Laser Harp Musical Instrument

Ready-to-play laser harp instrument with automatic startup

🎵 What is a Laser Harp?

A laser harp is an electronic musical instrument that uses laser beams as "strings." When you move your hand through a laser beam, it triggers a musical note. This creates a futuristic, touch-free playing experience similar to playing an invisible harp in the air.

This instrument is pre-configured and ready to use - simply power it on and start playing!

⚡ Quick Start (Normal Operation)

Power On & Play

1. Connect speakers/headphones to the Raspberry Pi audio output
2. Power on the Raspberry Pi - the system will auto-start (takes 30-60 seconds)
3. Wait for startup - you'll hear the system initialize
4. Start playing - move your hands through the laser beams to create music!

Playing the Instrument

• 13 laser beams create different musical notes
• Left side = higher pitched notes (E6)
• Right side = lower pitched notes (C4)
• Multiple beams can be triggered simultaneously for chords
• Smooth movements create better musical expression

🎹 Note Layout

The laser beams are arranged from left to right as follows:

E6 - D6 - C6 - A5 - G5 - E5 - D5 - C5 - A4 - G4 - E4 - D4 - C4
(High)                                                      (Low)

🎮 How to Play

1. Power On: Ensure both Pi and Pico are running
2. Check Lasers: All laser beams should be visible and hitting their sensors
3. Test: Move your hand through a laser beam - you should hear a note
4. Play Music:
   • Move hands through beams to trigger notes
   • Multiple beams can be broken simultaneously for chords
   • The leftmost laser (GP0) plays the highest note (E6)
   • The rightmost laser (GP20) plays the lowest note (C4)

🔧 Troubleshooting

No Sound

• Check FluidSynth is running: ps aux | grep fluidsynth
• Verify MIDI connections: aconnect -l
• Check audio output settings on Pi

False Triggers

• Adjust DEBOUNCE_MS value in final_code.py (try 10-50ms)
• Check for ambient light interference
• Ensure sensors are properly aligned with lasers

Notes Stuck On

• This was fixed in final_code.py - make sure you're using the debounced version
• Restart the Pico if issues persist

MIDI Connection Issues

• Unplug and reconnect the Pico USB cable
• Check aconnect -l for new port numbers
• Re-run the aconnect command with correct ports

📁 File Overview

• final_code.py - Main Pico program (recommended version)
• code(No debounce).py - Original version (may have stuck note issues)
• cmds_4_fluidsynth.txt - FluidSynth setup commands and system service info

⚙️ Customization

Change Notes

Edit the notes array in final_code.py to use different musical notes:

NoteTrigger(board.GP0, "C5"),  # Change "E6" to "C5"

Adjust Sensitivity

Modify the debounce time:

DEBOUNCE_MS = 30  # Increase for less sensitivity, decrease for more
## 🔧 Troubleshooting

**The instrument should work automatically after power-on. If you experience issues:**

### No Sound After Startup
1. **Check speakers/headphones** are connected and volume is up
2. **Wait longer** - full startup can take up to 2 minutes
3. **Check system status**:
   ```bash
   # Open terminal and check if FluidSynth is running
   ps aux | grep fluidsynth

4. Manual restart if needed:

   sudo systemctl restart laser-harp-startup.service

Lasers Not Triggering Notes

1. Check laser alignment - ensure beams hit sensors properly
2. Test individual beams - wave hand through each beam slowly
3. Check Pico connection - USB cable should be secure
4. Restart if needed:

   # Check MIDI connections
   aconnect -l
   # Should show both Pico and FLUID Synth

False Triggers (Notes playing randomly)

• Reduce ambient light - bright lights can interfere with sensors
• Check for vibrations - ensure setup is stable
• Clean sensor lenses - dust can cause false readings

System Won't Start Automatically

1. Check power supply - ensure Pi gets clean power
2. Check auto-start service:

   # Check service status
   sudo systemctl status laser-harp-startup.service
   
   # View startup logs
   sudo journalctl -u laser-harp-startup.service -e

3. Manual startup as backup:

   /home/pi/startup.sh

Emergency Reset

If nothing works:

# Kill all processes and restart
sudo pkill fluidsynth
sudo systemctl restart laser-harp-startup.service

🔄 System Information

How the Auto-Start Works

• Boot sequence: Pi powers on → waits 10 seconds → starts FluidSynth → waits for Pico → connects MIDI → ready to play
• Log location: Check /home/pi/fluidsynth.log for system messages
• Service control: Use sudo systemctl [start|stop|restart] laser-harp-startup.service

Maintenance

• Keep clean: Dust sensors and laser lenses regularly
• Stable power: Use quality power supplies for best performance
• Updates: System is self-contained - no regular updates needed

🎯 Performance Tips

• Best lighting: Dimly lit room with minimal ambient light
• Smooth movements: Deliberate, flowing gestures work best
• Hand positioning: Perpendicular cuts through beams trigger cleanest notes
• Multiple notes: Break several beams simultaneously for chords
• Practice: Start with simple melodies, build up to complex pieces---

The instrument is ready to play - just power on and make music with light! 🎶✨

For technical details, see the other documentation files in this folder.