If you like this project, don’t forget to boost it — it really helps support my work.
Boosts are appreciated ❤️
I’m working on this project alone and dedicating my free time to it, so please be understanding. So far, I’ve only received constructive feedback and discussions — thank you all 🙂
Update – May , 2026
Added time zone support
Automatic update detection
Added a small tilt module on GPIO1 — shake the Yeti and it will get angry.
Le piezo buzzer, le module vibreur et le capteur tilt sont des ajouts facultatifs qui apportent plus d’interactions et de personnalité à votre compagnon. Vous pouvez déjà le construire et l’utiliser uniquement avec l’ESP32-C3, l’écran et le capteur tactile capacitif.
Update – March , 2026
Implemented in the stable version
1.3" Oled screen profile added
Compatibility with 0.96" and 1.3" displays in the same code
Redesign of the Yeti control interface
Added a settings page
firmware: V0.3-2003UI
Website redesign.
Added two new expressions. (Angry & fire eyes (animated))
Addition of a text display system
You can now disable unwanted slides in the “Info” section.
Play the Dino game directly with your computer mouse while the game runs on the Yeti’s face.
Trigger the vibration motor (short vibration).
Sound beep.
A piezo buzzer can be added to GPIO5 on the ESP32-C3.
Double-tap simulation.
Long-tap simulation.
Select which emotion is displayed.
Child mode fully implemented.
Dino Jump–style game to the information panel
Big thanks to Lepczynski - Tech, Cloud & AIfor this amazing video! Please support him by following his channel, liking the video and sharing it!”
You may also notice a version for a 1.3" display, which works exactly like the 0.96" version, but with a larger screen.
A dedicated 3D project is of course in progress and will be released very soon 🙂
Update — January 08, 2025
ChildMode → emotional Mode
When Child Mode is enabled, the double tap no longer opens the INFO screen.
If Child Mode is enabled while in face mode: the double tap is disabled.
If Child Mode is enabled while in INFO mode: a double tap will exit the INFO screen, and it will no longer be possible to enter it again.
Of course, this mode can be enabled or disabled at any time via yeti.local.
A vibration motor module can now be added to GPIO10. https://leroyd.com/ When in face mode, a long press to display the “love” expression will also activate the vibration, causing the companion to vibrate.
Update — December 29, 2025 - 100% solder-free - Done!
A new solderless printing profile has been added. This profile requires a small ESP32-C3 expansion board. The wiring remains unchanged and can now be done using quick-connect Dupont cables. This board simply adds multiple GND and 3.3V connections. You can find the AliExpress link on leroyd.com in the hardware list.
Update — December 27, 2025
The hardware list (AliExpress links) is now available on the web installer page — leroyd.com.
Added the india time zone (UTC+5:30) to the simple presets for easier configuration. Thanks to sunnymishra for the suggestion 🙂
Added the time zone (UTC+8) to the simple presets for easier configuration. Thanks to user_1788609181 for the suggestion 🙂
Update — December 19, 2025
I redesigned the internal layout of the Yeti to maximize usable space. The ESP32-C3 has been shifted to the left (rear view), freeing up the central volume and improving internal clearance.
The main body remains unchanged. Only the rear panel needs to be reprinted, to properly align the USB port with the new ESP32-C3 position.
This new layout allows:
better cable management
more room for a battery or additional modules
a cleaner and more accessible assembly
Update — Dino Jump-Style game
Dino Jump–style game to the information panel
YETI — Expressive Interactive Robot (ESP32-C3)
YETI is a small expressive interactive robot designed as a living desk object, not just a gadget. It displays animated expressions, reacts to touch, and works as a weather station and connected clock — all without writing a single line of code.
The project is intentionally:
easy to assemble
beginner-friendly
expandable for advanced makers
✨ Key Features
Multiple animated expressions
Capacitive touch interaction
Automatic sleep mode when idle
Built-in weather station (Open-Meteo)
Clock with adjustable time zone
Local web interface
No-code firmware installation & setup
Based on ESP32-C3 Super Mini
🧱 3D Printing & Mechanical Design
The enclosure is designed for:
clean internal integration
progressive, logical assembly
stress-free cable routing
Optional magnet mounting
Each foot includes a slot for an 8 × 2 mm neodymium magnet, allowing:
attachment to metal surfaces
better stability on a base
👉 Completely optional.
🔌 Required Hardware
The hardware list (AliExpress links) is now available on the web installer page — leroyd.com.
ESP32-C3 Super Mini (required)
0.96" OLED display (I²C)
Capacitive touch sensor (TTP223 or compatible)
Dupont wires
Oled : Width: 26.00 mm (~1.024 in) - Height: 26.07 mm (~1.027 in)
From KORNect (thanks to him): Note regarding the TTP223 touch sensor: on his setup, it did not work when connected to GPIO 7, but worked correctly when connected to GPIO 5. This information is shared in case other users encounter similar behavior.
The sensor fits into a dedicated 18 × 16 mm slot (≈ 0.71 × 0.63 inch) 👉 The module must not exceed this size.
Touch sensor assembly
Insert the touch sensor into its slot, with the pins facing toward the inside of the Yeti.
Place the cover and press it firmly into position.
Replace 55.123, 55.123 in the left column with your own GPS coordinates (latitude and longitude).
Select your time zone in the right column.
Click “Save” to apply the changes.
This will update the current outdoor temperature and the local time displayed on your Yeti.
Note: An English version of this configuration page will be available soon.
From this page you can:
adjust time settings
update location
check network status
👉 Everything runs locally, no cloud, no account.
Offline Mode
If you skip the Wi-Fi connection step, the C309 will automatically and immediately switch to offline mode.
In offline mode, you have access to face mode:
Faces change automatically every 2 minutes
Single tap: instantly switch to the next face
Long tap (+3 seconds): display the “love” emote, then return to the happy face
Information Mode (double tap)
Information mode contains 3 screens:
Firmware Displays the installed firmware version and information
Connectivity status Wi-Fi / offline status
Wi-Fi connection On this screen, perform a long tap (+3 seconds) to make the C309 access point appear again in your network list. Connect to it to configure your Wi-Fi network.
🔮 Expandability
A dedicated slot is provided for a micro vibration motor:
Leroyd
