Seren holding the yellow lotus-shaped Sober Buddy host in front of a teal backdrop

Sober Buddy: An AI Player That Joins the Table

Role: UX Engineer
Team: Peter Kweon, Seren Kim, Jeewon Kim, JuJu Kim
Event: HARD MODE: Hardware x AI Hackathon, MIT
Built with: Raspberry Pi, ESP32, Arduino, OpenAI

Party games fall flat when there aren’t enough people. We built a physical AI player that joins the table and keeps the game going by listening, giving clues, voting, and sometimes bluffing.

Hardware x AIESP32Hackathon

Devpost GitHub

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At a glance

1lotus-shaped AI host at the center of the table
4leaf-shaped LED coasters, one per player
5ESP32 boards talking over ESP-NOW
1AI player that listens, gives clues, votes and bluffs

Inspiration

What if the AI could lie, too?

Social deduction games like Mafia or Imposter are fun because they run on deception, bluffing and reading other players.

We were curious what would happen if AI joined these games not just as a moderator, but as a player who can tell convincing lies. Sober Buddy explores AI as a playful social participant, and pairs it with a physical tabletop so game nights feel more interactive, surprising and fun.

Seren wiring a coaster board on the floor while a teammate codes on a laptop, reflected in a glass panel

What it does

A lotus host, leaf coasters, and an AI that bluffs

Sober Buddy is an AI-powered social game where the AI is both the host and a player. In the first prototype it plays an Imposter-style game, generating clever lies and talking with players as the round unfolds. It remembers players and greets them by name.

Lotus host

A red, leaf-patterned 3D-printed coaster with an LED and USB cable

LED coaster

The lotus host surrounded by red coasters holding shot glasses

At the table

How a round feels

The lotus-shaped central device runs the game and shows prompts like “next player, please come.”
Each player has a leaf-shaped coaster. Its LED lights up to guide turns and signal interactions.
The AI listens, gives its clue, votes, and sometimes lies to stay hidden.

Watch the full demo ↗

How we built it

AI software meets physical computing

A Raspberry Pi runs the AI and the game logic. It talks to the table through an ESP32 bridge, which wirelessly lights the right coaster at the right moment.

Raspberry Pi

Runs the AI player (OpenAI LLM): dialogue, clues, votes and lies

ESP32 Nano bridge

Receives CMD,target,command over serial

ESP-NOW

Wireless packets to one coaster or all at once

4 ESP32 coasters

Each turns its LED on or off to cue that player

The team on the floor flashing the red 3D-printed coasters, seen from the stairs

Seren handing a board to a teammate coding on a laptop, among cables and parts

Challenges

Teaching a machine to bluff, on time

Convincing deception

Unlike rule-based games, lying well needs flexible, context-aware responses. Designing how the AI could bluff believably was our biggest challenge.

Hardware ↔ AI sync

We had to keep Arduino/ESP32 signals in step with the AI’s turns, and design LED feedback that clearly communicates what’s happening in the game.

Outcome

A playful character, not just a tool

What we’re proud of

A working prototype that combines AI gameplay with a physical tabletop interface.
AI that joins a social game as a playful character rather than a utility.
A cohesive experience where hardware, AI dialogue and game design work together.

What we learned

AI can act as a social participant, not just a background system.
Physical interaction makes digital experiences feel more engaging and collaborative.
Pairing AI with hardware opens up new ways to design playful social experiences.

What's next

From one game to a platform

The prototype focuses on an AI Imposter game. The long-term vision is an AI-powered social game platform, exploring AI as a new kind of playful companion at the table.