Arduino

Build FETCH: An Open Source AI Robot Powered by Arduino UNO Q

Arduino® UNO™ Q 4GB

Arduino App Lab

<html><body> <figure><img src="https://projects.arduinocontent.cc/9168c644-044f-4108-bf90-ee9cdb607ab6.png"/><figcaption></figcaption></figure> Meet FETCH, an open source AI powered robot built around the Arduino UNO Q. FETCH combines robotics, artificial intelligence, and 3D printing into a compact, interactive robot that makers can build and customize themselves. The goal of this project was to create a robotic companion with a unique personality while keeping the design accessible to hobbyists. Rather than requiring custom circuit boards or specialized manufacturing equipment, FETCH uses readily available electronic components and 3D printed parts. In this tutorial, we'll cover the main components, mechanical design, electronics, assembly process, and software setup needed to bring FETCH to life. For those looking to build their own, the complete assembly manual, bill of materials, electrical schematic, 3D-printable files, and software are available as supporting resources. <h3>1. How FETCH Works</h3>At the heart of FETCH is the Arduino UNO Q, which provides the processing and control capabilities needed to run all of his functions. FETCH integrates several different systems into one compact design. Arduino UNO Q The Arduino UNO Q serves as the central controller for FETCH. It runs the robot's software and interfaces with the various electronic components responsible for movement, sensing, and interaction. Movement and Articulation FETCH uses a dual motor drivetrain to move around his environment. A set of servo motors controls its articulated arms and antenna-like ears, allowing him to produce expressive physical movements. The arm mechanisms use a combination of servo motors, custom 3D-printed components, and mechanical linkages. Visual Input A USB camera is mounted on the underside of FETCH's body, providing visual input for its custom AI object detection model. Display and Audio A 3.5-inch display is integrated into the front of the robot to display face animations. FETCH also incorporates left and right speakers paired with a DFPlayer Mini module for audio output. Power System Fetch runs on a 2200mAH battery. Two XL4015 buck converters supply regulated power to the electronics. A fuse holder, power switch module, and voltage sensing module for safety and sensible power management. <h3>2. Components and Materials</h3>FETCH uses a combination of off the shelf electronic modules and custom 3D printed components. Below are some of the primary electronic components used in the build. Arduino UNO Q 4GB - m ain computing and control platform 3.5-inch display - animated face USB camera - visual input MG996R servo motors - articulated shoulder movement MG90S servo motors - smaller articulated mechanisms like ears and elbow joints TB6612FNG motor driver - drive motor control XL4015 buck converters (2) - voltage regulation DFPlayer Mini - audio playback 2W, 8-ohm speakers - sound output USB hub	USB - connectivity Voltage sensing module - battery voltage monitoring Power switch module - power control TT Drive Motors - dual wheel drive trainBattery - portable power Additional components include DC drive motors, wiring, connectors, a fuse holder, screws, O-rings, and 3D-printing filament used as hinge pins. A complete bill of materials, including component quantities and specifications, is provided separately. Required Tools Most mechanical components are designed to snap or slide into place. However, some assembly operations require: •	Small Phillips-head screwdriver •	Metric hex keys •	Needle-nose pliers •	Wire cutters and strippers •	Soldering iron and solder •	Heat-shrink tubing •	Digital multimeter •	Hobby knife or deburring tool <h3>3. Designing FETCH</h3>One of the biggest design considerations for FETCH was fitting all the necessary electronics into a compact robotic body while keeping the assembly process manageable. Instead of constructing a traditional rigid frame and installing components individually, FETCH uses a modular internal structure. The electronics are mounted to individual 3D-printed panels that connect using hinges. Once all the components have been installed and wired, these panels fold together into a cube shaped body. This design provides easier access to the electronics during installation and simplifies the final assembly process. Most parts are held in place using integrated slots, clips, and sliding features which reduces the need for additional hardware. Even the hinges use sections of standard 1.75 mm 3D printing filament as pins. <h3>4. 3D Printing the Components</h3>FETCH was designed around 3D printed mechanical components, allowing builders to manufacture most of the robot's structure using a consumer 3D printer. These include the outer shell, internal electronics mounts, wheel assemblies, motor housings, arms, servo covers, and other structural components. Before beginning assembly, print all the required components and verify that the parts are free of major defects. Remove support material, clean up any excess filament, and inspect snap-fit connections. Depending on printer calibration and tolerances, some sliding or snap fit connections may need minor cleanup. <h3>5. Installing the Electronics</h3>The first major assembly stage involves installing the electronic components into their respective mounting panels. The internal assembly is divided into front, back, left, right, and bottom sections. Each section holds a different group of components. <figure><img src="https://projects.arduinocontent.cc/9db35bfa-179d-4657-9644-6ff8abbaa083.png"/><figcaption></figcaption></figure> Front Assembly The front panel holds the Arduino UNO Q, display, motor driver, power switch module, power distribution modules, and voltage sensing module. The display slides into its mounting slot, followed by the remaining electronic modules. A 3D printed clip secures the TB6612FNG motor driver. Some components are difficult to access once installed, so it may be easier to connect their wiring beforehand. Side Assemblies The side panels accommodate the servo motors responsible for FETCH's articulated movements. The left assembly also contains a speaker and DFPlayer Mini module. Included in the Fetch download are the audio files for the DFPlayer Mini. The player requires a micro SD card with files to play. At this time transfer the Fetch audio files onto the micro SD card and insert into the DFPlayer mini. The servo motors are secured using dedicated 3D printed covers that slide into place. Bottom Assembly Two XL4015 buck converters snap into dedicated slots in the bottom panel. These modules are used to regulate voltage for the robot's electronics. Rear Assembly The rear panel houses the USB hub and fuse holder. The USB hub's outer enclosure is removed, allowing its circuit board to be installed directly into the custom mounting tray. <h3>6. Connecting and Wiring the Internal Assembly</h3>Once the electronic modules are installed, the individual panels can be connected together. Each panel is joined using filament hinges. Cut short lengths of 1.75 mm 3D printing filament and insert them through the hinge connections to secure the panels. The fit should be snug. If necessary, the ends can be crimp with a needle nose pliers to prevent the pins from sliding out. Before folding the body together, complete the required electrical connections. Most signal connections use DuPont wires, while some components require soldered connections. Certain wires, including those for the drive motors and elbow servos, must remain long and accessible for connection later in the assembly process. Refer to the electrical schematic for all wiring connections. Important: Before connecting the full circuit, the XL4015 buck converters must be adjusted to the appropriate output voltages using a multimeter. Their output settings should be verified before connecting sensitive electronics and checked again under load. Refer to the assembly manual for specific details. <h3></h3> <figure><img src="https://projects.arduinocontent.cc/4e043187-a9d6-4e1c-b95e-6552954d2db8.png"/><figcaption></figcaption></figure> <h3>7. Folding and Closing the Body</h3>With the electronics installed and wired, the internal structure can be folded into its final cube shape. Carefully fold the hinged panels together, ensuring that no wires are pinched between the panels. The rear panel clips into the side panels, forming the enclosed electronic cube assembly. The completed electronic assembly then slides into the rear outer shell using integrated dovetail features. Route the servo wires, motor wires, USB connections, and camera cable through their designated openings. The battery tray also slides into the rear shell assembly. Use a piece of tape to hold the power button in place on the front outer shell. Finally, place the front shell over the internal assembly and secure the enclosure using four M3 × 5 mm screws. Remove the tape from the power button. It should now click and move freely. <figure><img src="https://projects.arduinocontent.cc/63d62ccf-ee2e-4937-b806-471296478196.png"/><figcaption></figcaption></figure> <h3>8. Building the Drivetrain</h3>FETCH uses a compact two wheel drivetrain mounted beneath the main body. Each drive motor fits into a custom 3D printed motor casing. The motor covers snap into place, securing the motors inside their housings. Each wheel uses a 3D printed hub with O-rings fitted into grooves around the circumference to provide traction. The wheel hubs are then press fitted onto the motor shafts. A separate balancing assembly uses small rotating wheels and 3D printing filament pins. Once the individual components are assembled, the balancing mechanism is fastened to the drivetrain using M3 screws. The completed drivetrain slides onto the underside of FETCH using integrated dovetail connections. The motor wires are soldered to the wires coming from the main body and insulated using heat-shrink tubing. Filament pins prevent the drivetrain from sliding out of its mounting channels. <figure><img src="https://projects.arduinocontent.cc/f0085a72-99ee-4805-9679-90f09a240059.png"/><figcaption></figcaption></figure> <h3>9. Assembling the Arms and Ears</h3>FETCH's arms are among the more mechanically involved parts of the assembly. Each arm consists of a shoulder section, upper and lower arm components, servo motor, servo cam, mechanical linkage, and hand. The shoulder mounts directly to a servo shaft extending from the side of the body. Another servo drives the elbow mechanism through a custom cam and linkage. The linkage is bent into its required shape using a 3D printed guide for reference. Once the servo and linkage are installed, the outer arm covers snap into place. The antenna like ears are installed by pressing them onto their respective MG90S servo shafts. <figure><img src="https://projects.arduinocontent.cc/962e277c-cce2-4d9d-abe2-5165f34130b3.png"/><figcaption></figcaption></figure> <h3>10. Programming FETCH</h3>With the hardware assembly complete, the final step is installing the software. FETCH uses Arduino App Lab to run its application on the UNO Q. For the initial setup, connect an external monitor to the HDMI port on the back of FETCH. A Bluetooth keyboard and mouse are also useful for navigating the setup process. Initial Setup 1.	Install the battery and power on FETCH using the front power button. 2.	Follow the on screen instructions to configure the UNO Q. 3.	Connect the system to Wi-Fi. 4.	Open Arduino App Lab. 5.	Download the FETCH application from the provided project files. 6.	In App Lab, select Import App and import the FETCH application. 7.	Open the application's options menu and select Run on Startup. 8.	Once the application is installed and configured, shut down the UNO Q and disconnect the external display. 9.	FETCH can now be started using its built in power button. <h3>11. Testing and First Run</h3>Before allowing FETCH to operate freely, perform a final inspection of the completed assembly. Ensure the electronics are securely installed and all wiring is connected correctly. Verify that the regulated power outputs are set correctly and remain within the required range under load. Check the arm linkages, servo connections, and drivetrain for mechanical interference. Once everything has been checked, place FETCH on a flat surface and power it on. The UNO Q will boot and launch the FETCH application automatically if the startup option was configured correctly. FETCH is now ready for its first run! <h3>12. Project Files and Documentation</h3>FETCH is intended to be an open-source platform that makers can build upon and customize. The following files are provided to support the build: • Assembly Manual : Detailed step by step instructions with exploded CAD illustrations. • Bill of Materials : Complete electronic and mechanical component list. • Electrical Schematic : Wiring connections and power distribution details. • 3D Printing Files : Printable models for the robot's custom mechanical components. • FETCH Application : Software required to run FETCH on the Arduino UNO Q. The assembly manual contains additional details that may be useful during construction, particularly when installing the electronics and routing wires through the robot's body. <h3>13. Final Thoughts</h3>FETCH brings together several areas of robotics into a single project, including mechanical design, electronics, 3D printing, motor control, and artificial intelligence. The Arduino UNO Q provides the computing platform that ties these systems together, making it possible to combine traditional hardware control with AI powered software. One of the goals of releasing FETCH as an open source project is to give makers a platform they can experiment with, improve, and customize. Whether you're interested in robotics, artificial intelligence, or simply building an expressive little robotic companion, FETCH provides a starting point for exploring all three. I hope you all enjoy Fetch! Happy building! Sector 07 </body></html>

Build FETCH: An Open Source AI Robot Powered by Arduino UNO Q

Small in size, big on personality, and always ready for a game of fetch!