Adafruit_NeoPixel.h

/*!
 * @file Adafruit_NeoPixel.h
 *
 * This is part of Adafruit's NeoPixel library for the Arduino platform,
 * allowing a broad range of microcontroller boards (most AVR boards,
 * many ARM devices, ESP8266 and ESP32, among others) to control Adafruit
 * NeoPixels, FLORA RGB Smart Pixels and compatible devices -- WS2811,
 * WS2812, WS2812B, SK6812, etc.
 *
 * Adafruit invests time and resources providing this open source code,
 * please support Adafruit and open-source hardware by purchasing products
 * from Adafruit!
 *
 * Written by Phil "Paint Your Dragon" Burgess for Adafruit Industries,
 * with contributions by PJRC, Michael Miller and other members of the
 * open source community.
 *
 * This file is part of the Adafruit_NeoPixel library.
 *
 * Adafruit_NeoPixel is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * Adafruit_NeoPixel is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with NeoPixel.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 */

#ifndef ADAFRUIT_NEOPIXEL_H
#define ADAFRUIT_NEOPIXEL_H

#ifdef ARDUINO
  #if (ARDUINO >= 100)
  #include <Arduino.h>
  #else
  #include <WProgram.h>
  #include <pins_arduino.h>
  #endif
#endif

#ifdef TARGET_LPC1768
  #include <Arduino.h>
#endif

// The order of primary colors in the NeoPixel data stream can vary among
// device types, manufacturers and even different revisions of the same
// item.  The third parameter to the Adafruit_NeoPixel constructor encodes
// the per-pixel byte offsets of the red, green and blue primaries (plus
// white, if present) in the data stream -- the following #defines provide
// an easier-to-use named version for each permutation. e.g. NEO_GRB
// indicates a NeoPixel-compatible device expecting three bytes per pixel,
// with the first byte transmitted containing the green value, second
// containing red and third containing blue. The in-memory representation
// of a chain of NeoPixels is the same as the data-stream order; no
// re-ordering of bytes is required when issuing data to the chain.
// Most of these values won't exist in real-world devices, but it's done
// this way so we're ready for it (also, if using the WS2811 driver IC,
// one might have their pixels set up in any weird permutation).

// Bits 5,4 of this value are the offset (0-3) from the first byte of a
// pixel to the location of the red color byte.  Bits 3,2 are the green
// offset and 1,0 are the blue offset.  If it is an RGBW-type device
// (supporting a white primary in addition to R,G,B), bits 7,6 are the
// offset to the white byte...otherwise, bits 7,6 are set to the same value
// as 5,4 (red) to indicate an RGB (not RGBW) device.
// i.e. binary representation:
// 0bWWRRGGBB for RGBW devices
// 0bRRRRGGBB for RGB

// RGB NeoPixel permutations; white and red offsets are always same
// Offset:         W        R        G        B
#define NEO_RGB  ((0<<6) | (0<<4) | (1<<2) | (2)) ///< Transmit as R,G,B
#define NEO_RBG  ((0<<6) | (0<<4) | (2<<2) | (1)) ///< Transmit as R,B,G
#define NEO_GRB  ((1<<6) | (1<<4) | (0<<2) | (2)) ///< Transmit as G,R,B
#define NEO_GBR  ((2<<6) | (2<<4) | (0<<2) | (1)) ///< Transmit as G,B,R
#define NEO_BRG  ((1<<6) | (1<<4) | (2<<2) | (0)) ///< Transmit as B,R,G
#define NEO_BGR  ((2<<6) | (2<<4) | (1<<2) | (0)) ///< Transmit as B,G,R

// RGBW NeoPixel permutations; all 4 offsets are distinct
// Offset:         W          R          G          B
#define NEO_WRGB ((0<<6) | (1<<4) | (2<<2) | (3)) ///< Transmit as W,R,G,B
#define NEO_WRBG ((0<<6) | (1<<4) | (3<<2) | (2)) ///< Transmit as W,R,B,G
#define NEO_WGRB ((0<<6) | (2<<4) | (1<<2) | (3)) ///< Transmit as W,G,R,B
#define NEO_WGBR ((0<<6) | (3<<4) | (1<<2) | (2)) ///< Transmit as W,G,B,R
#define NEO_WBRG ((0<<6) | (2<<4) | (3<<2) | (1)) ///< Transmit as W,B,R,G
#define NEO_WBGR ((0<<6) | (3<<4) | (2<<2) | (1)) ///< Transmit as W,B,G,R

#define NEO_RWGB ((1<<6) | (0<<4) | (2<<2) | (3)) ///< Transmit as R,W,G,B
#define NEO_RWBG ((1<<6) | (0<<4) | (3<<2) | (2)) ///< Transmit as R,W,B,G
#define NEO_RGWB ((2<<6) | (0<<4) | (1<<2) | (3)) ///< Transmit as R,G,W,B
#define NEO_RGBW ((3<<6) | (0<<4) | (1<<2) | (2)) ///< Transmit as R,G,B,W
#define NEO_RBWG ((2<<6) | (0<<4) | (3<<2) | (1)) ///< Transmit as R,B,W,G
#define NEO_RBGW ((3<<6) | (0<<4) | (2<<2) | (1)) ///< Transmit as R,B,G,W

#define NEO_GWRB ((1<<6) | (2<<4) | (0<<2) | (3)) ///< Transmit as G,W,R,B
#define NEO_GWBR ((1<<6) | (3<<4) | (0<<2) | (2)) ///< Transmit as G,W,B,R
#define NEO_GRWB ((2<<6) | (1<<4) | (0<<2) | (3)) ///< Transmit as G,R,W,B
#define NEO_GRBW ((3<<6) | (1<<4) | (0<<2) | (2)) ///< Transmit as G,R,B,W
#define NEO_GBWR ((2<<6) | (3<<4) | (0<<2) | (1)) ///< Transmit as G,B,W,R
#define NEO_GBRW ((3<<6) | (2<<4) | (0<<2) | (1)) ///< Transmit as G,B,R,W

#define NEO_BWRG ((1<<6) | (2<<4) | (3<<2) | (0)) ///< Transmit as B,W,R,G
#define NEO_BWGR ((1<<6) | (3<<4) | (2<<2) | (0)) ///< Transmit as B,W,G,R
#define NEO_BRWG ((2<<6) | (1<<4) | (3<<2) | (0)) ///< Transmit as B,R,W,G
#define NEO_BRGW ((3<<6) | (1<<4) | (2<<2) | (0)) ///< Transmit as B,R,G,W
#define NEO_BGWR ((2<<6) | (3<<4) | (1<<2) | (0)) ///< Transmit as B,G,W,R
#define NEO_BGRW ((3<<6) | (2<<4) | (1<<2) | (0)) ///< Transmit as B,G,R,W

// Add NEO_KHZ400 to the color order value to indicate a 400 KHz device.
// All but the earliest v1 NeoPixels expect an 800 KHz data stream, this is
// the default if unspecified. Because flash space is very limited on ATtiny
// devices (e.g. Trinket, Gemma), v1 NeoPixels aren't handled by default on
// those chips, though it can be enabled by removing the ifndef/endif below,
// but code will be bigger. Conversely, can disable the NEO_KHZ400 line on
// other MCUs to remove v1 support and save a little space.

#define NEO_KHZ800 0x0000 ///< 800 KHz data transmission
#ifndef __AVR_ATtiny85__
#define NEO_KHZ400 0x0100 ///< 400 KHz data transmission
#endif

// If 400 KHz support is enabled, the third parameter to the constructor
// requires a 16-bit value (in order to select 400 vs 800 KHz speed).
// If only 800 KHz is enabled (as is default on ATtiny), an 8-bit value
// is sufficient to encode pixel color order, saving some space.

#ifdef NEO_KHZ400
typedef uint16_t neoPixelType; ///< 3rd arg to Adafruit_NeoPixel constructor
#else
typedef uint8_t  neoPixelType; ///< 3rd arg to Adafruit_NeoPixel constructor
#endif

// These two tables are declared outside the Adafruit_NeoPixel class
// because some boards may require oldschool compilers that don't
// handle the C++11 constexpr keyword.

/* A PROGMEM (flash mem) table containing 8-bit unsigned sine wave (0-255).
   Copy & paste this snippet into a Python REPL to regenerate:
import math
for x in range(256):
    print("{:3},".format(int((math.sin(x/128.0*math.pi)+1.0)*127.5+0.5))),
    if x&15 == 15: print
*/
static const uint8_t PROGMEM _NeoPixelSineTable[256] = {
  128,131,134,137,140,143,146,149,152,155,158,162,165,167,170,173,
  176,179,182,185,188,190,193,196,198,201,203,206,208,211,213,215,
  218,220,222,224,226,228,230,232,234,235,237,238,240,241,243,244,
  245,246,248,249,250,250,251,252,253,253,254,254,254,255,255,255,
  255,255,255,255,254,254,254,253,253,252,251,250,250,249,248,246,
  245,244,243,241,240,238,237,235,234,232,230,228,226,224,222,220,
  218,215,213,211,208,206,203,201,198,196,193,190,188,185,182,179,
  176,173,170,167,165,162,158,155,152,149,146,143,140,137,134,131,
  128,124,121,118,115,112,109,106,103,100, 97, 93, 90, 88, 85, 82,
   79, 76, 73, 70, 67, 65, 62, 59, 57, 54, 52, 49, 47, 44, 42, 40,
   37, 35, 33, 31, 29, 27, 25, 23, 21, 20, 18, 17, 15, 14, 12, 11,
   10,  9,  7,  6,  5,  5,  4,  3,  2,  2,  1,  1,  1,  0,  0,  0,
    0,  0,  0,  0,  1,  1,  1,  2,  2,  3,  4,  5,  5,  6,  7,  9,
   10, 11, 12, 14, 15, 17, 18, 20, 21, 23, 25, 27, 29, 31, 33, 35,
   37, 40, 42, 44, 47, 49, 52, 54, 57, 59, 62, 65, 67, 70, 73, 76,
   79, 82, 85, 88, 90, 93, 97,100,103,106,109,112,115,118,121,124};

/* Similar to above, but for an 8-bit gamma-correction table.
   Copy & paste this snippet into a Python REPL to regenerate:
import math
gamma=2.6
for x in range(256):
    print("{:3},".format(int(math.pow((x)/255.0,gamma)*255.0+0.5))),
    if x&15 == 15: print
*/
static const uint8_t PROGMEM _NeoPixelGammaTable[256] = {
    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
    0,  0,  0,  0,  0,  0,  0,  0,  1,  1,  1,  1,  1,  1,  1,  1,
    1,  1,  1,  1,  2,  2,  2,  2,  2,  2,  2,  2,  3,  3,  3,  3,
    3,  3,  4,  4,  4,  4,  5,  5,  5,  5,  5,  6,  6,  6,  6,  7,
    7,  7,  8,  8,  8,  9,  9,  9, 10, 10, 10, 11, 11, 11, 12, 12,
   13, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 20,
   20, 21, 21, 22, 22, 23, 24, 24, 25, 25, 26, 27, 27, 28, 29, 29,
   30, 31, 31, 32, 33, 34, 34, 35, 36, 37, 38, 38, 39, 40, 41, 42,
   42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
   58, 59, 60, 61, 62, 63, 64, 65, 66, 68, 69, 70, 71, 72, 73, 75,
   76, 77, 78, 80, 81, 82, 84, 85, 86, 88, 89, 90, 92, 93, 94, 96,
   97, 99,100,102,103,105,106,108,109,111,112,114,115,117,119,120,
  122,124,125,127,129,130,132,134,136,137,139,141,143,145,146,148,
  150,152,154,156,158,160,162,164,166,168,170,172,174,176,178,180,
  182,184,186,188,191,193,195,197,199,202,204,206,209,211,213,215,
  218,220,223,225,227,230,232,235,237,240,242,245,247,250,252,255};

/*! 
    @brief  Class that stores state and functions for interacting with
            Adafruit NeoPixels and compatible devices.
*/
class Adafruit_NeoPixel {

 public:

  // Constructor: number of LEDs, pin number, LED type
  Adafruit_NeoPixel(uint16_t n, uint16_t pin=6,
    neoPixelType type=NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel(void);
  ~Adafruit_NeoPixel();

  void              begin(void);
  void              show(void);
  void              setPin(uint16_t p);
  void              setPixelColor(uint16_t n, uint8_t r, uint8_t g, uint8_t b);
  void              setPixelColor(uint16_t n, uint8_t r, uint8_t g, uint8_t b,
                      uint8_t w);
  void              setPixelColor(uint16_t n, uint32_t c);
  void              fill(uint32_t c=0, uint16_t first=0, uint16_t count=0);
  void              setBrightness(uint8_t);
  void              clear(void);
  void              updateLength(uint16_t n);
  void              updateType(neoPixelType t);
  /*!
    @brief   Check whether a call to show() will start sending data
             immediately or will 'block' for a required interval. NeoPixels
             require a short quiet time (about 300 microseconds) after the
             last bit is received before the data 'latches' and new data can
             start being received. Usually one's sketch is implicitly using
             this time to generate a new frame of animation...but if it
             finishes very quickly, this function could be used to see if
             there's some idle time available for some low-priority
             concurrent task.
    @return  1 or true if show() will start sending immediately, 0 or false
             if show() would block (meaning some idle time is available).
  */
  boolean           canShow(void) const { return (micros()-endTime) >= 300L; }
  /*!
    @brief   Get a pointer directly to the NeoPixel data buffer in RAM.
             Pixel data is stored in a device-native format (a la the NEO_*
             constants) and is not translated here. Applications that access
             this buffer will need to be aware of the specific data format
             and handle colors appropriately.
    @return  Pointer to NeoPixel buffer (uint8_t* array).
    @note    This is for high-performance applications where calling
             setPixelColor() on every single pixel would be too slow (e.g.
             POV or light-painting projects). There is no bounds checking
             on the array, creating tremendous potential for mayhem if one
             writes past the ends of the buffer. Great power, great
             responsibility and all that.
  */
  uint8_t          *getPixels(void) const { return pixels; };
  uint8_t           getBrightness(void) const;
  /*!
    @brief   Retrieve the pin number used for NeoPixel data output.
    @return  Arduino pin number (-1 if not set).
  */
  int16_t           getPin(void) const { return pin; };
  /*!
    @brief   Return the number of pixels in an Adafruit_NeoPixel strip object.
    @return  Pixel count (0 if not set).
  */
  uint16_t          numPixels(void) const { return numLEDs; }
  uint32_t          getPixelColor(uint16_t n) const;
  /*!
    @brief   An 8-bit integer sine wave function, not directly compatible
             with standard trigonometric units like radians or degrees.
    @param   x  Input angle, 0-255; 256 would loop back to zero, completing
                the circle (equivalent to 360 degrees or 2 pi radians).
                One can therefore use an unsigned 8-bit variable and simply
                add or subtract, allowing it to overflow/underflow and it
                still does the expected contiguous thing.
    @return  Sine result, 0 to 255, or -128 to +127 if type-converted to
             a signed int8_t, but you'll most likely want unsigned as this
             output is often used for pixel brightness in animation effects.
  */
  static uint8_t    sine8(uint8_t x) {
    return pgm_read_byte(&_NeoPixelSineTable[x]); // 0-255 in, 0-255 out
  }
  /*!
    @brief   An 8-bit gamma-correction function for basic pixel brightness
             adjustment. Makes color transitions appear more perceptially
             correct.
    @param   x  Input brightness, 0 (minimum or off/black) to 255 (maximum).
    @return  Gamma-adjusted brightness, can then be passed to one of the
             setPixelColor() functions. This uses a fixed gamma correction
             exponent of 2.6, which seems reasonably okay for average
             NeoPixels in average tasks. If you need finer control you'll
             need to provide your own gamma-correction function instead.
  */
  static uint8_t    gamma8(uint8_t x) {
    return pgm_read_byte(&_NeoPixelGammaTable[x]); // 0-255 in, 0-255 out
  }
  /*!
    @brief   Convert separate red, green and blue values into a single
             "packed" 32-bit RGB color.
    @param   r  Red brightness, 0 to 255.
    @param   g  Green brightness, 0 to 255.
    @param   b  Blue brightness, 0 to 255.
    @return  32-bit packed RGB value, which can then be assigned to a
             variable for later use or passed to the setPixelColor()
             function. Packed RGB format is predictable, regardless of
             LED strand color order.
  */
  static uint32_t   Color(uint8_t r, uint8_t g, uint8_t b) {
    return ((uint32_t)r << 16) | ((uint32_t)g <<  8) | b;
  }
  /*!
    @brief   Convert separate red, green, blue and white values into a
             single "packed" 32-bit WRGB color.
    @param   r  Red brightness, 0 to 255.
    @param   g  Green brightness, 0 to 255.
    @param   b  Blue brightness, 0 to 255.
    @param   w  White brightness, 0 to 255.
    @return  32-bit packed WRGB value, which can then be assigned to a
             variable for later use or passed to the setPixelColor()
             function. Packed WRGB format is predictable, regardless of
             LED strand color order.
  */
  static uint32_t   Color(uint8_t r, uint8_t g, uint8_t b, uint8_t w) {
    return ((uint32_t)w << 24) | ((uint32_t)r << 16) | ((uint32_t)g <<  8) | b;
  }
  static uint32_t   ColorHSV(uint16_t hue, uint8_t sat=255, uint8_t val=255);
  /*!
    @brief   A gamma-correction function for 32-bit packed RGB or WRGB
             colors. Makes color transitions appear more perceptially
             correct.
    @param   x  32-bit packed RGB or WRGB color.
    @return  Gamma-adjusted packed color, can then be passed in one of the
             setPixelColor() functions. Like gamma8(), this uses a fixed
             gamma correction exponent of 2.6, which seems reasonably okay
             for average NeoPixels in average tasks. If you need finer
             control you'll need to provide your own gamma-correction
             function instead.
  */
  static uint32_t   gamma32(uint32_t x);

 protected:

#ifdef NEO_KHZ400  // If 400 KHz NeoPixel support enabled...
  boolean           is800KHz;   ///< true if 800 KHz pixels
#endif
  boolean           begun;      ///< true if begin() previously called
  uint16_t          numLEDs;    ///< Number of RGB LEDs in strip
  uint16_t          numBytes;   ///< Size of 'pixels' buffer below
  int16_t           pin;        ///< Output pin number (-1 if not yet set)
  uint8_t           brightness; ///< Strip brightness 0-255 (stored as +1)
  uint8_t          *pixels;     ///< Holds LED color values (3 or 4 bytes each)
  uint8_t           rOffset;    ///< Red index within each 3- or 4-byte pixel
  uint8_t           gOffset;    ///< Index of green byte
  uint8_t           bOffset;    ///< Index of blue byte
  uint8_t           wOffset;    ///< Index of white (==rOffset if no white)
  uint32_t          endTime;    ///< Latch timing reference
#ifdef __AVR__
  volatile uint8_t *port;       ///< Output PORT register
  uint8_t           pinMask;    ///< Output PORT bitmask
#endif
};

#endif // ADAFRUIT_NEOPIXEL_H