FINAL PROJECT
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Project Video
Project Overview
The final project is an indoor delivery robot designed to autonomously transport items such as food, drinks, or small packages within office spaces. The robot includes a robust driving mechanism, a motorized door, matrix LED displays for communication, and a Time-of-Flight sensor for obstacle detection. The design focused on ease of manufacturing, affordability, and practical utility within a workplace environment.
Inspiration & References
Inspiration for this robot came from commercial delivery robots by Pudu Robotics and Starship Deliveries. These projects demonstrated polished delivery solutions for food and goods. However, this project reimagined those concepts to suit simpler, more cost-effective office deployments, using tools and fabrication methods available in the Fab Lab.
Materials Used
The robot was built using a combination of acrylic sheets, PLA filament, PU resin, and wood. Electronics included microcontrollers (ESP32-C6, ATtiny1614, ATtiny3216), DRV8825 motor drivers, LEDs, stepper motors, and sensors. All PCBs were designed and fabricated in-house, with electronic parts sourced from the Fab Lab and online marketplaces.
Processes Used
Key fabrication processes included 3D printing, laser cutting, PCB milling, acrylic bending, molding and casting, and CNC routing. The Zund machine was used for precision wood routing and shaping the robot's base. These processes enabled rapid iteration and customization of all structural and functional components.
Electronics
Main Board
Built around the XIAO ESP32-C6, this board handled Wi-Fi communication and served as the master controller. It interfaced with the motor, LED, and sensor boards through I2C. The board also included logic-level shifting to adapt 5V peripherals to the 3.3V ESP32 logic.
Motor Control Board
This board, based on ATtiny3216, drove five stepper motors using DRV8825 drivers — four for locomotion and one for the door mechanism. It featured I2C communication, improved solder pad design, and compact double-sided layout.
LED Control Board
Controlled by an ATtiny1614, this board powered a NeoPixel strip and 12V neon LEDs. It was designed to manage lighting patterns based on received I2C commands. JST headers were included for modularity.
Power Distribution Board (PDB)
The PDB supplied power to all modules. It stepped down 12V from the LiPo battery to 5V using a buck converter. Terminals allowed distribution to multiple subsystems. A 3D-printed XT60 mount was added for safety and reliability.
Design
The robot’s design was fully developed in Fusion 360. It included modular assemblies for the frame, wheel system, electronics housing, and door. Flat parts were optimized for acrylic laser cutting while curved shapes were formed via acrylic bending. Parts like wheel stoppers,internal brackets and curved parts of body were 3D printed for accuracy and fit.
Assembly
Base Assembly
The base was CNC routed from 12mm plywood using the Zund machine. Grooves and slots were milled to host the driving components, including motors, wheels, bearings, and shafts. Slotted mounts allowed for tension adjustment and alignment of mechanical parts.
Middle Assembly
The middle section is another important component of the robot. It provides a platform for the container and all the boards. It was made from acrylic sheets and press fit and mounted to the base using screws.It also acts as a structural support for the body.
Body Assembly
The body frame was built using a mix of bent acrylic and 3D printed supports. Flat acrylic panels formed the outer shell while 3D printed connectors joined the frame together. Adhesive and screws were used to assemble it into a sturdy, detachable enclosure.
Mechanism Assembly
The door mechanism featured a gear system powered by a stepper motor. It was made from acrylic sheets and mounted using bearings. The two gear were acrylic cut and one gear was 3D printed and integrated with the bearings and screws to ensure smooth and precise motion.
Wiring
All boards were connected using JST cables and pin headers. Stepper motors, LED strips, and sensors were wired with consideration for neatness and modularity. Wires were routed under the base and along grooves, held in place with zip ties and adhesive mounts.
Testing
Each module was tested independently and then integrated. The door mechanism was calibrated based on step count, motors were tuned for current and speed, and I2C communication was verified. Full system tests ensured obstacle detection, display animations, and control functions operated as expected.
Bill of Materials (BOM)
The BOM includes all electronic and mechanical components used in the final build — from microcontrollers and sensors to raw materials like wood, PLA, and acrylic. A compiled list is shown below.
