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#include "Adafruit_WS2801.h"
// Example to control WS2801-based RGB LED Modules in a strand or strip
// Written by Adafruit - MIT license
/*****************************************************************************/
#ifdef __AVR_ATtiny85__
// Teensy/Gemma-specific stuff for hardware-assisted SPI @ 1 MHz
#if(F_CPU > 8000000L)
#define SPI_DELAY asm volatile("rjmp .+0\nrjmp .+0"); // Burn 4 cycles
#elif(F_CPU > 4000000L)
#define SPI_DELAY asm volatile("rjmp .+0"); // Burn 2 cycles
#else
#define SPI_DELAY // Run max speed
#endif
#define SPIBIT \
USICR = ((1<<USIWM0)|(1<<USITC)); \
SPI_DELAY \
USICR = ((1<<USIWM0)|(1<<USITC)|(1<<USICLK)); \
SPI_DELAY
static void spi_out(uint8_t n) {
USIDR = n;
SPIBIT
SPIBIT
SPIBIT
SPIBIT
SPIBIT
SPIBIT
SPIBIT
SPIBIT
}
#else
// All other boards support Full and Proper Hardware SPI
#include <SPI.h>
#define spi_out(n) (void)SPI.transfer(n)
#endif
/*****************************************************************************/
// Constructor for use with hardware SPI (specific clock/data pins):
Adafruit_WS2801::Adafruit_WS2801(uint16_t n, uint8_t order) {
rgb_order = order;
alloc(n);
updatePins();
}
// Constructor for use with arbitrary clock/data pins:
Adafruit_WS2801::Adafruit_WS2801(uint16_t n, uint8_t dpin, uint8_t cpin, uint8_t order) {
rgb_order = order;
alloc(n);
updatePins(dpin, cpin);
}
// Constructor for use with a matrix configuration, specify w, h for size
// of matrix. Assumes configuration where string starts at coordinate 0,0
// and continues to w-1,0, w-1,1 and on to 0,1, 0,2 and on to w-1,2 and
// so on. Snaking back and forth till the end. Other function calls
// provide access to pixels via an x,y coordinate system
Adafruit_WS2801::Adafruit_WS2801(uint16_t w, uint16_t h, uint8_t dpin, uint8_t cpin, uint8_t order) {
rgb_order = order;
alloc(w * h);
width = w;
height = h;
updatePins(dpin, cpin);
}
// Allocate 3 bytes per pixel, init to RGB 'off' state:
void Adafruit_WS2801::alloc(uint16_t n) {
begun = false;
numLEDs = ((pixels = (uint8_t *)calloc(n, 3)) != NULL) ? n : 0;
}
// via Michael Vogt/neophob: empty constructor is used when strand length
// isn't known at compile-time; situations where program config might be
// read from internal flash memory or an SD card, or arrive via serial
// command. If using this constructor, MUST follow up with updateLength()
// and updatePins() to establish the strand length and output pins!
// Also, updateOrder() to change RGB vs GRB order (RGB is default).
Adafruit_WS2801::Adafruit_WS2801(void) {
begun = false;
numLEDs = 0;
pixels = NULL;
rgb_order = WS2801_RGB;
updatePins(); // Must assume hardware SPI until pins are set
}
// Release memory (as needed):
Adafruit_WS2801::~Adafruit_WS2801(void) {
if(pixels) free(pixels);
}
// Activate hard/soft SPI as appropriate:
void Adafruit_WS2801::begin(void) {
if(hardwareSPI == true) {
startSPI();
} else {
pinMode(datapin, OUTPUT);
pinMode(clkpin , OUTPUT);
}
begun = true;
}
// Change pin assignments post-constructor, switching to hardware SPI:
void Adafruit_WS2801::updatePins(void) {
pinMode(datapin, INPUT); // Restore data and clock pins to inputs
pinMode(clkpin , INPUT);
datapin = clkpin = 0;
hardwareSPI = true;
// If begin() was previously invoked, init the SPI hardware now:
if(begun == true) startSPI();
// Otherwise, SPI is NOT initted until begin() is explicitly called.
}
// Change pin assignments post-constructor, using arbitrary pins:
void Adafruit_WS2801::updatePins(uint8_t dpin, uint8_t cpin) {
if(begun == true) { // If begin() was previously invoked...
// If previously using hardware SPI, turn that off:
if(hardwareSPI) {
#ifdef __AVR_ATtiny85__
DDRB &= ~(_BV(PORTB1) | _BV(PORTB2));
#else
SPI.end();
#endif
} else {
pinMode(datapin, INPUT); // Restore prior data and clock pins to inputs
pinMode(clkpin , INPUT);
}
pinMode(dpin, OUTPUT); // Enable output on 'soft' SPI pins:
pinMode(cpin, OUTPUT);
}
datapin = dpin;
clkpin = cpin;
#ifdef __AVR__
clkport = portOutputRegister(digitalPinToPort(cpin));
clkpinmask = digitalPinToBitMask(cpin);
dataport = portOutputRegister(digitalPinToPort(dpin));
datapinmask = digitalPinToBitMask(dpin);
#endif
hardwareSPI = false;
}
// Enable SPI hardware and set up protocol details:
void Adafruit_WS2801::startSPI(void) {
#ifdef __AVR_ATtiny85__
PORTB &= ~(_BV(PORTB1) | _BV(PORTB2)); // Outputs
DDRB |= _BV(PORTB1) | _BV(PORTB2); // DO (NOT MOSI) + SCK
#else
SPI.begin();
SPI.setBitOrder(MSBFIRST);
SPI.setDataMode(SPI_MODE0);
#if defined(__AVR__) || defined(CORE_TEENSY)
SPI.setClockDivider(SPI_CLOCK_DIV16); // 1MHz max, else flicker
#else
SPI.setClockDivider((F_CPU + 500000L) / 1000000L);
#endif
#endif
}
uint16_t Adafruit_WS2801::numPixels(void) {
return numLEDs;
}
// Change strand length (see notes with empty constructor, above):
void Adafruit_WS2801::updateLength(uint16_t n) {
if(pixels != NULL) free(pixels); // Free existing data (if any)
// Allocate new data -- note: ALL PIXELS ARE CLEARED
numLEDs = ((pixels = (uint8_t *)calloc(n, 3)) != NULL) ? n : 0;
// 'begun' state does not change -- pins retain prior modes
}
// Change RGB data order (see notes with empty constructor, above):
void Adafruit_WS2801::updateOrder(uint8_t order) {
rgb_order = order;
// Existing LED data, if any, is NOT reformatted to new data order.
// Calling function should clear or fill pixel data anew.
}
void Adafruit_WS2801::show(void) {
uint16_t i, nl3 = numLEDs * 3; // 3 bytes per LED
uint8_t bit;
// Write 24 bits per pixel:
if(hardwareSPI) {
for(i=0; i<nl3; i++) spi_out(pixels[i]);
} else {
for(i=0; i<nl3; i++ ) {
for(bit=0x80; bit; bit >>= 1) {
#ifdef __AVR__
if(pixels[i] & bit) *dataport |= datapinmask;
else *dataport &= ~datapinmask;
*clkport |= clkpinmask;
*clkport &= ~clkpinmask;
#else
if(pixels[i] & bit) digitalWrite(datapin, HIGH);
else digitalWrite(datapin, LOW);
digitalWrite(clkpin, HIGH);
digitalWrite(clkpin, LOW);
#endif
}
}
}
delay(1); // Data is latched by holding clock pin low for 1 millisecond
}
// Set pixel color from separate 8-bit R, G, B components:
void Adafruit_WS2801::setPixelColor(uint16_t n, uint8_t r, uint8_t g, uint8_t b) {
if(n < numLEDs) { // Arrays are 0-indexed, thus NOT '<='
uint8_t *p = &pixels[n * 3];
// See notes later regarding color order
if(rgb_order == WS2801_RGB) {
*p++ = r;
*p++ = g;
} else {
*p++ = g;
*p++ = r;
}
*p++ = b;
}
}
// Set pixel color from separate 8-bit R, G, B components using x,y coordinate system:
void Adafruit_WS2801::setPixelColor(uint16_t x, uint16_t y, uint8_t r, uint8_t g, uint8_t b) {
boolean evenRow = ((y % 2) == 0);
// calculate x offset first
uint16_t offset = x % width;
if (!evenRow) {
offset = (width-1) - offset;
}
// add y offset
offset += y * width;
setPixelColor(offset, r, g, b);
}
// Set pixel color from 'packed' 32-bit RGB value:
void Adafruit_WS2801::setPixelColor(uint16_t n, uint32_t c) {
if(n < numLEDs) { // Arrays are 0-indexed, thus NOT '<='
uint8_t *p = &pixels[n * 3];
// To keep the show() loop as simple & fast as possible, the
// internal color representation is native to different pixel
// types. For compatibility with existing code, 'packed' RGB
// values passed in or out are always 0xRRGGBB order.
if(rgb_order == WS2801_RGB) {
*p++ = c >> 16; // Red
*p++ = c >> 8; // Green
} else {
*p++ = c >> 8; // Green
*p++ = c >> 16; // Red
}
*p++ = c; // Blue
}
}
// Set pixel color from 'packed' 32-bit RGB value using x,y coordinate system:
void Adafruit_WS2801::setPixelColor(uint16_t x, uint16_t y, uint32_t c) {
boolean evenRow = ((y % 2) == 0);
// calculate x offset first
uint16_t offset = x % width;
if (!evenRow) {
offset = (width-1) - offset;
}
// add y offset
offset += y * width;
setPixelColor(offset, c);
}
// Query color from previously-set pixel (returns packed 32-bit RGB value)
uint32_t Adafruit_WS2801::getPixelColor(uint16_t n) {
if(n < numLEDs) {
uint16_t ofs = n * 3;
// To keep the show() loop as simple & fast as possible, the
// internal color representation is native to different pixel
// types. For compatibility with existing code, 'packed' RGB
// values passed in or out are always 0xRRGGBB order.
return (rgb_order == WS2801_RGB) ?
((uint32_t)pixels[ofs] << 16) | ((uint16_t) pixels[ofs + 1] << 8) | pixels[ofs + 2] :
(pixels[ofs] << 8) | ((uint32_t)pixels[ofs + 1] << 16) | pixels[ofs + 2];
}
return 0; // Pixel # is out of bounds
}