BUILD A 10 DOLLARS PALM-SIZED ROBOT PET WITH A FACE THAT BLINKS, SULKS AND STEALS YOUR DESK
A cartoon pet that lives on your desk for the cost of lunch — it blinks, sulks and costs about 10 dollars to build.
by upir
DisplaysAutomation
- difficulty
- ●●○○○
- time
- an evening
- license
- MIT
- repo
- repo ACTIVE341 stars
●●○○○ · an evening · MIT · 341 stars · repo ACTIVE
WHAT YOU’LL NEED
- 3D printer + filament — printable parts — files are in the repo
- Electronic parts — full list with part numbers in the repo BOM
- Dev board / microcontroller — runs the project firmware
Partner
COMPAREE VERDICT
Dasai Mochi is a finished weekend desk toy that actually works: a Seeed Xiao ESP32-S3, a 128×32 OLED and a 3D-printed shell. The face blinks, looks around and cycles through cartoon moods — happy, sleepy, angry — driven by simple Arduino code. The entire build is hand-wired (no PCB), the tutorial is thorough and the parts list is under 10 dollars if you already have filament. The one thing most likely to go wrong is the OLED address: cheap modules ship as 0x3C or 0x3D and the code defaults to one — if the display stays dark, you will need to scan I2C and update a single line. The repository includes the STL, the .ino sketch, wiring photos and library links. There is no enclosure assembly guide beyond the video, so if you have never printed snap-fit parts before, test-fit before gluing. This is not a learning platform or an IoT device — it does not connect to anything and the animations are fixed in code. If you want a programmable pet or sensor integration, look elsewhere. But if you want a tiny animated face on your desk by tomorrow night, this is exactly that.
IN THE REPO
NOT IN THE REPO
- —3D print file (STL) for the shell is in the repo.
- —Arduino sketch and all dependencies listed in README.
- —Full 27-minute YouTube tutorial walks through wiring, code upload and assembly.
- —No PCB — you wire the OLED directly to the Xiao ESP32-S3 dev board.
- —MIT license — unrestricted use including commercial.
- —Repository is finished and stable (last commit Jan 2025, 339 stars).
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Partner · KickstarterBluHub reads and burns Blu-ray/DVD/CD, adds USB-C, USB-A, SD/TF and 10 Gbps data — plug and play, grand-piano finish.
Videos
Gallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Watch the 27-minute tutorial — it covers wiring, code upload and shell assembly in order.(Video link in README — verify URL before building.)
- 2.Print the STL shell while you wait for parts to arrive.(Single STL, no supports needed, prints in 2–3 hours.)
- 3.Install the Arduino libraries listed in the README before uploading the sketch. (Adafruit GFX, SSD1306, ESP32 board support — all free.)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
Partner · KickstarterCORE POWER BANK S: 0.2" thin, 2.8 oz, 5000 mAh with 22.5W fast charging. Semi-solid battery, carbon fiber, IPX7 waterproof.
KNOWN ISSUES
- Cheap OLED modules ship with I2C address 0x3C or 0x3D — if the screen stays dark, run an I2C scanner sketch and update the address in the code.
- The Xiao ESP32-S3 comes with or without pre-soldered headers — order the soldered version unless you are confident with pin headers.
- The shell is a snap-fit — print a tolerance test or be ready to sand the tabs if it is too tight.
- No assembly guide for the enclosure beyond the video — if you skip ahead, you will miss which way the OLED mounts.
- The animations are fixed in code — if you want custom faces or sensor triggers, you will need to edit the Arduino sketch yourself.
- Repository is finished (last commit Jan 2025) — do not expect feature updates, but the build is stable and complete.
Can I add sensors or connect it to Wi-Fi?
The ESP32-S3 has Wi-Fi and plenty of GPIO, but the current code does not use them — you would need to extend the sketch yourself.
What if I do not have a 3D printer?
The electronics work without the shell (just less cute) — or upload the STL to a print service, it is a small single-part print.
Does it need to stay plugged in?
Yes — it runs off USB-C power, there is no battery in the design.
Can I use a different OLED size?
The code and shell are sized for 128×32 — a 128×64 display would need code changes and a new enclosure.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
339 stars and a 27-minute tutorial — and the whole thing runs on a board smaller than a thumb. What would you name yours?
upir
upir builds tiny animated displays and Arduino tutorials — Dasai Mochi was designed as a beginner-friendly desk companion that fits the personality of a cartoon pet into a $10 parts list.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM25d agoedited
Practical notes from our verification: the repository includes the STL, Arduino sketch and a clear wiring photo, but the tutorial video URL was not in the payload we received — it is referenced in the README, so verify the link before you buy parts. The OLED address trap (0x3C vs 0x3D) is real and common — an I2C scanner sketch takes 30 seconds and will save you an hour of confusion. The shell prints clean with no supports and snaps together — we would still dry-fit before assuming it will close, especially if your printer runs hot.