D1 Mini Blinkin LED Driver Emulator

This project allows a D1 Mini (ESP8266) to emulate a REV Blinkin LED Driver, enabling control of WS2812B LED strips via PWM signals from an FTC robot's REV Control Hub or Expansion Hub.

Features

• Full Blinkin Pattern Support: Emulates 100+ Blinkin patterns including solid colors, animations, and effects
• PWM Signal Input: Reads standard servo PWM signals (900-2100 microseconds)
• 60 LED Support: Configured for 60 WS2812B LEDs (adjustable in code)
• FastLED Library: High-performance LED control with color correction
• Debug Mode: Serial output for troubleshooting PWM values and patterns
• No WiFi: WiFi disabled to save power and improve performance

Hardware Requirements

• D1 Mini (ESP8266) or compatible board
• WS2812B LED strip (60 LEDs default, adjustable)
• Voltage divider circuit (5V to 3.3V for PWM input)
• 5V power supply capable of 3-4A for 60 LEDs
• REV Control Hub or Expansion Hub

Wiring Connections

PWM Signal Input (from REV Hub Servo Port)

IMPORTANT: The REV Hub outputs 5V PWM signals. The D1 Mini requires 3.3V input. You MUST use a voltage divider!

REV Hub Servo Port | Voltage Divider | D1 Mini
-------------------|-----------------|----------
Signal (White)     | Input → Output  | D2 (GPIO4)
Power (Red)        | -               | 5V
Ground (Black)     | -               | GND

Voltage Divider Circuit

REV PWM Signal (5V) ──┬── R1 (2.2kΩ) ──┬── To D1 Mini D2
                      │                 │
                      │                 R2 (3.3kΩ)
                      │                 │
                     GND ───────────────┴── GND

LED Strip Connection

D1 Mini Pin  | LED Strip    | Description
-------------|--------------|-------------
D4 (GPIO2)   | Data In      | LED data signal
5V           | 5V           | Power (use external supply)
GND          | GND          | Ground

Power Note: For 60 LEDs at full brightness, current draw can reach 3.6A. Use an external 5V power supply, not the REV Hub's servo power.

Software Setup

Method 1: PlatformIO (Recommended)

1. Install Visual Studio Code
2. Install PlatformIO IDE extension
3. Clone this repository
4. Open project folder in VS Code
5. Connect D1 Mini via USB
6. Click PlatformIO: Upload (→) in the bottom toolbar

Method 2: Arduino IDE

1. Install Arduino IDE
2. Add ESP8266 Board Support:
   • File → Preferences → Additional Board Manager URLs:
   • Add: http://arduino.esp8266.com/stable/package_esp8266com_index.json
   • Tools → Board → Board Manager → Search "ESP8266" → Install
3. Install FastLED Library:
   • Tools → Manage Libraries → Search "FastLED" → Install
4. Select Board: Tools → Board → "LOLIN(WEMOS) D1 R2 & mini"
5. Open src/main.cpp and upload

FTC Robot Configuration

Hardware Configuration

1. Connect the voltage divider output to a servo port on the REV Hub
2. In the Robot Controller app, configure the servo in your hardware map
3. Name it something meaningful like "blinkin" or "ledDriver"

Example FTC Java Code

import com.qualcomm.robotcore.hardware.Servo;
import com.qualcomm.robotcore.eventloop.opmode.LinearOpMode;

public class BlinkinExample extends LinearOpMode {
    private Servo blinkin;
    
    @Override
    public void runOpMode() {
        // Initialize
        blinkin = hardwareMap.get(Servo.class, "blinkin");
        
        // Set to solid red (pattern value from Blinkin manual)
        blinkin.setPosition(0.61);  // Solid Red
        
        waitForStart();
        
        while (opModeIsActive()) {
            // Alliance color selection
            if (gamepad1.x) {
                blinkin.setPosition(0.87);  // Solid Blue
            } else if (gamepad1.b) {
                blinkin.setPosition(0.61);  // Solid Red
            } else if (gamepad1.a) {
                blinkin.setPosition(0.77);  // Solid Green
            } else if (gamepad1.y) {
                blinkin.setPosition(0.93);  // Solid White
            }
            
            // Special effects
            if (gamepad1.left_bumper) {
                blinkin.setPosition(0.41);  // Rainbow
            }
            if (gamepad1.right_bumper) {
                blinkin.setPosition(0.43);  // Confetti
            }
        }
    }
}

Common Blinkin Pattern Values

Pattern	Servo Position	PWM (μs)	Description
Rainbow	0.41	1005	Rainbow palette
Confetti	0.43	1015	Random colored pixels
Red Shot	0.53	1065	Red chase pattern
Blue Shot	0.54	1075	Blue chase pattern
Red	0.61	1505	Solid red
Orange	0.65	1535	Solid orange
Yellow	0.69	1555	Solid yellow
Green	0.77	1595	Solid green
Blue	0.87	1645	Solid blue
Violet	0.91	1665	Solid violet
White	0.93	1675	Solid white
Black/Off	0.99	1695	All LEDs off

Configuration

Edit these values in src/main.cpp:

#define NUM_LEDS 60        // Number of LEDs in your strip
#define BRIGHTNESS 100     // Brightness (0-255)
#define DEBUG_MODE true    // Serial debug output

Testing & Debugging

1. Serial Monitor: Connect via USB and open serial monitor at 115200 baud

   • Shows current PWM value and selected pattern
   • Displays startup messages and status

2. LED Test: On startup, a green sweep animation indicates the system is ready

3. Manual PWM Test: Use a servo tester to send PWM signals and verify pattern changes

Troubleshooting

LEDs not lighting up

• Check 5V power supply (must provide sufficient current)
• Verify D4 (GPIO2) is connected to LED data line
• Confirm ground connections between all components

Wrong patterns displaying

• Verify voltage divider is working (PWM signal must be ~3.3V)
• Check serial monitor for PWM values (should be 900-2100μs)
• Ensure servo position in FTC code is between 0.0 and 1.0

Erratic behavior

• Add a 1000μF capacitor across LED power lines
• Add a 470Ω resistor between D4 and LED data
• Ensure all grounds are connected together

Pattern doesn't match Blinkin

• Some complex patterns may differ slightly from original Blinkin
• Adjust PWM thresholds in pwmToPattern() function if needed

Power Calculations

• Each WS2812B LED: ~60mA at full white brightness
• 60 LEDs × 60mA = 3.6A maximum
• With brightness set to 100/255: ~1.4A typical
• D1 Mini consumption: ~80mA
• Recommended PSU: 5V 4A minimum

Build Guide Documentation

Additional documentation is available:

• INSTALLATION_GUIDE.md - Detailed setup instructions
• VOLTAGE_DIVIDER_BUILD_GUIDE.md - How to build the voltage divider
• VOLTAGE_DIVIDER_ALTERNATIVES.md - Alternative protection methods
• QUICK_FLASH_GUIDE.md - Quick programming reference

License

This project is open source and available for FTC teams to use and modify.

Credits

Created for Kraken Koders FTC Team Based on REV Blinkin LED Driver patterns and functionality