Observed arrival · 2026-10-05

Otter Tutor: a robot that points out calculus mistakes

ottertutor.tech Visit website

Editorial interest 84/100 Selection signal · not a rating of the site

Otter Tutor is a desk-robot project that watches calculus work on a whiteboard and points a laser at the line where a student went wrong, offering a nudge instead of the answer.

Landing page captured for the 2026-10-05 issue.

For: Calculus students practicing derivative rules
Worth noticing: Its pin map lists GPIO assignments, servo ranges, and a laser cutoff, alongside a note about a difference between the wiring diagram and final build.

Field notes

A laptop runs the Python/FastAPI side and joins the ESP32 over a Wi-Fi WebSocket; the robot's screen is a 2.8-inch ILI9341 display, portrait at 240×320. Two SG90 servos have documented pan and tilt ranges. The build notes say the wiring diagram shows a transistor-driven laser circuit, while the finished robot instead connects the laser directly to GPIO 27, active-low.

Observed signals

Read the marks

Editorial observations of this landing page, not a rating.

○OpenPublic substance visible

✦PrettyNotable craft visible

●ProPolished or operationally mature

◎NicheUnusually specific use

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