Birthday Bot

This is a tabletop device built on an ESP32-C3 Super mini featuring an animated OLED display, personalized birthday messages from family members, touch interface, and a custom 3D-printed enclosure.

This is a gift to my mom.

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Demo Video (redirect to youtube)

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Features

• Animated OLED gifs — idle blinking, expressions (smirk, yawn, snooze, laser, kiss), and a boot intro sequence, all driven by bitmap frame arrays
• Birthday message mode — cycles through 7 personalized audio recordings, one per family member, with a pulsing heart and sender name on screen
• Capacitive touch input — single tap triggers animations or advances messages; double tap switches between the two system modes
• DFPlayer Mini audio — plays MP3s from a microSD card with per-message volume control
• 3D-printed enclosure — custom housing designed to fit the perfboard assembly

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How It Works

The device runs two top-level modes, switchable at any time with a double tap.

GIF animations mode (default)

The OLED displays an idle blinking face. After a timeout it cycles through a sequence of animated GIF-style expressions stored as bitmap frame arrays. A single tap triggers a kiss animation with a chime sound.

Birthday mode

A lovely greeting filled with hearts with a text box telling the user to tap. Each tap plays an audio message from a different family member while showing their name and a pulsing heart. After the track ends, a pixel-art birthday cake appears with a typewriter prompt to continue. Messages loops through all family members.

Touch logic

Single tap and double tap are distinguished using a deferred detection window (350 ms). This avoids false double-tap triggers while keeping response feel snappy.

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State Diagram

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Hardware

Component	Details
Microcontroller	ESP32-C3 Super Mini
Display	0.96" I2C OLED Display
Audio module	DFPlayer Mini
Touch sensor	TTP223 Capacitive Touch Switch
Storage	16GB TF from facebook marketplace
Enclosure	Custom 3D-printed PLA housing

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Wiring

ESP32 Pin	Connected To
GPIO 8 (SDA)	OLED SDA
GPIO 9 (SCL)	OLED SCL
GPIO 1 (TX)	DFPlayer RX
GPIO 2 (RX)	100 ohm resistor + DFPlayer TX
GPIO 10	TTP223 touch output
3.3V / GND	All modules

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SD Card Setup

The DFPlayer Mini reads MP3s by folder and track number, so the card is structured like this:

/mp3/
  0001.mp3   → boot jingle
  0002.mp3   → kiss sound / eye mode ambient
  0003.mp3   → birthday mode entry sound
  0004.mp3   → message from Family member 1
  0005.mp3   → message from Family member 2
  0006.mp3   → message from Family member 3
  0007.mp3   → message from Family member 4
  0008.mp3   → message from Family member 5
  0009.mp3   → message from Family member 6
  0010.mp3   → message from Family Pet

3D-Printed Enclosure

STL files are in /hardware/housing.stl Printed in PLA at 0.1mm layer height. Designed in Autodesk Fusion.

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Acknowledgements

The OLED eye animation framework is based on esp32_dasai_mochi_clone_and_how_to by huykhoong, which provided the bitmap frame rendering approach for the SSD1306 display.

My additions:

• DFPlayer Mini audio module integration with per-message volume control
• TTP223 capacitive touch sensor with single/double-tap detection
• Birthday mode with 7 personalized family message tracks
• Dual-mode system architecture with runtime switching
• Custom 3D-printed enclosure

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