This sketch fixes a minor bug that existed in the last code published by RobertL184. It works with Arduino 1.8.3 and the NeoPixel library v1.1.1

If you want to change the pin that the arduino is connecting to the NeoPixel on, change the 2nd parameter in line 321. If you want to change the number of NeoPixles in the ring or device, change the first parameter in line 321.

Example

NeoPatterns Ring1(24, 6, NEO_GRB + NEO_KHZ800, &Ring1Complete);

is for a 24 pixel NeoPixel that has its input pin connected to pin 6 on the Arduino.

/* real time Serial Controlled Neopixel Ring  -- Code not tested yet
/
/ Serial Commands
/     Cr1,g1,b1  - Set whole Ring to same color specified by r1,g1,b1
/     Rt,d  - Rainbow  with interval t and direction d
/     Tr1,g1,b1,r2,g2,b2,t,d - Theater Chase between color r1,g1,b1 and color r2,g2,b2 with interval t and direction d
/     Wr1,g1,b1,t,d - Color Wipe in  color r1,g1,b1 with interval t and direction d
/     Fr1,g1,b1,r2,g2,b2,s,t,d - Fade between color r1,g1,b1 and color r2,g2,b2 in s steps with interval t and direction d
/     Sr1,g1,b1,t  - Scanner with color specified by r1,g1,b1 and interval t
/     Pp,r1,g1,b1 - Set individual pixel p to color specified by r1,g1,b1
/
/    p = pixel number
/    r1 = 1st color red values 0 to 255
/    g1 = 1st color greern values 0 to 255
/    b1 = 1st color blue values 0 to 255
/    r2 = 2nd color red values 0 to 255
/    g2 = 2nd color greern values 0 to 255
/    b2 = 2nd color blue values 0 to 255
/    s = number of steps
/    t = interval time values 0 to 255
/    d = direction  0 = Forward 1 = Backward  
*/

#include <Adafruit_NeoPixel.h>
 
// Pattern types supported:
enum  pattern { NONE, RAINBOW_CYCLE, THEATER_CHASE, COLOR_WIPE, SCANNER, FADE };
// Patern directions supported:
enum  direction { FORWARD, REVERSE };
 
// NeoPattern Class - derived from the Adafruit_NeoPixel class
class NeoPatterns : public Adafruit_NeoPixel
{
    public:
 
    // Member Variables:  
    pattern  ActivePattern;  // which pattern is running
    direction Direction;     // direction to run the pattern
    
    unsigned long Interval;   // milliseconds between updates
    unsigned long lastUpdate; // last update of position
    
    uint32_t Color1, Color2;  // What colors are in use
    uint16_t TotalSteps;  // total number of steps in the pattern
    uint16_t Index;  // current step within the pattern
    
    void (*OnComplete)();  // Callback on completion of pattern
    
    // Constructor - calls base-class constructor to initialize strip
    NeoPatterns(uint16_t pixels, uint8_t pin, uint8_t type, void (*callback)())
    :Adafruit_NeoPixel(pixels, pin, type)
    {
        OnComplete = callback;
    }
    
    // Update the pattern
    void Update()
    {
        if((millis() - lastUpdate) > Interval) // time to update
        {
            lastUpdate = millis();
            switch(ActivePattern)
            {
                case RAINBOW_CYCLE:
                    RainbowCycleUpdate();
                    break;
                case THEATER_CHASE:
                    TheaterChaseUpdate();
                    break;
                case COLOR_WIPE:
                    ColorWipeUpdate();
                    break;
                case SCANNER:
                    ScannerUpdate();
                    break;
                case FADE:
                    FadeUpdate();
                    break;
                default:
                    break;
            }
        }
    }
  
    // Increment the Index and reset at the end
    void Increment()
    {
        if (Direction == FORWARD)
        {
           Index++;
           if (Index >= TotalSteps)
            {
                Index = 0;
                if (OnComplete != NULL)
                {
                    OnComplete(); // call the comlpetion callback
                }
            }
        }
        else // Direction == REVERSE
        {
            --Index;
            if (Index <= 0)
            {
                Index = TotalSteps-1;
                if (OnComplete != NULL)
                {
                    OnComplete(); // call the comlpetion callback
                }
            }
        }
    }
    
    // Reverse pattern direction
    void Reverse()
    {
        if (Direction == FORWARD)
        {
            Direction = REVERSE;
            Index = TotalSteps-1;
        }
        else
        {
            Direction = FORWARD;
            Index = 0;
        }
    }
//------------------------------------------------------------
//Completion Routines - get called on completion of a pattern
//------------------------------------------------------------
 
    // Initialize for a RainbowCycle
    void RainbowCycle(uint8_t interval, direction dir = FORWARD)
    {
        ActivePattern = RAINBOW_CYCLE;
        Interval = interval;
        TotalSteps = 255;
        Index = 0;
        Direction = dir;
    }
    
    // Update the Rainbow Cycle Pattern
    void RainbowCycleUpdate()
    {
        for(int i=0; i< numPixels(); i++)
        {
            setPixelColor(i, Wheel(((i * 256 / numPixels()) + Index) & 255));
        }
        show();
        Increment();
    }
 
    // Initialize for a Theater Chase
    void TheaterChase(uint32_t color1, uint32_t color2, uint8_t interval, direction dir = FORWARD)
    {
        ActivePattern = THEATER_CHASE;
        Interval = interval;
        TotalSteps = numPixels();
        Color1 = color1;
        Color2 = color2;
        Index = 0;
        Direction = dir;
   }
    
    // Update the Theater Chase Pattern
    void TheaterChaseUpdate()
    {
        for(int i=0; i< numPixels(); i++)
        {
            if ((i + Index) % 3 == 0)
            {
                setPixelColor(i, Color1);
            }
            else
            {
                setPixelColor(i, Color2);
            }
        }
        show();
        Increment();
    }
 
    // Initialize for a ColorWipe
    void ColorWipe(uint32_t color, uint8_t interval, direction dir = FORWARD)
    {
        ActivePattern = COLOR_WIPE;
        Interval = interval;
        TotalSteps = numPixels();
        Color1 = color;
        Index = 0;
        Direction = dir;
    }
    
    // Update the Color Wipe Pattern
    void ColorWipeUpdate()
    {
        setPixelColor(Index, Color1);
        show();
        Increment();
    }
    
    // Initialize for a SCANNNER
    void Scanner(uint32_t color1, uint8_t interval)
    {
        ActivePattern = SCANNER;
        Interval = interval;
        TotalSteps = (numPixels() - 1) * 2;
        Color1 = color1;
        Index = 0;
    }
 
    // Update the Scanner Pattern
    void ScannerUpdate()
    { 
        for (int i = 0; i < numPixels(); i++)
        {
            if (i == Index)  // Scan Pixel to the right
            {
                 setPixelColor(i, Color1);
            }
            else if (i == TotalSteps - Index) // Scan Pixel to the left
            {
                 setPixelColor(i, Color1);
            }
            else // Fading tail
            {
                 setPixelColor(i, DimColor(getPixelColor(i)));
            }
        }
        show();
        Increment();
    }
    
    // Initialize for a Fade
    void Fade(uint32_t color1, uint32_t color2, uint16_t steps, uint8_t interval, direction dir = FORWARD)
    {
        ActivePattern = FADE;
        Interval = interval;
        TotalSteps = steps;
        Color1 = color1;
        Color2 = color2;
        Index = 0;
        Direction = dir;
    }
    
    // Update the Fade Pattern
    void FadeUpdate()
    {
        // Calculate linear interpolation between Color1 and Color2
        // Optimise order of operations to minimize truncation error
        uint8_t red = ((Red(Color1) * (TotalSteps - Index)) + (Red(Color2) * Index)) / TotalSteps;
        uint8_t green = ((Green(Color1) * (TotalSteps - Index)) + (Green(Color2) * Index)) / TotalSteps;
        uint8_t blue = ((Blue(Color1) * (TotalSteps - Index)) + (Blue(Color2) * Index)) / TotalSteps;
        
        ColorSet(Color(red, green, blue));
        show();
        Increment();
    }
   
    // Calculate 50% dimmed version of a color (used by ScannerUpdate)
    uint32_t DimColor(uint32_t color)
    {
        // Shift R, G and B components one bit to the right
        uint32_t dimColor = Color(Red(color) >> 1, Green(color) >> 1, Blue(color) >> 1);
        return dimColor;
    }
 
    // Set all pixels to a color (synchronously)
    void ColorSet(uint32_t color)
    {
        for (int i = 0; i < numPixels(); i++)
        {
            setPixelColor(i, color);
        }
        show();
    }
 
    // Returns the Red component of a 32-bit color
    uint8_t Red(uint32_t color)
    {
        return (color >> 16) & 0xFF;
    }
 
    // Returns the Green component of a 32-bit color
    uint8_t Green(uint32_t color)
    {
        return (color >> 8) & 0xFF;
    }
 
    // Returns the Blue component of a 32-bit color
    uint8_t Blue(uint32_t color)
    {
        return color & 0xFF;
    }
    
    // Input a value 0 to 255 to get a color value.
    // The colours are a transition r - g - b - back to r.
    uint32_t Wheel(byte WheelPos)
    {
        WheelPos = 255 - WheelPos;
        if(WheelPos < 85)
        {
            return Color(255 - WheelPos * 3, 0, WheelPos * 3);
        }
        else if(WheelPos < 170)
        {
            WheelPos -= 85;
            return Color(0, WheelPos * 3, 255 - WheelPos * 3);
        }
        else
        {
            WheelPos -= 170;
            return Color(WheelPos * 3, 255 - WheelPos * 3, 0);
        }
    }
};
void Ring1Complete();
 
// Define some NeoPatterns for the two rings and the stick
//  as well as some completion routines
NeoPatterns Ring1(24, 6, NEO_GRB + NEO_KHZ800, &Ring1Complete);

int red1 = 0;              // red value 
int green1 = 34;           // green value
int blue1 = 12;            // blue value
int red2 = 0;              // red value 
int green2 = 34;           // green value
int blue2 = 12;            // blue value
int my_pixel = 0;          // pixel number
int s = 5;                 // step value
int t = 10;                // interval time value
int d = 0;                  // direction indicator 0= Forward 1 = Backward

// Initialize everything and prepare to start
void setup()
{
  Serial.begin(9600);
  Serial.setTimeout(10);  // set serial timeout

    // Initialize all the pixelStrips
    Ring1.begin();
    Ring1.ColorSet(Ring1.Color(0, 0, 0));
}
 
// Main loop
void loop()
{
int inchar;
  
  if (Serial.available() > 0) {
    inchar = Serial.read();
    if ( inchar == 'C') {    // string should start with C
      red1 = Serial.parseInt();     // then an ASCII number for red
      green1 = Serial.parseInt();   // then an ASCII number for green
      blue1 = Serial.parseInt();    // then an ASCII number for blue
      Ring1.ActivePattern = NONE;
      Ring1.ColorSet(Ring1.Color(red1, green1, blue1));
    }
    if ( inchar == 'R') {    // string should start with R
      t = Serial.parseInt();     // then an ASCII number for interval
      d = Serial.parseInt();    // then an ASCII number for direction
      if (d ==0) {
         Ring1.RainbowCycle(t, FORWARD);
      } else {
         Ring1.RainbowCycle(t, REVERSE);
      }
    }
    if ( inchar == 'F') {    // string should start with F
      red1 = Serial.parseInt();     // then an ASCII number for red
      green1 = Serial.parseInt();   // then an ASCII number for green
      blue1 = Serial.parseInt();    // then an ASCII number for blue
      red2 = Serial.parseInt();     // then an ASCII number for red
      green2 = Serial.parseInt();   // then an ASCII number for green
      blue2 = Serial.parseInt();    // then an ASCII number for blue
      s = Serial.parseInt();        // then an ASCII number for steps
      t = Serial.parseInt();        // then an ASCII number for interval
      d = Serial.parseInt();        // then an ASCII number for direction
      if (d ==0) {
        Ring1.Fade(Ring1.Color(red1, green1, blue1), Ring1.Color(red2, green2, blue2), s, t, FORWARD); 
      } else {
        Ring1.Fade(Ring1.Color(red1, green1, blue1), Ring1.Color(red2, green2, blue2), s, t, REVERSE); 
      }
    }
    if ( inchar == 'T') {    // string should start with T
      red1 = Serial.parseInt();     // then an ASCII number for red
      green1 = Serial.parseInt();   // then an ASCII number for green
      blue1 = Serial.parseInt();    // then an ASCII number for blue
      red2 = Serial.parseInt();     // then an ASCII number for red
      green2 = Serial.parseInt();   // then an ASCII number for green
      blue2 = Serial.parseInt();    // then an ASCII number for blue
      t = Serial.parseInt();        // then an ASCII number for interval
      d = Serial.parseInt();        // then an ASCII number for direction
      if (d ==0) {
        Ring1.TheaterChase(Ring1.Color(red1, green1, blue1), Ring1.Color(red2, green2, blue2), t, FORWARD);
      } else {
        Ring1.TheaterChase(Ring1.Color(red1, green1, blue1), Ring1.Color(red2, green2, blue2), t, REVERSE);
      }
    }
    if ( inchar == 'W') {    // string should start with W
      red1 = Serial.parseInt();     // then an ASCII number for red
      green1 = Serial.parseInt();   // then an ASCII number for green
      blue1 = Serial.parseInt();    // then an ASCII number for blue
      t = Serial.parseInt();        // then an ASCII number for interval
      d = Serial.parseInt();        // then an ASCII number for direction
      if (d ==0) {
        Ring1.ColorWipe(Ring1.Color(red1, green1, blue1), t, FORWARD);
      } else {
        Ring1.ColorWipe(Ring1.Color(red1, green1, blue1), t, REVERSE);
      }
    }
    if ( inchar == 'S') {    // string should start with S
      red1 = Serial.parseInt();     // then an ASCII number for red
      green1 = Serial.parseInt();   // then an ASCII number for green
      blue1 = Serial.parseInt();    // then an ASCII number for blue
      t = Serial.parseInt();        // then an ASCII number for interval
      Ring1.ColorWipe(Ring1.Color(red1, green1, blue1), 50, FORWARD);
      Ring1.ColorSet(Ring1.Color(0,0, 0));
      Ring1.Scanner(Ring1.Color(red1, green1, blue1), t);
     }
     if ( inchar == 'P') {    // string should start with P
      my_pixel = Serial.parseInt();     // then an ASCII number for pixwel
      red1 = Serial.parseInt();     // then an ASCII number for red
      green1 = Serial.parseInt();   // then an ASCII number for green
      blue1 = Serial.parseInt();    // then an ASCII number for blue
      Ring1.ActivePattern = NONE;
      Ring1.setPixelColor(my_pixel, Ring1.Color(red1, green1, blue1));
      Ring1.show();
    }
 } 

  // Update the ring.
    Ring1.Update();
}
// Ring1 Completion Callback
void Ring1Complete()
{
  if ((Ring1.ActivePattern == RAINBOW_CYCLE) || (Ring1.ActivePattern == FADE) ||
      (Ring1.ActivePattern == THEATER_CHASE) || (Ring1.ActivePattern == SCANNER)){
    Ring1.Reverse();
      }
}

This will work with the plugin still. The commands don't change so there is no modification to the plugin.