An interactive ATtiny85-powered Christmas tree with LED candle effects and breath-controlled music playback.
Get your kit at BlinkyParts.com!
Demo
🎥 Watch the demo video - Shows candle effect, breath detection, and melody playback with LED visualization
Features
- 🕯️ Realistic Candle Effect - Four LED rings flicker independently
- 🎤 Breath Detection - Blow to trigger songs or increase flicker intensity
- 🎵 Music Playback - Built-in buzzer plays Christmas melodies
- 🎨 LED Light Show - LEDs react to note frequencies
- ⚙️ Fully Customizable - Add your own songs via GitHub Actions (no coding required!)
🎵 Customize Your Songs (No Setup Required!)
Customize songs directly on GitHub - no local development environment needed!
- Fork this repository on GitHub
- Edit
config.yamlto enable/disable songs and adjust settings - Add MusicXML files to the
songs/folder (export from MuseScore, Finale, etc.) - Push changes - GitHub Actions automatically builds your firmware
- Download the
.hexfile from Actions → Artifacts - Flash to your BlinkyTree - See FLASHING_GUIDE.md
Song Configuration
Edit config.yaml to customize each song:
songs: JINGLE_BELLS: enabled: true duty_cycle: 80 # Volume (10-100) speed: 150 # Tempo (25-200, 100=original) transpose: 0 # Pitch shift (-12 to +12 semitones)
Adding New Songs
- Export your melody as MusicXML (MuseScore: File → Export → MusicXML)
- ⚠️ Important: In MuseScore, export as Uncompressed MusicXML (not .mxl)
- File extension should be
.musicxml
- Upload the
.musicxmlfile to thesongs/folder - Add an entry in
config.yamlwith the same filename (without extension) - Commit and push - GitHub Actions builds your custom firmware!
Requirements: Single melody line, note range G3-B5, standard durations
Hardware
ATtiny85 Pinout:
┌─────────────┐
RESET│1 • 8 │ VCC (+3-5V)
MIC │2 7 │ LED_1ER
BUZZER│3 6 │ LED_5ER (PWM)
GND │4 5 │ LED_4ER (PWM)
└─────────────┘
Pin Mapping:
Pin 1: PB5 (RESET) - ISP Programming
Pin 2: PB3 (MIC/LED_3ER) - Shared/Time-multiplexed
Pin 3: PB4 (BUZZER)
Pin 5: PB0 (LED_4ER) - Hardware PWM
Pin 6: PB1 (LED_5ER) - Hardware PWM
Pin 7: PB2 (LED_1ER) - Software PWM
Components:
- ATtiny85 microcontroller (8MHz internal)
- 4 LED rings (1, 3, 4, 5 LEDs)
- Electret microphone with peak detector
- Piezo buzzer
- Power: 3-5V (battery or USB)
Quick Start
Option 1: Flash Pre-Built Firmware
- Download the latest firmware from Releases
- Follow the FLASHING_GUIDE.md
- Use the included
flash_firmware.bat(Windows) orflash_firmware.sh(Linux/macOS)
Option 2: Build Locally
Prerequisites:
- PlatformIO Core or VS Code with PlatformIO extension
- Python 3.11+ with PyYAML (
pip install pyyaml)
Build and Upload:
pio run # Build firmware pio run --target upload # Upload to ATtiny85 (requires ISP programmer)
Flashing
Quick Flash
Windows: Double-click flash_firmware.bat
Linux/macOS: Run ./flash_firmware.sh
The scripts auto-detect your ISP programmer and flash automatically.
Manual Flash
# USBasp avrdude -c usbasp -p attiny85 -U flash:w:firmware.hex:i # AVRISPv2 avrdude -c avrisp2 -P usb -p attiny85 -U flash:w:firmware.hex:i
Need help? See the complete FLASHING_GUIDE.md for:
- ISP programmer setup and connections
- Driver installation (Windows)
- Fuse configuration
- Detailed troubleshooting
How It Works
Startup
- Hardware initialization (LEDs, microphone, buzzer)
- Microphone calibration
- Candle effect starts automatically
Operation
Idle: Four LED rings flicker independently with realistic candle simulation
Light Breath: Candle flicker intensity increases proportionally
Strong Breath: Triggers a random song from your enabled playlist
Configuration
Song Settings (config.yaml)
Edit config.yaml to customize songs - this is what most users will need:
songs: JINGLE_BELLS: enabled: true duty_cycle: 80 # Volume/tone (10-100) speed: 150 # Tempo (25-200, 100=original) transpose: 0 # Pitch shift (-12 to +12 semitones)
Hardware Settings (config.yaml)
All hardware behavior can now be customized through config.yaml:
hardware: # LED system led_brightness_default: 30 # Base LED brightness (10-100) candle_flicker_speed: 150 # Candle flicker rate in ms (50-500, lower=faster) candle_flicker_intensity: 70 # Flicker intensity percentage (20-100) # Audio system song_cooldown: 3000 # Time between songs in ms (1000-10000) note_separation: 50 # Gap between notes in ms (0-200) startup_melody: false # Play song at startup (true/false) # Sensor settings breath_sensitivity: 1 # Breath detection threshold (1-50, lower=more sensitive) sensor_update_rate: 5 # Sensor check interval in ms (1-50, lower=more responsive)
These settings are automatically converted to firmware configuration during compilation.
Project Structure
BlinkyTree/
├── config.yaml # Song configuration (edit this!)
├── songs/*.musicxml # MusicXML song files
├── src/main.cpp # Main application
├── lib/
│ ├── Audio/ # Audio system
│ │ ├── audio.h/cpp # Core audio engine
│ │ └── audio_songs_generated.* # Auto-generated from MusicXML
│ ├── Lighting/ # LED effects
│ ├── Hardware/ # GPIO/PWM/ADC abstraction
│ └── Sensors/ # Microphone processing
├── scripts/
│ ├── generate_audio_code.py # MusicXML → C converter
│ └── pre_build.py # Build automation
├── flash_firmware.bat/.sh # Automated flashing scripts
└── FLASHING_GUIDE.md # Detailed flashing instructions
Troubleshooting
LEDs not working:
- Check power supply (3-5V)
- Verify LED polarity
Microphone not responding:
- Adjust
BREATH_STRONG_THRESHOLDinconfig/config.h(lower = more sensitive) - Check microphone circuit connection (Pin 2)
- Verify calibration during startup
Upload fails:
- Verify ISP connections (all 6 pins)
- Check programmer COM port in
platformio.ini
See FLASHING_GUIDE.md for more details.
Default Memory Usage
- Flash: ~5KB / 8KB (60-70%)
- RAM: ~150 bytes / 512 bytes (25-30%)
Resources
- Hardware: BlinkyParts.com Kit
- Flashing Guide: FLASHING_GUIDE.md
- ATtiny85 Datasheet: Microchip
- PlatformIO: docs.platformio.org
License
CC-BY-NC 4.0 - Non-commercial use only
You may share and adapt this project with attribution to monkeyToneCircuits.
See LICENSE for details.
Made with ❤️ by monkeyToneCircuits