Building a Tiny Desktop Toy Pet with Xiao ESP32‑S3 & JUSTWAY

A maker set out to design a playful desktop companion—a miniature “pet” that could sit on a desk, blink, react to touch, and display emotions on a tiny OLED screen. Using the Xiao ESP32‑S3 microcontroller, a 0.9‑inch OLED display and a custom enclosure printed through JUSTWAY’s 3D printing service, the project came to life as a step‑by‑step build that others can replicate.

Project Overview

• Objective: Create a small interactive pet with expressive animations.
• Core Hardware: Xiao ESP32‑S3, 0.9" OLED, Li‑Po battery.
• Enclosure: 3D printed shell designed for compactness and personality.

Materials Used

• Xiao ESP32‑S3 development board
• 0.9" OLED (SSD1306/SH1106 controller)
• Li‑Po battery (300–500 mAh)
• 3D printed case from JUSTWAY
• Basic tools: soldering iron, wires, screws, hot glue

Designing and Printing the Case

• Screen window sized precisely for the OLED.

• Standoffs for mounting the ESP32 board.

• Xiao bay with cable routing.
• USB‑C cutout for charging and programming.

Wiring and Electronics

OLED: Connected via I2C (SDA, SCL, 3.3V, GND).

Firmware and Behavior

The firmware was written in the Arduino IDE using the Adafruit SSD1306 and RoboEyeslibraries.

A simple sketch controlled the OLED graphics.

#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#include <FluxGarage_RoboEyes.h>
// create a RoboEyes instance using an Adafruit_SSD1306 display driver
RoboEyes<Adafruit_SSD1306> roboEyes(display); 


// EVENT TIMER
unsigned long eventTimer; // will save the timestamps
bool event1wasPlayed = 0; // flag variables
bool event2wasPlayed = 0;
bool event3wasPlayed = 0;


void setup() {
  // OLED Display
  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C or 0x3D
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }

  // Startup robo eyes
  roboEyes.begin(SCREEN_WIDTH, SCREEN_HEIGHT, 100); // screen-width, screen-height, max framerate - 60-100fps are good for smooth animations
  roboEyes.setPosition(DEFAULT); // eye position should be middle center
  roboEyes.close(); // start with closed eyes 
  
  eventTimer = millis(); // start event timer from here

} // end of setup


void loop() {
 roboEyes.update(); // update eyes drawings

  // LOOPED ANIMATION SEQUENCE
  // Do once after defined number of milliseconds
  if(millis() >= eventTimer+2000 && event1wasPlayed == 0){
    event1wasPlayed = 1; // flag variable to make sure the event will only be handled once
    roboEyes.open(); // open eyes 
  }
  // Do once after defined number of milliseconds
  if(millis() >= eventTimer+4000 && event2wasPlayed == 0){
    event2wasPlayed = 1; // flag variable to make sure the event will only be handled once
    roboEyes.setMood(HAPPY);
    roboEyes.anim_laugh();
    //roboEyes.anim_confused();
  }
  // Do once after defined number of milliseconds
  if(millis() >= eventTimer+6000 && event3wasPlayed == 0){
    event3wasPlayed = 1; // flag variable to make sure the event will only be handled once
    roboEyes.setMood(TIRED);
    //roboEyes.blink();
  }
  // Do once after defined number of milliseconds, then reset timer and flags to restart the whole animation sequence
  if(millis() >= eventTimer+8000){
    roboEyes.close(); // close eyes again
    roboEyes.setMood(DEFAULT);
    // Reset the timer and the event flags to restart the whole "complex animation loop"
    eventTimer = millis(); // reset timer
    event1wasPlayed = 0; // reset flags
    event2wasPlayed = 0;
    event3wasPlayed = 0;
  }
  // END OF LOOPED ANIMATION SEQUENCE

} // end of main loop

Powered by JUSTWAY 3D Printing Service 🖨️

For the prototype, I partnered with JUSTWAY 3D Printing Service — a reliable platform that brings ideas to life with precision and speed.

How to Order Your 3D Print 🖨️

For this project, I used JUSTWAY 3D Printing Service to bring my gate prototype to life. Ordering your own custom print is simple and beginner‑friendly:

• Create or download a 3D model (e.g.,. STL.STL or .OBJ file).
• Visit the JUSTWAY 3D Printing Service platform.
• Upload your design file directly through their interface.

• Select from options like PLA, ABS, PETG, or specialty filaments.Pick the color and finish that suits your prototype.
• The platform provides a real‑time cost estimate based on size, material, and complexity.

• Confirm your design and checkout securely.
• JUSTWAY handles the printing and ships the finished part to your address.

• You’ll have a professional‑looking prototype ready for demos.

Assembly Process

• Dry fit: Components were placed inside the printed shell.
• OLED mount: The screen was secured behind the faceplate.
• Board installation: Xiao ESP32‑S3 fixed to standoffs.
• Battery placement: Li‑Po taped into its bay.
• Wiring: Neatly routed and secured with hot glue.
• Final closure: Faceplate attached, firmware uploaded, and the pet powered on.

Outcome

The finished desktop pet blinked, chirped, and responded to touch, giving the impression of a tiny creature with personality. The combination of ESP32‑S3’s power, OLED’s expressiveness, and JUSTWAY’s precise 3D printing made the project both technically sound and emotionally engaging.