LEO (Learning Electronic Objective)

Project overview

LEO: Learning Electronic Objective

Executive Summary & Purpose

LEO (Learning Electronic Objective) is an autonomous, AI-driven educational robot designed to serve as an interactive assistant in classroom environments and educational spaces. Built to operate independently, LEO engages students through dynamic Q&A sessions, plays audio content, and conducts structured classroom activities in the absence of a teacher. Combining custom embedded hardware, distributed microcontrollers, high-power audio engineering, and localized AI intelligence, LEO bridges hardware mechanics and artificial intelligence in an accessible humanoid form factor.

Architectural & Hardware Breakdown

Facial Expressions & Head Assembly Displays: Dual 1.3-inch OLED screens housed within the head structure serve as dynamic eyes, providing expressive visual feedback and animated states to enhance social interaction. Processing: Two dedicated Arduino Pro Mini microcontrollers drive the OLED screens independently, ensuring low-latency rendering of visual cues and eye movements without bogging down the main system bus. Neck Actuation: A high-torque MG995 metal-gear servo handles pan rotation for the head, enabling dynamic visual tracking and lifelike head movements toward participants.

Body, Frame & Enclosure Construction

Main Chassis: Constructed from durable 5 mm custom CNC/laser-cut MDF, forming a stable central structure. Front Panel: A clear acrylic front panel showcases the internal wiring, central LED indicator ring, custom PCB, and audio amplification module.

Limbs: The arm and leg structures are crafted using customized, high-durability PVC segments, keeping the overall frame lightweight while maintaining structural integrity.

Motion Systems & Kinematics Arm & Joint Control: Powered by dedicated servos across key pivot points—including 2 servos for shoulder/arm movement and 2 servos for elbow actuation—allowing gestures such as waving and dynamic positioning. Kinematic Processing: An auxiliary Arduino (Uno/Pro Mini architecture) manages low-level movement routines, generating natural, randomized idle gestures and direct kinematic responses.

Electrical System & Power Management

Custom Heart PCB: The core power distribution hub centers on a custom-designed "Heart PCB". This board hosts the main microcontroller, onboard step-up (boost) and step-down (buck) voltage regulators, and systematic power routing. Battery Pack: High-capacity custom 3S3P 21700 Samsung lithium-ion cell pack, engineered for extended operational runtime during long classroom sessions. BMS Safety: Integrated with a 40A Battery Management System (BMS) to provide overcharge, over-discharge, short-circuit, and thermal protection. Visual Status Feedback: A prominent 16-LED RGB Neopixel ring mounted on the central chest panel provides immediate visual diagnostics: Wifi Connection / Pairing: Dynamic color cycles. Online / Active: Solid state coloration. System Fault / Error: Bright alert signals.

Acoustic System Design

Amplification: A heavy-duty 2.1 channel 50W + 50W + 100W class-D audio amplifier board powers the audio subsystem. Speaker Array: 3 coaxial full-range Sony speakers for high-clarity vocal reproduction, mid-range tones, and clear playback during educational presentations. 2 down-firing Bose mid-range/subwoofer units mounted near the base structure to provide full-bodied audio performance and deep acoustic response.

Artificial Intelligence & Wireless Brain

Primary Controller: Powered by an ESP32-H2 / ESP32 series microcontroller handling Wi-Fi/Bluetooth networking and cloud-to-edge communication. AI Engine & Functionality: Integrated AI software allows LEO to operate autonomously: Interactive Q&A: Answers student queries verbally via embedded speech synthesis and cloud-assisted model capabilities. Educational Activities: Runs interactive quizzes, storytelling modules, and instructional routines when a primary educator is away. Media Playback: High-fidelity audio streaming for educational songs, lesson materials, and alerts.