it's vegan chocolate! Nom nom nom. I know we are getting off topic here, but it's worth the mention.

This week's blog post was kind of a last-minute idea -- something quick and practical I can utilize in the field. Now for some reason I'm imagining our dialogue going something like this ...

Blog Post 2 Script

GTS Detection Device

GTS Detection Device

A device disguised as a book!

What does GTS stand for?

It's not uncommon to receive reports of footsteps, movement, or random sounds at a haunted location. Oftentimes this type of phenomenon is a personal and undocumented experience; however, I wanted to create something I could use to capture these events. A device I could simply leave in front of a video camera and watch later to see if any movement happened in a room or hallway while I was gone. The LEDs on the binding are what make this possible. The GTS Detection Device has three main components: (1) a geophone to measure ground movement, (2) a temperature sensor, and (3) a microphone for sound.

Ground movement

The geophone is an analog component that converts ground movement into a voltage to be read by something like an Arduino. For philosophical thought, if no one sees the spirit walking down the hallway, but we hear it, does it still cause the ground to move? I have no idea, but this feature would help me find out.


In the presence of a spirit many people claim to experience sudden shifts in temperature, so I integrated into the device a hot-and-cold-spot detection feature via a temperature sensor. When the device is turned on it takes an initial temperature reading. The red LED will turn on when the temperature increases +3 degrees, and the blue LED will turn on when the temperature decreases -3 degrees. The triggered LED will then stay on for 15 seconds until recalibrating itself to the new temperature of the room. During recalibration mode, both the red and blue LEDs will be on.


Since I'm not sure if the geophone would go off when reading spirit footsteps, this seemed to be a good backup to at least pick up the audio. Also, I can't tell you how many times I have been at a location and heard off in the distance random knocks or something being thrown. If you are lucky like me, you get rocks thrown at you. True story. I'm not going to lie to you about these things. What did I do? I ran, tried to flee the scene, and tripped during the process. I'm sure the spirit got a kick out of that one. It's like that moment in "E.T. the Extra-Terrestrial" when the ball comes back to Elliot, which makes you wonder -- are we dealing with spirits, or aliens?! Alas, perhaps a topic for another blog post.

E.T. Ball Throwing

I should also point out that the three components are selectable, so the user can choose to only detect vibrations or only detect sound, depending on environmental conditions and your reason for using the device.

Oh, I almost forgot a little fun fact from my building process -- this was my first time wood burning! I'm now determined to become a pro at it. Enough talk; let's ...

Watch it in action!

Until next time, the wishlist below includes several products I used to make the GTS Detection Device:

Comments 4 comments

  • LightningHawk / about 8 years ago / 1

    What an awesome tool to have in the field - Inconspicuous, useful, and nice wood burning technique!

  • They're not all chocolate, but you can find how to make some edible circuits here

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