We Built a Haggling Crab That Pays You for Beach Trash (HackGT 13)

In this video, we build Haggle Shack at HackGT 13: Seaside Market, a wooden trash chest where you bring garbage from the beach, show it to a camera, and negotiate your reward with Haggly the Crab. The crab won't like your first offer, so you'll have to haggle. Once you've agreed on a price, you earn shellcoins and a servo trapdoor sorts your trash into recyclables or landfill. It was a messy build. Home Depot's cutter was broken, so we rode home with 2x4s held over our heads in the car. We stained the wood at the Student Competition Center, pushed a dolly a mile back to our dorm, and brought the whole floor in to cheer us on and test the crab. On the software side, we used Gemini for vision and haggling and ElevenLabs for Haggly's voice, and we cut the AI response time from about 14 seconds to under 3 so the conversation feels natural. Next up: taking Haggle Shack to real beaches and getting real data. Built with: Arduino, Python, Gemini, ElevenLabs, MongoDB, and a lot of wood stain. Subscribe for tomorrow's video :)