austin jian

Plant Hopper — 1st at Hack the Valley

PlantHopper

timeline: October 2025 • team: Sean Chan-Sato, Jason Liu, Eugene Lee

tech stack: Arduino, C++, Python, Next.js, React, Tailwind CSS, Firebase, OpenCV

Overview

Plants are good. They give us oxygen and they look cool. But.... they need to be maintained.

What if we had a robot that had a mounted turret with a water bottle attached so that it could automatically track and aim water at plants? Wouldn't it be so cool if it also could water based on moisture levels, and if you wanted to you could access a dashboard on your phone to control this turret?

Well... that's exactly what PlantHopper is. It hops around your plants and shoots water at them.

PlantHopper Turret

How it works

To be honest, I'm not much of a robotics guy but my teammates sure were. They are crazy cracked at robotics, but I don't know much. I learned what an april tag was at this hackathon lol.

Anyways I basically connected the software to firebase so that you can control the turret using any computer as long as you have the dashboard open. From what I understand:

PlantHopper is split into three layers: the turret hardware/firmware, a cloud-backed web dashboard, and a Python control layer that connects everything end-to-end.

Hardware + Firmware

  • Custom CAD turret with 2 DOF (pitch + base rotation)
  • AprilTag detection to locate each plant and calculate distance + offset
  • PID alignment + trigonometry to compute the optimal shooting angle
  • Servo-controlled, tunable water gun for precision watering

Cloud + Web App

  • Firebase backend + Next.js dashboard deployed on Vercel
  • Robot publishes soil moisture data + CV images to the database
  • Web app sends commands (water now, scan plants, fetch moisture/health)
  • Commands execute in real time via a Python threaded controller
  • Control/monitor from any device (no local setup)

Python Control Layer

A multithreaded Python script ties everything together:

  • Runs computer vision
  • Manages serial communication with the Arduino
  • Handles Firebase reads/writes
  • Oversees timing, alignment, and command execution
PlantHopper Model

Results

We won first place at Hack the Valley 2025! Thank you to my teammates Eugene, Jason, and Sean! I learned a lot working from you guys, especially about hardware, as I've never worked with hardware before. You guys are also super chill and easy to work with :)

PlantHopper Model