The IS Department Haunted Pumpkin

John Gallaugher
2 min readOct 5, 2018


Boston College Fulton Hall 460 has a haunted pumpkin. Touch the pumpkin if you dare. The pumpkin’s ghost will detect the presence of a member of “the living” and will mock your feigned courage.

So how does it work? It’s a real, carved pumpkin, but the pumpkin has a Adafruit Circuit Playground Express (CPX) inside of it. The CPX has seven capacitive touch sensors. These sensors detect electricity, including the electricity inside any member of “the living” brave enough to disturb the spirit rumored to live within. A wire with alligator clips on each end is clipped to one capacitive touch sensor (pad A1 in the code linked below) while the other end is stuck deep inside the pumpkiny-goodness of the lid. Since pumpkins (and just about any other fruit) conduct electricity, the electrical presence of your mortal soul travels from your currently-not-a-corpse, then through the pumpkin, through the alligator clipped wire, to the CPX.

The CPX has an on-board speaker, which plays a .wav file. The device is Arduino-compatible, but it also supports easier-to-code CircuitPython. It took a while to calibrate the best touch_threshold (200 works, for now — we’ll see what happens when the pumpkin dries out, err, when the spirit within grows in strength).

The same principles are used to power the Baby Groot in my office. Code for the Haunted Pumpkin can be found at:

Happy Halloween,

Prof. Ghoullaugher (mwah, ha, ha) — Twitter: @gallaugher

My (mostly) freshmen business school students have been learning to code by working with the CPX. For more info, see:

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John Gallaugher

Boston College Prof. Tech/Business. Advises student entrepreneurs, TechTreks (S.Valley/SEA/BOS/NY,/Ghana). Book