Expressive Desktop Companion Robot

This page presents the final project — an Expressive Desktop Companion Robot: a desktop interactive assistant for company and everyday help. Planning and applications notes are in Week 17; dissemination and IP notes are in Week 18. Making and integration work continues under Week 15 (System Integration) and Week 19 (Project Development).

Final Result

I built (and am still finishing) a desktop companion robot for people who work at a desk and want a small machine that keeps company and reacts to expression and color. The look takes cues from Pixar’s Luxo Jr.; the chassis idea from sophicar; arm motion from Elephant Robotics. Most of the hardware path is in place; shared power wiring so the full system runs as one machine is still open.

Summary Slide

Video

Hero shots

Finished-system and pre-assembly hero photos are not ready yet. Concept visualization below; photo slots remain TBD.

Detail making process: see Week 17, Week 18, and (as pages fill in) Week 15 / Week 19.

Project development timeline with links

Dates below follow known week work and status from Weeks 17–18. Items without a fixed calendar date are marked planned / TBD — no invented completion dates.

• CAD — robotic arm (Week 2) — arm concept and solids; original .f3d posted on the week page. Done.
• Computer-controlled cutting — chassis process (Week 3) — laser-cut acrylic car chassis path. Done as process work.
• Electronics design — PCB (Week 6) — circuit / PCB design path; PCB.f3d on the week page. Done.
• Electronics production (Week 8) — milled board path for the project electronics. Done as documented production work.
• Input devices (Week 9) — input board kept as the final input board. Done.
• Output devices (Week 10) — output board kept as the final output board. Done.
• Interface / interactive web direction (Week 14) — interactive web page work for the project. Done as documented direction.
• Arm reinforcement (noted in Week 17 / Week 18) — done.
• Applications, implications, and project plan (Week 17) — BOM, processes, evaluation criteria. In progress / documented.
• Dissemination and IP (Week 18) — audience, sharing plan; license still open. In progress.
• Shared power wiring (planned — date TBD) — connect screen, ESP32-C3, MaixCAM, servo board, and motor board to one supply so the robot runs as one system. Incomplete.
• Summary slide & presentation video (planned — date TBD) — replace root drafts with 1920×1080 PNG and 1080p MP4. Incomplete.
• System integration / final assemble & test (Week 15, Week 19) — full demo after power is solved. Planned / TBD.

BOM list

Purchase list from Week 17 §1.5. Prices are typical Taobao listings (not a single order). Buy total about ¥556 CNY. Acrylic, Dupont wire, copper board, and solder are already in the lab (¥0). Screen, servo board, and motor board rows are the usual module class where a specific model was not locked yet.

Item	Qty	Est.	Role
Acrylic sheet, 3 mm, small cut taobao.com	1	¥0	Already in the lab. Laser-cut car chassis.
PLA filament, 1 kg taobao.com	1 roll	¥35	Arm, arm base, lamp shade
Dupont wires, 40-pin set taobao.com	1	¥0	Already in the lab. Board connections.
FR-4 copper board, about 10×15 cm taobao.com	1	¥0	Already in the lab. Milled PCB.
Solder, about 50 g taobao.com	1	¥0	Already in the lab. Board assembly.
Waveshare ESP32-S3-Touch-LCD-4, 4-inch screen taobao.com	1	¥159	Display under the shade. The board includes the ESP32-S3.
Seeed XIAO ESP32-C3 taobao.com	1	¥45	Microcontroller. Listing is about ¥45–49.
Sipeed MaixCAM taobao.com	1	¥299	Camera. Common price for the board, not the Pro.
16-channel servo driver, PCA9685 class taobao.com	1	¥13	Arm servos. Model not chosen.
Dual DC motor driver, L298N class taobao.com	1	¥5	Car motors. Model not chosen.

Questions Answered

1. What does it do? It is a desktop assistant for company and everyday help. Success means it recognizes a person’s expression and color, answers with a movement and a face on the screen, and can move around on its own.
2. Who’s done what beforehand? Chassis idea from sophicar. Arm movement from Elephant Robotics. Look from Pixar’s Luxo Jr.
3. What did you design? Circuit board (Week 6), robotic arm (Week 2), arm base, car chassis, lamp shade (screen cover), and interactive web page. The arm, arm base, shade, car chassis, and PCB are 3D designs. The Week 9 input board and Week 10 output board stay as the final boards; most other parts were redesigned. Arm reinforcement is done.
4. What materials and components were used? Acrylic sheet; PLA filament; Dupont wires; FR-4 copper board; solder; Waveshare ESP32-S3-Touch-LCD-4; Seeed XIAO ESP32-C3; Sipeed MaixCAM; PCA9685-class servo driver; L298N-class DC motor driver. See BOM above.
5. Where did they come from? Most buys on Taobao. Acrylic, Dupont wire, copper board, and solder from the lab. Datasheets for parts, test code from earlier weeks, and test files from projects close to this one were used as sources.
6. How much did they cost? About ¥556 to buy (filament ¥35, Waveshare screen ¥159, XIAO ESP32-C3 ¥45, MaixCAM ¥299, servo board ¥13, motor driver ¥5). Lab materials counted as ¥0.
7. What parts and systems were made? Robotic arm, arm base, lamp shade, acrylic car chassis, circuit and PCB, control program, screen display, and interactive web page. Week 9 / Week 10 boards reused as final input and output.
8. What processes were used?
   • 2D / 3D design: arm, arm base, lamp shade, car chassis, PCB.
   • Additive: 3D print arm, lamp shade, arm base.
   • Subtractive: laser-cut acrylic car chassis; milled PCB.
   • Electronics: design and production of the circuit board.
   • Embedded programming: control program, screen, web interface.
   • System integration and packaging: still finishing shared power so the parts run as one machine.
9. What questions were answered? What the robot is for, what to design, materials and processes, and how to judge success (expression, color, motion, free movement). Still open: how to power the whole robot from one supply; which license to put on the files and the slide.
10. What worked? What didn’t? Worked: Week 9 / 10 boards as final input and output; Week 6 PCB path; arm design and reinforcement. Not finished as a full system: shared power wiring for screen, ESP32-C3, MaixCAM, servo board, and motor board.
11. How was it evaluated? Pass if it recognizes expression and color, answers with movement and a face on the screen, and moves on its own.
12. What are the implications? Intended users are desk workers who want a small reactive companion, plus other Fab Academy students and Fab Lab visitors who may rebuild or adapt a similar machine (Week 18). Longer implications (who this helps after Fab Academy, and what others should take from the files) are still brief / open.

Reference

• Original design files (CAD / PCB): robotic-arm.f3d (Week 2); PCB.f3d (Week 6). Further files are linked from the relevant week pages as they are posted.
• Code: embedded examples and notes on Week 9 (input) and Week 10 (output); interface direction on Week 14.
• Planning / development: Week 17, Week 18; integration pages Week 15, Week 19.
• Presentation assets (site root): presentation.png, presentation.mp4 (drafts — wrong size / resolution until replaced).
• Acknowledgements: chassis idea — sophicar; arm motion — Elephant Robotics; look — Pixar’s Luxo Jr.
• License: Not chosen yet. Which license covers the documentation, CAD, and code (and the notice on the presentation slide) is still open — see Week 18 §1.3.

Final project requirements (checklist)

Secondary checklist of official items covered by the sections above:

• BOM with sources and cost (~¥556) — yes (table above / Week 17).
• Links to contributing weeks — yes (timeline + Reference).
• Summary slide and video in site root — files present; not yet at required 1920×1080 / 1080p.
• Original design files noted / linked — yes (Week 2 arm, Week 6 PCB).
• Acknowledge others’ work — yes (sophicar, Elephant Robotics, Luxo Jr.).
• License — TBD.
• System integration / shared power — not done.