🐾 Albert: The Modular Robot Dog Framework

Albert is a 3D-printed, ESP32-powered quadruped robot dog designed for smooth, organic movement and modular extensibility. This repository contains the core firmware built to handle complex gait cycles, inverse kinematics-style positioning, and remote control via Bluetooth.

🚀 Key Features

• Sinusoidal Gait Engine: Uses mathematical sine waves to produce fluid, lifelike walking patterns rather than jerky linear movements.
• Synchronized Interpolation: A blocking move system that ensures all legs reach their target position simultaneously, regardless of the distance traveled.
• Dual-Control Interface: Supports commands via Serial (USB) and Bluetooth (ESP32).
• Manual Override: A custom parser allows for real-time manual servo positioning (e.g., 0,325-15,400).
• Pre-programmed Poses: Built-in sequences for "Gallop," "Handshake," "Sit," and "Top" poses.

🛠️ Hardware Requirements

• Microcontroller: ESP32 (recommended) or Arduino-compatible board.
• Servo Driver: Adafruit PCA9685 16-Channel 12-bit PWM Driver.
• Servos: 8x for legs (2 degrees of freedom per leg) + 1x for the neck.
• Power: 5V High-current source (A hacked 5V Power Bank is a great budget solution).

💻 Software Architecture

The code is organized into several distinct layers:

1. Configuration: Define servo limits (SERVOMIN/SERVOMAX) and center points.
2. Interpolation Engine: moveUntilReachedAll() handles smooth transitions between static poses.
3. Gait Engine: runWalkSequence() uses a frequency/amplitude model to drive the legs in a continuous loop.
4. Command Parser: Interprets string commands into specific robot modes or manual servo movements.

🕹️ Control Commands

Commands can be sent via Serial Monitor (115200 baud) or Bluetooth Serial:

Command	Action
WALK	Walk forward in a continuous loop
LEFT / RIGHT	Dynamic turning while moving
LS / RS	Spin on the spot (Left/Right)
STOP	Immediate stop and hold current position
UP / DOWN	Adjust stand height
GALLOP	A high-energy forward lunging sequence
HAND	Perform a handshake gesture

Manual Mode Example: 0,400-1,200-15,350 (Moves Servo 0 to 400, Servo 1 to 200, and Neck to 350 simultaneously).

📈 Gait Logic (The Math)

Albert's walk is powered by a sinusoidal oscillator:

$$pulse = Center + Offset + (Amplitude \cdot \cos(t + Phase))$$

By shifting the Phase for each leg, we create the classic "trot" gait. The lift servos (odd indices) use a rectified cosine function to ensure the feet only move upward during the swing phase.

📥 Installation

1. Clone this repository.
2. Install the Adafruit PWM Servo Driver Library via the Arduino Library Manager.
3. Ensure the ESP32 Board Manager is installed in your IDE.
4. Upload the code and open the Serial Plotter to see the gait waves in real-time.

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🤝 Contributing

Albert is open-source! Feel free to fork the repo, add new gait patterns, or improve the LLM-generated logic. Created by Thinking Things.