⚡ Constellations - Electronics Build Guide

Difficulty Level: Moderate (requires Arduino/electronics experience)

Build Time: 6-8 hours (wiring + programming + testing)

Cost: $160-$200 for all electronics

1. Components & Materials

Required Electronics

Component	Quantity	Specifications	Est. Cost	Source
Arduino Mega 2560	1	54 digital pins, 16 analog inputs	$35-45	Amazon, Adafruit
WS2812B LED Strip	3-4 meters	60 LEDs/meter, addressable RGB, 5V	$30-50	Amazon, AliExpress
Arcade Buttons (Illuminated)	8	30mm push buttons with LED indicators	$25-35	Amazon, Adafruit
5V Power Supply	1	5V 10A (50W minimum), barrel jack output	$20-30	Amazon
3-Position Rotary Switch	1	For difficulty selector (Easy/Med/Hard)	$5-8	Amazon, Mouser
Push Buttons (non-illuminated)	3	For New Puzzle, Check, Reset	$5-10	Amazon
Resistors	1 pack	220Ω and 10kΩ assortment	$8	Amazon
22 AWG Wire	50 feet	Various colors (red, black, green, etc.)	$15	Amazon
Breadboard/Protoboard	1	For organizing connections	$10	Amazon
Connectors & Headers	Assorted	JST connectors, screw terminals	$10-15	Amazon
Project Enclosure	1	For Arduino and wiring (optional)	$15-20	Amazon

Total Estimated Cost: $178-236

Why Arduino Mega? The Mega has 54 digital I/O pins, which is essential for handling 8 button inputs + 3 control buttons + rotary switch + LED strip control. The standard Arduino Uno only has 14 digital pins, which isn't enough.

2. Wiring Diagram

Arduino Mega Pin Connections

🔴 Power Connections

5V Power Supply (+) → LED Strip (+5V)
5V Power Supply (+) → Arduino VIN
5V Power Supply (GND) → Common Ground
Arduino GND → Common Ground
LED Strip GND → Common Ground

💡 LED Strip

Data In (DIN) → Arduino Pin 6
+5V → Power Supply (+5V)
GND → Common Ground

🎮 Toggle Buttons (1-8)

Button 1 → Pin 22
Button 2 → Pin 24
Button 3 → Pin 26
Button 4 → Pin 28
Button 5 → Pin 30
Button 6 → Pin 32
Button 7 → Pin 34
Button 8 → Pin 36
All buttons use internal pullup resistors

🕹️ Control Buttons

New Puzzle → Pin 38
Check Answer → Pin 40
Reset → Pin 42
All use internal pullup resistors

⚙️ Difficulty Selector

Common → GND
Easy → Pin 44
Medium → Pin 46
Hard → Pin 48

💡 Button LED Indicators

Button 1 LED → Pin 23
Button 2 LED → Pin 25
Button 3 LED → Pin 27
Button 4 LED → Pin 29
Button 5 LED → Pin 31
Button 6 LED → Pin 33
Button 7 LED → Pin 35
Button 8 LED → Pin 37
Add 220Ω resistor inline with each LED

                    5V 10A Power Supply
                     +5V          GND
                      |            |
         +------------+------------+------------+
         |            |            |            |
         |         Arduino       LED Strip    Common
         |          VIN          +5V/GND      Ground
         |            |                         |
         |         Arduino                      |
         |          GND -------------------------+
         |                                      |
    LED Strip                              All Button
    Data → Pin 6                           GND connections


Button Connections (with internal pullup):

    Toggle Buttons:      Control Buttons:      Difficulty Switch:
    Button 1 → Pin 22    New → Pin 38          Easy → Pin 44
    Button 2 → Pin 24    Check → Pin 40        Med → Pin 46
    Button 3 → Pin 26    Reset → Pin 42        Hard → Pin 48
    Button 4 → Pin 28
    Button 5 → Pin 30    Each button connects between
    Button 6 → Pin 32    pin and GND (pulled HIGH when
    Button 7 → Pin 34    not pressed, LOW when pressed)
    Button 8 → Pin 36

Button LED Indicators (220Ω resistors required):

    Button 1 LED → 220Ω → Pin 23 → GND
    Button 2 LED → 220Ω → Pin 25 → GND
    Button 3 LED → 220Ω → Pin 27 → GND
    ... (continue for all 8 buttons)

⚠️ IMPORTANT POWER NOTES:

LEDs draw significant current (~3-5A with 200 LEDs). DO NOT power LEDs from Arduino's 5V pin
Use dedicated 5V power supply rated for at least 10A
Connect Arduino VIN to same 5V supply (shares power, separate circuits)
Ensure common ground between Arduino, LEDs, and power supply
Add 1000µF capacitor across LED strip power terminals to prevent voltage spikes

3. Assembly Steps

Step 1: Prepare the Panel

Cut/route constellation outlines into 4'×6' panel
Drill button mounting holes (30mm) at bottom of panel
Route shallow channels for LED strips along constellation branches
Paint panel matte black for best contrast

Step 2: Install LED Strips

Measure and cut WS2812B strip into segments for each constellation branch
Secure strips in routed channels with adhesive backing
Solder data connections between segments (DIN → DOUT chain)
Test each segment with Arduino before permanent mounting
Use hot glue or silicone to secure solder joints

LED Strip Tip: Number each constellation and segment as you wire them. This makes programming much easier! Example: Constellation A, Segment 1 = LED indices 0-5, Segment 2 = 6-11, etc.

Step 3: Wire Buttons

Mount 8 illuminated arcade buttons in drilled holes
Run wires from each button to Arduino (see pin diagram)
Wire button LEDs through 220Ω resistors to Arduino output pins
Mount control buttons (New/Check/Reset) on separate control panel or side of main panel
Label each button clearly

Step 4: Power Supply Setup

Mount 5V power supply in enclosure or behind panel
Connect +5V to LED strip positive
Connect +5V to Arduino VIN
Connect GND to common ground bus
Add 1000µF capacitor across LED power terminals
Test voltage with multimeter before powering Arduino

Step 5: Arduino Installation

Mount Arduino Mega in project enclosure
Connect all button inputs to assigned pins
Connect LED strip data pin to Pin 6
Connect power (VIN + GND)
Secure all wiring with zip ties and cable management

🔧 Testing Protocol: Test each component individually before final assembly!

Test buttons with Arduino (digitalRead test sketch)
Test LED strips (FastLED test sketch with all LEDs white)
Test button indicators (digitalWrite test)
Only after all components work individually, upload full game code

4. Arduino Software Setup

Required Libraries

// Install these libraries via Arduino Library Manager:

FastLED         // For controlling WS2812B LED strips
Bounce2         // For button debouncing (optional but recommended)

Library Installation

Open Arduino IDE
Go to Sketch → Include Library → Manage Libraries
Search for "FastLED" and click Install
Search for "Bounce2" and click Install
Restart Arduino IDE

✅ Arduino Sketch Ready: The complete Arduino code is provided in the file constellation_led_wall.ino in this directory. Upload it to your Arduino Mega after wiring is complete.

5. Testing & Calibration

Initial Power-On Test

Power on system with USB connected to computer (Serial Monitor open)
Verify Arduino boots successfully (check Serial output)
Check that all 200 LEDs light up in startup sequence
Press each toggle button - verify LED indicator lights up
Test control buttons (New/Check/Reset) via Serial Monitor output

LED Mapping Verification

Use test mode in Arduino sketch (uncomment TEST_MODE define)
Verify each button lights up correct constellation segments
Adjust LED index mappings in code if segments don't match expected
Document actual LED index ranges for each constellation segment

Puzzle Testing

Test Easy mode - verify 2-3 targets can be solved
Test Medium mode - verify increased difficulty
Test Hard mode - verify complex overlapping patterns
Test Check Answer feedback - success/partial/fail indicators
Test Reset and New Puzzle buttons

6. Troubleshooting Common Issues

LEDs Not Lighting

Check power supply: Verify 5V at LED strip terminals
Check data connection: DIN pin properly connected to Pin 6?
Check common ground: Arduino GND connected to LED strip GND?
Check LED count: Is NUM_LEDS defined correctly in code?

Buttons Not Responding

Check wiring: Button connected between pin and GND?
Check pullup mode: Code uses INPUT_PULLUP for all buttons
Check pin assignments: Verify pins match code defines
Serial debug: Use Serial.println() to verify button reads

Wrong Segments Lighting Up

LED index mapping error: Verify segment-to-LED-index mapping in code
Data signal issue: Check solder joints on LED strip data connections
Test mode: Use TEST_MODE to identify which physical LEDs correspond to each index

Arduino Crashes/Resets

Power supply insufficient: Upgrade to higher amperage supply
Voltage drop: Add capacitors across LED power terminals
Memory overflow: Check available RAM (should have 4KB+ free on Mega)

7. Final Assembly Notes

Best Practices:

Use heat shrink tubing on all solder joints
Label all wires at both ends (masking tape + sharpie)
Take photos during assembly for documentation
Test frequently - don't wait until everything is assembled
Keep Arduino accessible for code updates/debugging
Add strain relief for all cable connections

Estimated Build Time Breakdown:

Panel preparation: 2-3 hours
LED strip installation: 3-4 hours
Button wiring: 2 hours
Power supply setup: 1 hour
Arduino programming: 2-3 hours
Testing & debugging: 2-4 hours
Total: 12-17 hours