The change in architecture from the classic AVR to the "modern AVR" of the tinyAVR 0-series and 1-series parts (and megaAVR 0-series parts) causes many of the existing WS2812 libraries to not work on the these parts. This library adapts the Adafruit_NeoPixel library to work with the improved architecture, and adds support for 10MHz and 20MHz clock speeds. Unlike in ATTinyCore, where slower clock speeds require a separate implementation (chosen via a menu option in that case) depending on which PORT the pin being used is on, these parts do not need this, because the indirect ST instruction executes in a single clock cycle instead of 2. Prior to version 2.0.2, this was not realized, and there were issues with real WS2812B LEDs (as opposed to SK6812 clones) in addition to a requirement for awkward port-dependant methods of calling the library.
There are two versions of this library provided. tinyNeoPixel implements the entire API that Adafruit_NeoPixel does, including setting the pin and length of the string at runtime. This provides maximum portability between code written for use with Adafruit_NeoPixel and tinyNeoPixel (only the constructor and library name need to be changed).
tinyNeoPixel_Static is slightly cutdown, removing the option to change the length at runtime, and instead of using malloc() to dynamically allocate the pixel buffer, the user must declare the pixel buffer and pass it to the constructor. Additionally, it does not set the pinMode of the pin (the sketch must set this as OUTPUT). Finally, no call to begin() need be made - begin() is removed entirely. These changes reduce flash use (by eliminating malloc() and free(), and because the pixel buffer is statically declared, the memory used for it is included in count of used SRAM output when the sketch is compiled. Removal of the pinMode() call within the library, while it requires an additional line of code in the sketch, opens the option of eliminating all calls to pinMode() from a sketch (replacing with direct port manipulation) when maximum flash savings is required.
tinyNeoPixel(uint16_t n, uint8_t p=6, neoPixelType t=NEO_GRB) constructor for tinyNeoPixel - the first argument is is the number of LEDs in the string, the second is the pin, and the final argument is the color order of the LEDs in use; the library provides #defines for every possible color order for RGB and RGBW LEDs (full list below).
tinyNeoPixel() - empty constructor, set pin and length later with setPin(), updateLength(), and updateType().
tinyNeoPixel(uint16_t n, uint8_t p, neoPixelType t,uint8_t *pxl); constructor for tinyNeoPixel_Static - the final argument is a uint_8 (byte) array sized to accomodate the data to be sent to the LED. For example:
#include <"tinyNeoPixel_Static.h">
#define NUMLEDS 10
byte pixels[NUMLEDS*3];
tinyNeoPixel(NUMPIXELS, 5, NEO_GRB, pixels); //pin 5 is on PORT B on all parts except the 8-pin ones
void setup() {
pinMode(5,OUTPUT);
}
begin() Enable the LEDs, on tinyNeoPixel, must be called before show() - not applicable for tinyNeoPixel_Static
show() Output the contents of the pixel buffer to the LEDs
setPixelColor(uint16_t n, uint8_t r, uint8_t g, uint8_t b) set the color of pixel n to the color r,g,b (for RGB LEDs)
setPixelColor(uint16_t n, uint8_t r, uint8_t g, uint8_t b, uint8_t w) set the color of pixel n to the color r,g,b,w (for RGBW LEDs)
setPixelColor(uint16_t n, uint32_t c) set the color of pixel n to color c (expressed as a uint_32 - as returned from getColor())
setBrightness(uint8_t) set the brightness for the whole string (0~255)
clear() clear the pixel buffer (set all colors on all LEDs to 0)
setPin(uint8_t p) Set the pin for output. At 8 or 10MHz, this must be on the port selected from the tools -> tinyNeoPixel Port submenu. Note that in tinyNeoPixel, the old pin is set as input, and the new pin is set as OUTPUT and written LOW. This is not done on tinyNeoPixel_Static for the reasons described above.
updateLength(uint16_t n) Set the length of the string of LEDs. Not available on tinyNeoPixel_Static.
updateType(neoPixelType t) Set the color order. Not available on tinyNeoPixel_Static.
getPixels() Returns a pointer to the pixel buffer (a uint_8 array).
getBrightness() Returns the current brightness setting (per setBrightness())
getPin() Returns the current pin number.
numPixels() Returns the number of LEDs in the string
Color(uint8_t r, uint8_t g, uint8_t b) Return the color r,g,b as a uint_32 (For RGB leds)
Color(uint8_t r, uint8_t g, uint8_t b, uint8_t w) Return the color r,g,b,w as a uint_32 (For RGBW leds)
getPixelColor(uint16_t n) Returns the color of pin n as a uint_32
These are the same names for the #defines used by Adafruit_NeoPixel; these are used for the third argument to tinyNeoPixel().
NEO_RGB
NEO_RBG
NEO_GRB
NEO_GBR
NEO_BRG
NEO_BGR
NEO_WRGB
NEO_WRBG
NEO_WGRB
NEO_WGBR
NEO_WBRG
NEO_WBGR
NEO_RWGB
NEO_RWBG
NEO_RGWB
NEO_RGBW
NEO_RBWG
NEO_RBGW
NEO_GWRB
NEO_GWBR
NEO_GRWB
NEO_GRBW
NEO_GBWR
NEO_GBRW
NEO_BWRG
NEO_BWGR
NEO_BRWG
NEO_BRGW
NEO_BGWR
NEO_BGRW