# Quick Flash Guide - D1 Mini Blinkin Emulator

## What You'll Build
A $7 replacement for the $35 REV Blinkin LED Driver that works identically with FTC code!

## Parts List
- **D1 Mini** (ESP8266) - $4
- **2.2kΩ resistor** - $0.10
- **3.3kΩ resistor** - $0.10
- **Servo extension cable** - $2
- **WS2812B LED strip** (30-60 LEDs) - $10-15
- **Soldering supplies**

## Step 1: Build the Voltage Divider

### Why It's Needed
- Servo port outputs 5V signals
- D1 Mini only handles 3.3V
- Without this, you'll fry your D1 Mini!

### Quick Assembly
1. Cut servo cable 6" from female connector
2. Strip wires (Red=5V, Black=GND, White=PWM)
3. Solder resistors like this:
```
White wire ──[2.2kΩ]──┬── Wire to D2
                       │
                    [3.3kΩ]
                       │
                    Black wire
```
4. Heat shrink everything

## Step 2: Flash the D1 Mini

### Install Arduino IDE
1. Download from [arduino.cc](https://www.arduino.cc/en/software)
2. Open Arduino IDE
3. File → Preferences → Additional Board URLs:
   ```
   http://arduino.esp8266.com/stable/package_esp8266com_index.json
   ```
4. Tools → Board → Board Manager → Search "ESP8266" → Install

### Install Library
Tools → Manage Libraries → Search "Adafruit NeoPixel" → Install

### Flash the Code
1. Open `D1Mini_Blinkin_Ready.ino`
2. **IMPORTANT: Edit line 20-21 for your setup:**
   ```cpp
   #define NUM_LEDS 60        // Change to your LED count
   #define BRIGHTNESS 100     // Adjust brightness (0-255)
   ```
3. Tools → Board → "LOLIN(WEMOS) D1 R2 & mini"
4. Tools → Port → Select your COM port
5. Click Upload (→ button)

## Step 3: Wire Everything

### Final Connections
```
Servo Port          D1 Mini            LED Strip
==========          =======            =========
Red ───────────────→ 5V
Black ─────────────→ GND ─────────────→ GND
White ─→[Divider]──→ D2
                     D4 ───────────────→ Data In
                                        5V ← External Power
```

### Power Notes
- < 30 LEDs: Can use servo port power
- > 30 LEDs: Need external 5V supply for LEDs

## Step 4: Test It

### With Serial Monitor
1. Open Tools → Serial Monitor
2. Set to 115200 baud
3. You should see:
   ```
   D1 Mini Blinkin Emulator v2.0
   Kraken Koders FTC Team
   Ready for PWM signal...
   ```

### With FTC Robot
1. Configure as servo in robot config
2. Name it "blinkin"
3. Use this test code:
```java
RevBlinkinLedDriver blinkin = hardwareMap.get(RevBlinkinLedDriver.class, "blinkin");
blinkin.setPattern(RevBlinkinLedDriver.BlinkinPattern.RAINBOW_RAINBOW_PALETTE);
```

## Troubleshooting

### LEDs Don't Light
- Check D4 → LED data connection
- Verify LED strip arrow points away from D1 Mini
- Test with simple color first

### No PWM Reading
- Measure voltage divider output (should be ~3V)
- Check servo port is powered
- Verify resistor values

### Wrong Colors
- Some strips are RGB instead of GRB
- Change line in code:
  ```cpp
  // Change from:
  Adafruit_NeoPixel strip(NUM_LEDS, LED_DATA_PIN, NEO_GRB + NEO_KHZ800);
  // To:
  Adafruit_NeoPixel strip(NUM_LEDS, LED_DATA_PIN, NEO_RGB + NEO_KHZ800);
  ```

### D1 Mini Keeps Resetting
- Too many LEDs for power supply
- Reduce brightness or LED count
- Add external 5V power

## Quick Test Without Robot

Use a servo tester or Arduino to generate PWM:
```cpp
// Arduino test signal generator
void setup() {
  pinMode(9, OUTPUT);
}
void loop() {
  // Sweep through patterns
  for(int pw = 1000; pw <= 2000; pw += 10) {
    digitalWrite(9, HIGH);
    delayMicroseconds(pw);
    digitalWrite(9, LOW);
    delay(20);
  }
}
```

## Pattern Reference

| PWM (μs) | Pattern |
|----------|---------|
| 1005-1015 | Rainbow |
| 1065 | Confetti |
| 1315 | Breath Red |
| 1325 | Breath Blue |
| 1515 | Solid Red |
| 1645 | Solid Blue |
| 1595 | Solid Green |
| 1675 | Solid White |
| 1995 | Off |

## Success Checklist

- [ ] Voltage divider outputs 3V (measured)
- [ ] D1 Mini powers on
- [ ] Serial monitor shows "Ready"
- [ ] Green sweep on startup
- [ ] Responds to PWM changes
- [ ] Works with FTC code

## Total Cost
- D1 Mini: $4
- Resistors: $0.20
- Cable: $2
- **Total: $6.20** (vs $35 for REV Blinkin)

## Need Help?
- Check serial monitor for debug info
- Onboard LED blinks = receiving PWM
- Green startup = code running
- No response = check voltage divider

**You now have a fully functional Blinkin emulator for 1/5 the price!**