Nexi AI – The Smart Voice-Controlled Auto Robot

Meet Nexi, a 3D-printable intelligent companion robot featuring an active wheeled chassis, a movable head, and a built-in OLED face screen. Powered by an ESP32-S3 and connected to a cloud-based AI, Nexi can understand your voice commands, talk back to you in real-time, nod/shake its 

head, and drive around!

🔗 Project Links & Videos

• Official Website & Complete Tutorial: hdrobotics.de NexiBot
• YouTube Demo Video: Soon
• YouTube Step-by-Step Assembly Video: Soon

Note: The complete building instructions, schematics, and firmware flashing guide can be found on the website mentioned above.

🛠️ Bill of Materials (BOM)

For building Nexi, you will need the following components (purchase links can be found on the website):

1. Electronics & Sensors:

• Microcontroller: ESP32-S3 N16R8 DevKitC (or equivalent module)
• Servo Driver Board: PCA9685 16-Channel 12-Bit PWM I2C Board
• Digital Microphone: INMP441 I2S Digital Microphone Module
• Audio Amplifier: MAX98357A I2S Class-D Amplifier (with a 4 Ohm/8 Ohm mini speaker)
• Display: 1.5-inch I2C OLED Display (128x128 pixels, e.g., SSD1327)
• Distance Sensor: VL53L0X Time-of-Flight (ToF) Laser Distance Sensor
• Motion Sensor: MPU6050 6-Axis Gyroscope & Accelerometer
• Status LED: 3V Stick or compatible LED (or standard LED)

1. Servos & Motors:

• Chassis Drive: 4x 360-degree servos for continuous rotation (e.g., FS90R or equivalent)
• Head/Neck Movement: 2x 180-degree standard micro servos (e.g., SG90 or MG90S for more power)

1. Accessories, Screws & Connectors:

• Threaded Insert Set (Heat-Set Brass Inserts): Set with M2, M2.5, and M3 threaded inserts for melting into 3D prints
• Screw Set: Hex socket screws in sizes M2, M2.5, and M3 (various lengths from 4mm to 12mm)
• Connector Set (White Connectors): JST-XH (2.54mm pitch) or JST-PH (2.0mm pitch) crimp connector set for clean, stable wiring
• Power Supply: 5V Step-Down Regulator (Buck Converter) & Battery (e.g., 2S LiPo or a flat USB power bank)

🔒 Important Note on Data Privacy & Cloud Connection

Nexi is a cloud-based AI robot. This means that voice processing, text recognition, and AI calculations occur online via external servers. Audio data is transmitted encrypted over the internet for processing. If you have concerns regarding cloud technologies, external voice processing, or online AI models, you should refrain from building this project.

⚠️ Disclaimer

The replication of this DIY project is entirely at your own risk and responsibility. The creator of the project assumes no liability for damages, short circuits, destroyed components (e.g., due to incorrect voltage supply like 5V on the I2C bus), or hazards associated with handling batteries. Basic knowledge of soldering and reading schematics is absolutely essential for successful assembly