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Plate 1 · The world on a deskGlobe 150–180 mm · about 1 : 80,000,000
Toy concept · ESP32 + stepper + servo + push-to-talk

Pointing Globe

Ask where penguins live and the globe turns by itself, the pointer slides down to Antarctica, and only then does it start telling you about it.

  • Ages 6–12
  • 10–20 minutes at a desk
  • Quiz mode for the whole family
  • ~1,000 CZK (about €40)
A printed globe with blue seas, green land and brown mountains on a dark stand, a silver meridian arc on its right and a red pointer on the arc pointing at the Himalayas, with a red push-to-talk button on the base
Plate 2

Ask the globe

Pick a question the way a child would ask it. The globe spins, slows down, the pointer slides to the right latitude, and only then does the narration start. On the right you can follow what happens between the question and the movement.

GlobeHold the red button and ask me where something is.

In the toy the child holds a red arcade button while asking. The globe never listens on its own.

  1. Heardwhisper.cpp on the Mac turns speech into text, so the child’s voice stays at home.
  2. Claude answersplaces with coordinates plus a short narration, as JSON
  3. Code checks the placeagainst a local gazetteer of countries and cities
  4. Motorslongitude becomes stepper steps, latitude becomes a servo angle

Questions and answers other than the first three are illustrative.

Plate 3

The answer is a movement

How it goes

  1. 1My 9-year-old holds the button: Where is the tallest mountain in the world?
  2. 2The globe spins, slows down, the pointer slides along the arc to the right latitude and stops on the Himalayas. Then: Here! Mount Everest, 8,849 meters. If you climbed it, you’d be on the way for almost two months…
  3. 3And where do we live? The globe points at home.
  4. 4Quiz: the globe points at a random place and asks What’s here? The family guesses and code counts the points.

Why a tenth time

Every question gets an answer you can see from across the room, and children never run out of “where is…?” questions. When they do, the quiz turns the globe into a family game where the globe asks and everyone guesses.

The raised continents are printed in relief, so small hands can also feel where the mountains are.

What AI adds

The model answers by moving a real object

Research projects already turn text into physical shape. This is a smaller, homemade version of the same idea: Claude’s answer drives a globe and a pointer, and a plain database of places keeps that movement accurate.

Plate 4

How it’s built

The globe

150–180 mm, printed as two hemispheres on the MMU: blue sea, green land, brown mountains, continents in relief.

Meridian arc

A half ring from pole to pole with a pointer carriage that an SG90 servo slides to the right latitude.

Base with a gear drive

Holds the stepper that turns the globe, a Hall sensor with a magnet for the zero position, and the push-to-talk button.

PartWhat it doesCZKPrice
Voice corelistening on button press, narration~770
ESP32-S3 DEVKitthe brain, Wi-Fi to the Gateway448catalog
INMP441 microphonehears the question98catalog
MAX98357 amplifier + 40 mm speakerspeaks the narration98 + 89catalog
Arcade buttonpush-to-talk~40estimate
28BYJ-48 stepper + ULN2003 driverturns the globe49catalog
SG90 servomoves the pointer along the arc89catalog
A3144 Hall module + magnetfinds the zero position30catalog
USB-C 5 V / 2 Apower–
Parts above ~940 CZK · concept total ~1,000 CZK (about €40)~1,000
Architecture: the push-to-talk question goes to whisper.cpp on the Mac, Claude returns places with coordinates and a narration, code compares each place with the gazetteer and uses the gazetteer when the model is more than about 300 km off, code converts latitude and longitude into stepper steps and a servo angle, the globe moves, and Piper speaks the narration Push-to-talkbutton held whisper.cppon the Mac Claude (model)places + narration Code: gazetteerover ~300 km off?use the gazetteer Code: lat/lon→ steps, servo angle ESP32 movesstepper + servo, thenspeaks Piper TTSnarration, locally

Code does

  • checks every coordinate against the gazetteer (Natural Earth countries and cities)
  • turns latitude and longitude into stepper steps and a servo angle
  • finds the zero position with the Hall sensor and keeps the quiz score

The model does

  • picks the places and writes the narration
  • gently steers questions that aren’t about geography back to the map
  • never drives a motor without the check in between
Plate 5

Safety and offline

Push-to-talk only

The globe listens only while the button is held. The child’s voice is turned into text by whisper.cpp on the Mac and never leaves the house.

Slow and gentle

The motors are slow and nothing can pinch a finger. Questions outside geography get a friendly nudge back to the map.

Quiz works offline

Places and descriptions for the quiz come from a local database and Piper speaks them locally. A question to Claude costs about 0.2 CZK.

Plate 6

Roadmap

First playable prototype

Globe, arc and quiz

The printed globe turning on its base, the pointer on the arc and the offline quiz from the local database.

Full version · 2–3 weekends in total

Ask out loud

Push-to-talk questions answered by Claude and checked against the gazetteer. The mechanics of the arc and the play in the gears are the main risk.