Skip to content
CompletedIoT & hardwareResearch

Automated Weeding Robot

A GPS-guided field robot that navigates crop rows and removes weeds mechanically.

Ultrasonic arrayGPSArduino MegaWi-FiDriveCutter
Role
Co-author (4th of 6)
Team
6 students — IUB
Timeline
Sep 2025 – Dec 2025
Organisation
Independent University, Bangladesh
Code
Private repository
Reading time
1 min

An Arduino Mega robot with ultrasonic obstacle sensing, GPS waypoint navigation, differential drive and a high-speed cutter. Removed 85% of weeds in the lab and 75% in the field.

Overview

Manual weeding is slow and herbicides are expensive and harmful. The robot drives between crop rows and cuts anything growing in the gap — a deliberately simple, non-vision approach that works without costly cameras or models.

The problem

  • Navigate rows reliably outdoors.
  • Avoid obstacles and people.
  • Remove weeds without chemicals or expensive machine vision.

Context & constraints

Weed detection is positional: any plant between the rows is treated as a weed.

Approach

  • Control — Arduino Mega (ATmega2560) running the navigation loop, with ESP8266 Wi-Fi for telemetry.
  • Sensing — four HC-SR04 ultrasonic sensors (2–400 cm) and a NEO-6M GPS for waypoints.
  • Drive — four 300 RPM gear motors with differential steering through BTS7960 drivers at 10 kHz PWM.
  • Cutting — a 775 motor at about 21,000 RPM.
  • Power — a 12 V, 2200 mAh lithium-ion pack for around four hours of operation.

Key capabilities

  • GPS waypoint navigation (±2.5 m)
  • Obstacle avoidance under 0.5 s
  • Mechanical, chemical-free weeding
  • ≈4 h battery life

Architecture

  1. Sensing

  2. Control

  3. Actuation

A classic sense → decide → act loop on a microcontroller. Select a component to trace its connections.

Quality & delivery

Testing

Lab and field trials measured obstacle range, GPS accuracy, avoidance delay, battery life and weed-removal rate.

Outcome

Weed removal (lab)
85%
75% in field trials
GPS accuracy
±2.5 m
NEO-6M
Obstacle avoidance delay
<0.5 s
Battery life
≈4 h
12 V, 2200 mAh

A working prototype documented in an IEEE-style paper with lab and field results.

Lessons

  • Field conditions take a real bite out of lab numbers — plan for the gap.

Building something similar?

Tell me what you’re working on — I reply to every serious message.

Related work

Motion sensorESP32 senderESP32 receiverOLED + buzzer
Completed2025Independent University, Bangladesh

Gesture-Based Messaging for Assistive Care

Two ESP32 units over Bluetooth Classic: a wearable sender with an MPU9250 motion sensor and a receiver with an OLED and buzzer. Reliable at 10–20 metres.

  • C / C++
  • ESP32