Hedge The North

View of Live Dashboard Web Interface
Trading Interface on Hacker Badge

Inspiration

Hackathons are full of chaos worth betting on: who wins Best Use of AI, how many Red Bulls get drunk, whether anyone actually sleeps before demos. We wanted to turn that chaos into a live, on-chain prediction market that runs during the event itself, leveraging the Hacker Badge's Bluetooth capabilities and Solana's blockchain technologies.

What it does

Hedge The North lets attendees place bets on real things happening throughout the hackathon: category winners, sponsor-tied stats (like total energy drinks consumed), and community-submitted prop bets. Markets are created two ways: sponsored & competitive results are created by organizers, and community-submitted bets can be approved by the same organizer committee. Outcomes are resolved by a trusted organizer multisig.

How we built it

Solana program handles market creation, market making, bet placement, resolution
Organizer multisig Event organizers input win/loss conditions with agreement required
BLE hardware integration via the provided Lua API: device taps/scans feed structured events that auto-instantiate pre-templated transactions (e.g. "Will Team X place top-3: YES")
Lightweight moderation queue for community-submitted markets, simply submit a detailed request and your organizers will accept/reject as they see fit
Frontend for browsing markets and placing bets, synced to on-chain state in real time

Challenges we ran into

Porting our initial design onto the Hacker Badge, we quickly ran into a memory ceiling. The wireless stack alone consumed most of the available space, leaving no room for our program logic. We dug into manual memory management to get back just enough headroom to get wireless working alongside the rest of the firmware.

Choosing the right wireless protocol was its own hurdle: each protocol proposed tradeoffs such as range, power draw, and bandwidth. We settled on Bluetooth for both user-user interaction and our live sync for its ease of use and existing Hacker Badge communications. On top of that, the Lua API's documentation was sparse in places, so a fair amount of the integration work came down to trial and error rather than a clear reference path.

Accomplishments that we're proud of

Watching a Hacker Badge tap trigger a brand-new market event appearing live on-chain was extremely rewarding the first time. Solana was chosen specifically with this real-time update in mind. Hackathons move fast & change fast, so we needed a speedy & inexpensive way to update our data on the fly. Getting that physical-to-chain bridge to actually fire in real time, reliably, felt like the payoff for everything else we built around it.

What we learned

We learned how much of a prediction market's integrity comes down to resolution design, not bet-placement mechanics; the trading logic was the easy part compared to designing a trustworthy, low-latency way to decide who won. We also got hands-on experience connecting physical hardware events directly into on-chain program instructions and learned to treat automated and manual market creation as the same code path so nothing skipped the resolution-source requirement.

What's next for Hedge The North

Permissionless market creation with staked bonds, richer community-sourced bets (possibly LLM-assisted drafting from live event chatter), and a public leaderboard tracking best predictors across future hackathons.