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Adafruit_NeoPixel.cpp
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Adafruit_NeoPixel.cpp
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/*-------------------------------------------------------------------------
Arduino library to control a wide variety of WS2811- and WS2812-based RGB
LED devices such as Adafruit FLORA RGB Smart Pixels and NeoPixel strips.
Currently handles 400 and 800 KHz bitstreams on 8, 12 and 16 MHz ATmega
MCUs, with LEDs wired for various color orders. 8 MHz MCUs provide
output on PORTB and PORTD, while 16 MHz chips can handle most output pins
(possible exception with upper PORT registers on the Arduino Mega).
Written by Phil Burgess / Paint Your Dragon for Adafruit Industries,
contributions by PJRC, Michael Miller and other members of the open
source community.
Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing products
from Adafruit!
-------------------------------------------------------------------------
This file is part of the Adafruit NeoPixel library.
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.
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/>.
-------------------------------------------------------------------------*/
#include "Adafruit_NeoPixel.h"
// Constructor when length, pin and type are known at compile-time:
Adafruit_NeoPixel::Adafruit_NeoPixel(uint16_t n, uint8_t p, neoPixelType t) :
brightness(0), pixels(NULL), endTime(0), begun(false)
{
updateType(t);
updateLength(n);
setPin(p);
}
// 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 updateType(),
// updateLength(), etc. to establish the strand type, length and pin number!
Adafruit_NeoPixel::Adafruit_NeoPixel() :
pin(-1), brightness(0), pixels(NULL), endTime(0), begun(false),
numLEDs(0), numBytes(0), rOffset(1), gOffset(0), bOffset(2), wOffset(1)
#ifdef NEO_KHZ400
, is800KHz(true)
#endif
{
}
Adafruit_NeoPixel::~Adafruit_NeoPixel() {
if(pixels) free(pixels);
if(pin >= 0) pinMode(pin, INPUT);
}
void Adafruit_NeoPixel::begin(void) {
if(pin >= 0) {
pinMode(pin, OUTPUT);
digitalWrite(pin, LOW);
}
begun = true;
}
void Adafruit_NeoPixel::updateLength(uint16_t n) {
if(pixels) free(pixels); // Free existing data (if any)
// Allocate new data -- note: ALL PIXELS ARE CLEARED
numBytes = n * ((wOffset == rOffset) ? 3 : 4);
if((pixels = (uint8_t *)malloc(numBytes))) {
memset(pixels, 0, numBytes);
numLEDs = n;
} else {
numLEDs = numBytes = 0;
}
}
void Adafruit_NeoPixel::updateType(neoPixelType t) {
boolean oldThreeBytesPerPixel = (wOffset == rOffset); // false if RGBW
wOffset = (t >> 6) & 0b11; // See notes in header file
rOffset = (t >> 4) & 0b11; // regarding R/G/B/W offsets
gOffset = (t >> 2) & 0b11;
bOffset = t & 0b11;
#ifdef NEO_KHZ400
is800KHz = (t < 256); // 400 KHz flag is 1<<8
#endif
// If bytes-per-pixel has changed (and pixel data was previously
// allocated), re-allocate to new size. Will clear any data.
if(pixels) {
boolean newThreeBytesPerPixel = (wOffset == rOffset);
if(newThreeBytesPerPixel != oldThreeBytesPerPixel) updateLength(numLEDs);
}
}
#ifdef ESP8266
// ESP8266 show() is external to enforce ICACHE_RAM_ATTR execution
extern "C" void ICACHE_RAM_ATTR espShow(
uint8_t pin, uint8_t *pixels, uint32_t numBytes, uint8_t type);
#endif // ESP8266
void Adafruit_NeoPixel::show(void) {
if(!pixels) return;
// Data latch = 50+ microsecond pause in the output stream. Rather than
// put a delay at the end of the function, the ending time is noted and
// the function will simply hold off (if needed) on issuing the
// subsequent round of data until the latch time has elapsed. This
// allows the mainline code to start generating the next frame of data
// rather than stalling for the latch.
while(!canShow());
// endTime is a private member (rather than global var) so that mutliple
// instances on different pins can be quickly issued in succession (each
// instance doesn't delay the next).
// In order to make this code runtime-configurable to work with any pin,
// SBI/CBI instructions are eschewed in favor of full PORT writes via the
// OUT or ST instructions. It relies on two facts: that peripheral
// functions (such as PWM) take precedence on output pins, so our PORT-
// wide writes won't interfere, and that interrupts are globally disabled
// while data is being issued to the LEDs, so no other code will be
// accessing the PORT. The code takes an initial 'snapshot' of the PORT
// state, computes 'pin high' and 'pin low' values, and writes these back
// to the PORT register as needed.
noInterrupts(); // Need 100% focus on instruction timing
#ifdef __AVR__
// AVR MCUs -- ATmega & ATtiny (no XMEGA) ---------------------------------
volatile uint16_t
i = numBytes; // Loop counter
volatile uint8_t
*ptr = pixels, // Pointer to next byte
b = *ptr++, // Current byte value
hi, // PORT w/output bit set high
lo; // PORT w/output bit set low
// Hand-tuned assembly code issues data to the LED drivers at a specific
// rate. There's separate code for different CPU speeds (8, 12, 16 MHz)
// for both the WS2811 (400 KHz) and WS2812 (800 KHz) drivers. The
// datastream timing for the LED drivers allows a little wiggle room each
// way (listed in the datasheets), so the conditions for compiling each
// case are set up for a range of frequencies rather than just the exact
// 8, 12 or 16 MHz values, permitting use with some close-but-not-spot-on
// devices (e.g. 16.5 MHz DigiSpark). The ranges were arrived at based
// on the datasheet figures and have not been extensively tested outside
// the canonical 8/12/16 MHz speeds; there's no guarantee these will work
// close to the extremes (or possibly they could be pushed further).
// Keep in mind only one CPU speed case actually gets compiled; the
// resulting program isn't as massive as it might look from source here.
// 8 MHz(ish) AVR ---------------------------------------------------------
#if (F_CPU >= 7400000UL) && (F_CPU <= 9500000UL)
#ifdef NEO_KHZ400 // 800 KHz check needed only if 400 KHz support enabled
if(is800KHz) {
#endif
volatile uint8_t n1, n2 = 0; // First, next bits out
// Squeezing an 800 KHz stream out of an 8 MHz chip requires code
// specific to each PORT register. At present this is only written
// to work with pins on PORTD or PORTB, the most likely use case --
// this covers all the pins on the Adafruit Flora and the bulk of
// digital pins on the Arduino Pro 8 MHz (keep in mind, this code
// doesn't even get compiled for 16 MHz boards like the Uno, Mega,
// Leonardo, etc., so don't bother extending this out of hand).
// Additional PORTs could be added if you really need them, just
// duplicate the else and loop and change the PORT. Each add'l
// PORT will require about 150(ish) bytes of program space.
// 10 instruction clocks per bit: HHxxxxxLLL
// OUT instructions: ^ ^ ^ (T=0,2,7)
#ifdef PORTD // PORTD isn't present on ATtiny85, etc.
if(port == &PORTD) {
hi = PORTD | pinMask;
lo = PORTD & ~pinMask;
n1 = lo;
if(b & 0x80) n1 = hi;
// Dirty trick: RJMPs proceeding to the next instruction are used
// to delay two clock cycles in one instruction word (rather than
// using two NOPs). This was necessary in order to squeeze the
// loop down to exactly 64 words -- the maximum possible for a
// relative branch.
asm volatile(
"headD:" "\n\t" // Clk Pseudocode
// Bit 7:
"out %[port] , %[hi]" "\n\t" // 1 PORT = hi
"mov %[n2] , %[lo]" "\n\t" // 1 n2 = lo
"out %[port] , %[n1]" "\n\t" // 1 PORT = n1
"rjmp .+0" "\n\t" // 2 nop nop
"sbrc %[byte] , 6" "\n\t" // 1-2 if(b & 0x40)
"mov %[n2] , %[hi]" "\n\t" // 0-1 n2 = hi
"out %[port] , %[lo]" "\n\t" // 1 PORT = lo
"rjmp .+0" "\n\t" // 2 nop nop
// Bit 6:
"out %[port] , %[hi]" "\n\t" // 1 PORT = hi
"mov %[n1] , %[lo]" "\n\t" // 1 n1 = lo
"out %[port] , %[n2]" "\n\t" // 1 PORT = n2
"rjmp .+0" "\n\t" // 2 nop nop
"sbrc %[byte] , 5" "\n\t" // 1-2 if(b & 0x20)
"mov %[n1] , %[hi]" "\n\t" // 0-1 n1 = hi
"out %[port] , %[lo]" "\n\t" // 1 PORT = lo
"rjmp .+0" "\n\t" // 2 nop nop
// Bit 5:
"out %[port] , %[hi]" "\n\t" // 1 PORT = hi
"mov %[n2] , %[lo]" "\n\t" // 1 n2 = lo
"out %[port] , %[n1]" "\n\t" // 1 PORT = n1
"rjmp .+0" "\n\t" // 2 nop nop
"sbrc %[byte] , 4" "\n\t" // 1-2 if(b & 0x10)
"mov %[n2] , %[hi]" "\n\t" // 0-1 n2 = hi
"out %[port] , %[lo]" "\n\t" // 1 PORT = lo
"rjmp .+0" "\n\t" // 2 nop nop
// Bit 4:
"out %[port] , %[hi]" "\n\t" // 1 PORT = hi
"mov %[n1] , %[lo]" "\n\t" // 1 n1 = lo
"out %[port] , %[n2]" "\n\t" // 1 PORT = n2
"rjmp .+0" "\n\t" // 2 nop nop
"sbrc %[byte] , 3" "\n\t" // 1-2 if(b & 0x08)
"mov %[n1] , %[hi]" "\n\t" // 0-1 n1 = hi
"out %[port] , %[lo]" "\n\t" // 1 PORT = lo
"rjmp .+0" "\n\t" // 2 nop nop
// Bit 3:
"out %[port] , %[hi]" "\n\t" // 1 PORT = hi
"mov %[n2] , %[lo]" "\n\t" // 1 n2 = lo
"out %[port] , %[n1]" "\n\t" // 1 PORT = n1
"rjmp .+0" "\n\t" // 2 nop nop
"sbrc %[byte] , 2" "\n\t" // 1-2 if(b & 0x04)
"mov %[n2] , %[hi]" "\n\t" // 0-1 n2 = hi
"out %[port] , %[lo]" "\n\t" // 1 PORT = lo
"rjmp .+0" "\n\t" // 2 nop nop
// Bit 2:
"out %[port] , %[hi]" "\n\t" // 1 PORT = hi
"mov %[n1] , %[lo]" "\n\t" // 1 n1 = lo
"out %[port] , %[n2]" "\n\t" // 1 PORT = n2
"rjmp .+0" "\n\t" // 2 nop nop
"sbrc %[byte] , 1" "\n\t" // 1-2 if(b & 0x02)
"mov %[n1] , %[hi]" "\n\t" // 0-1 n1 = hi
"out %[port] , %[lo]" "\n\t" // 1 PORT = lo
"rjmp .+0" "\n\t" // 2 nop nop
// Bit 1:
"out %[port] , %[hi]" "\n\t" // 1 PORT = hi
"mov %[n2] , %[lo]" "\n\t" // 1 n2 = lo
"out %[port] , %[n1]" "\n\t" // 1 PORT = n1
"rjmp .+0" "\n\t" // 2 nop nop
"sbrc %[byte] , 0" "\n\t" // 1-2 if(b & 0x01)
"mov %[n2] , %[hi]" "\n\t" // 0-1 n2 = hi
"out %[port] , %[lo]" "\n\t" // 1 PORT = lo
"sbiw %[count], 1" "\n\t" // 2 i-- (don't act on Z flag yet)
// Bit 0:
"out %[port] , %[hi]" "\n\t" // 1 PORT = hi
"mov %[n1] , %[lo]" "\n\t" // 1 n1 = lo
"out %[port] , %[n2]" "\n\t" // 1 PORT = n2
"ld %[byte] , %a[ptr]+" "\n\t" // 2 b = *ptr++
"sbrc %[byte] , 7" "\n\t" // 1-2 if(b & 0x80)
"mov %[n1] , %[hi]" "\n\t" // 0-1 n1 = hi
"out %[port] , %[lo]" "\n\t" // 1 PORT = lo
"brne headD" "\n" // 2 while(i) (Z flag set above)
: [byte] "+r" (b),
[n1] "+r" (n1),
[n2] "+r" (n2),
[count] "+w" (i)
: [port] "I" (_SFR_IO_ADDR(PORTD)),
[ptr] "e" (ptr),
[hi] "r" (hi),
[lo] "r" (lo));
} else if(port == &PORTB) {
#endif // PORTD
// Same as above, just switched to PORTB and stripped of comments.
hi = PORTB | pinMask;
lo = PORTB & ~pinMask;
n1 = lo;
if(b & 0x80) n1 = hi;
asm volatile(
"headB:" "\n\t"
"out %[port] , %[hi]" "\n\t"
"mov %[n2] , %[lo]" "\n\t"
"out %[port] , %[n1]" "\n\t"
"rjmp .+0" "\n\t"
"sbrc %[byte] , 6" "\n\t"
"mov %[n2] , %[hi]" "\n\t"
"out %[port] , %[lo]" "\n\t"
"rjmp .+0" "\n\t"
"out %[port] , %[hi]" "\n\t"
"mov %[n1] , %[lo]" "\n\t"
"out %[port] , %[n2]" "\n\t"
"rjmp .+0" "\n\t"
"sbrc %[byte] , 5" "\n\t"
"mov %[n1] , %[hi]" "\n\t"
"out %[port] , %[lo]" "\n\t"
"rjmp .+0" "\n\t"
"out %[port] , %[hi]" "\n\t"
"mov %[n2] , %[lo]" "\n\t"
"out %[port] , %[n1]" "\n\t"
"rjmp .+0" "\n\t"
"sbrc %[byte] , 4" "\n\t"
"mov %[n2] , %[hi]" "\n\t"
"out %[port] , %[lo]" "\n\t"
"rjmp .+0" "\n\t"
"out %[port] , %[hi]" "\n\t"
"mov %[n1] , %[lo]" "\n\t"
"out %[port] , %[n2]" "\n\t"
"rjmp .+0" "\n\t"
"sbrc %[byte] , 3" "\n\t"
"mov %[n1] , %[hi]" "\n\t"
"out %[port] , %[lo]" "\n\t"
"rjmp .+0" "\n\t"
"out %[port] , %[hi]" "\n\t"
"mov %[n2] , %[lo]" "\n\t"
"out %[port] , %[n1]" "\n\t"
"rjmp .+0" "\n\t"
"sbrc %[byte] , 2" "\n\t"
"mov %[n2] , %[hi]" "\n\t"
"out %[port] , %[lo]" "\n\t"
"rjmp .+0" "\n\t"
"out %[port] , %[hi]" "\n\t"
"mov %[n1] , %[lo]" "\n\t"
"out %[port] , %[n2]" "\n\t"
"rjmp .+0" "\n\t"
"sbrc %[byte] , 1" "\n\t"
"mov %[n1] , %[hi]" "\n\t"
"out %[port] , %[lo]" "\n\t"
"rjmp .+0" "\n\t"
"out %[port] , %[hi]" "\n\t"
"mov %[n2] , %[lo]" "\n\t"
"out %[port] , %[n1]" "\n\t"
"rjmp .+0" "\n\t"
"sbrc %[byte] , 0" "\n\t"
"mov %[n2] , %[hi]" "\n\t"
"out %[port] , %[lo]" "\n\t"
"sbiw %[count], 1" "\n\t"
"out %[port] , %[hi]" "\n\t"
"mov %[n1] , %[lo]" "\n\t"
"out %[port] , %[n2]" "\n\t"
"ld %[byte] , %a[ptr]+" "\n\t"
"sbrc %[byte] , 7" "\n\t"
"mov %[n1] , %[hi]" "\n\t"
"out %[port] , %[lo]" "\n\t"
"brne headB" "\n"
: [byte] "+r" (b), [n1] "+r" (n1), [n2] "+r" (n2), [count] "+w" (i)
: [port] "I" (_SFR_IO_ADDR(PORTB)), [ptr] "e" (ptr), [hi] "r" (hi),
[lo] "r" (lo));
#ifdef PORTD
} // endif PORTB
#endif
#ifdef NEO_KHZ400
} else { // end 800 KHz, do 400 KHz
// Timing is more relaxed; unrolling the inner loop for each bit is
// not necessary. Still using the peculiar RJMPs as 2X NOPs, not out
// of need but just to trim the code size down a little.
// This 400-KHz-datastream-on-8-MHz-CPU code is not quite identical
// to the 800-on-16 code later -- the hi/lo timing between WS2811 and
// WS2812 is not simply a 2:1 scale!
// 20 inst. clocks per bit: HHHHxxxxxxLLLLLLLLLL
// ST instructions: ^ ^ ^ (T=0,4,10)
volatile uint8_t next, bit;
hi = *port | pinMask;
lo = *port & ~pinMask;
next = lo;
bit = 8;
asm volatile(
"head20:" "\n\t" // Clk Pseudocode (T = 0)
"st %a[port], %[hi]" "\n\t" // 2 PORT = hi (T = 2)
"sbrc %[byte] , 7" "\n\t" // 1-2 if(b & 128)
"mov %[next], %[hi]" "\n\t" // 0-1 next = hi (T = 4)
"st %a[port], %[next]" "\n\t" // 2 PORT = next (T = 6)
"mov %[next] , %[lo]" "\n\t" // 1 next = lo (T = 7)
"dec %[bit]" "\n\t" // 1 bit-- (T = 8)
"breq nextbyte20" "\n\t" // 1-2 if(bit == 0)
"rol %[byte]" "\n\t" // 1 b <<= 1 (T = 10)
"st %a[port], %[lo]" "\n\t" // 2 PORT = lo (T = 12)
"rjmp .+0" "\n\t" // 2 nop nop (T = 14)
"rjmp .+0" "\n\t" // 2 nop nop (T = 16)
"rjmp .+0" "\n\t" // 2 nop nop (T = 18)
"rjmp head20" "\n\t" // 2 -> head20 (next bit out)
"nextbyte20:" "\n\t" // (T = 10)
"st %a[port], %[lo]" "\n\t" // 2 PORT = lo (T = 12)
"nop" "\n\t" // 1 nop (T = 13)
"ldi %[bit] , 8" "\n\t" // 1 bit = 8 (T = 14)
"ld %[byte] , %a[ptr]+" "\n\t" // 2 b = *ptr++ (T = 16)
"sbiw %[count], 1" "\n\t" // 2 i-- (T = 18)
"brne head20" "\n" // 2 if(i != 0) -> (next byte)
: [port] "+e" (port),
[byte] "+r" (b),
[bit] "+r" (bit),
[next] "+r" (next),
[count] "+w" (i)
: [hi] "r" (hi),
[lo] "r" (lo),
[ptr] "e" (ptr));
}
#endif // NEO_KHZ400
// 12 MHz(ish) AVR --------------------------------------------------------
#elif (F_CPU >= 11100000UL) && (F_CPU <= 14300000UL)
#ifdef NEO_KHZ400 // 800 KHz check needed only if 400 KHz support enabled
if(is800KHz) {
#endif
// In the 12 MHz case, an optimized 800 KHz datastream (no dead time
// between bytes) requires a PORT-specific loop similar to the 8 MHz
// code (but a little more relaxed in this case).
// 15 instruction clocks per bit: HHHHxxxxxxLLLLL
// OUT instructions: ^ ^ ^ (T=0,4,10)
volatile uint8_t next;
#ifdef PORTD
if(port == &PORTD) {
hi = PORTD | pinMask;
lo = PORTD & ~pinMask;
next = lo;
if(b & 0x80) next = hi;
// Don't "optimize" the OUT calls into the bitTime subroutine;
// we're exploiting the RCALL and RET as 3- and 4-cycle NOPs!
asm volatile(
"headD:" "\n\t" // (T = 0)
"out %[port], %[hi]" "\n\t" // (T = 1)
"rcall bitTimeD" "\n\t" // Bit 7 (T = 15)
"out %[port], %[hi]" "\n\t"
"rcall bitTimeD" "\n\t" // Bit 6
"out %[port], %[hi]" "\n\t"
"rcall bitTimeD" "\n\t" // Bit 5
"out %[port], %[hi]" "\n\t"
"rcall bitTimeD" "\n\t" // Bit 4
"out %[port], %[hi]" "\n\t"
"rcall bitTimeD" "\n\t" // Bit 3
"out %[port], %[hi]" "\n\t"
"rcall bitTimeD" "\n\t" // Bit 2
"out %[port], %[hi]" "\n\t"
"rcall bitTimeD" "\n\t" // Bit 1
// Bit 0:
"out %[port] , %[hi]" "\n\t" // 1 PORT = hi (T = 1)
"rjmp .+0" "\n\t" // 2 nop nop (T = 3)
"ld %[byte] , %a[ptr]+" "\n\t" // 2 b = *ptr++ (T = 5)
"out %[port] , %[next]" "\n\t" // 1 PORT = next (T = 6)
"mov %[next] , %[lo]" "\n\t" // 1 next = lo (T = 7)
"sbrc %[byte] , 7" "\n\t" // 1-2 if(b & 0x80) (T = 8)
"mov %[next] , %[hi]" "\n\t" // 0-1 next = hi (T = 9)
"nop" "\n\t" // 1 (T = 10)
"out %[port] , %[lo]" "\n\t" // 1 PORT = lo (T = 11)
"sbiw %[count], 1" "\n\t" // 2 i-- (T = 13)
"brne headD" "\n\t" // 2 if(i != 0) -> (next byte)
"rjmp doneD" "\n\t"
"bitTimeD:" "\n\t" // nop nop nop (T = 4)
"out %[port], %[next]" "\n\t" // 1 PORT = next (T = 5)
"mov %[next], %[lo]" "\n\t" // 1 next = lo (T = 6)
"rol %[byte]" "\n\t" // 1 b <<= 1 (T = 7)
"sbrc %[byte], 7" "\n\t" // 1-2 if(b & 0x80) (T = 8)
"mov %[next], %[hi]" "\n\t" // 0-1 next = hi (T = 9)
"nop" "\n\t" // 1 (T = 10)
"out %[port], %[lo]" "\n\t" // 1 PORT = lo (T = 11)
"ret" "\n\t" // 4 nop nop nop nop (T = 15)
"doneD:" "\n"
: [byte] "+r" (b),
[next] "+r" (next),
[count] "+w" (i)
: [port] "I" (_SFR_IO_ADDR(PORTD)),
[ptr] "e" (ptr),
[hi] "r" (hi),
[lo] "r" (lo));
} else if(port == &PORTB) {
#endif // PORTD
hi = PORTB | pinMask;
lo = PORTB & ~pinMask;
next = lo;
if(b & 0x80) next = hi;
// Same as above, just set for PORTB & stripped of comments
asm volatile(
"headB:" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeB" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeB" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeB" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeB" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeB" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeB" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeB" "\n\t"
"out %[port] , %[hi]" "\n\t"
"rjmp .+0" "\n\t"
"ld %[byte] , %a[ptr]+" "\n\t"
"out %[port] , %[next]" "\n\t"
"mov %[next] , %[lo]" "\n\t"
"sbrc %[byte] , 7" "\n\t"
"mov %[next] , %[hi]" "\n\t"
"nop" "\n\t"
"out %[port] , %[lo]" "\n\t"
"sbiw %[count], 1" "\n\t"
"brne headB" "\n\t"
"rjmp doneB" "\n\t"
"bitTimeB:" "\n\t"
"out %[port], %[next]" "\n\t"
"mov %[next], %[lo]" "\n\t"
"rol %[byte]" "\n\t"
"sbrc %[byte], 7" "\n\t"
"mov %[next], %[hi]" "\n\t"
"nop" "\n\t"
"out %[port], %[lo]" "\n\t"
"ret" "\n\t"
"doneB:" "\n"
: [byte] "+r" (b), [next] "+r" (next), [count] "+w" (i)
: [port] "I" (_SFR_IO_ADDR(PORTB)), [ptr] "e" (ptr), [hi] "r" (hi),
[lo] "r" (lo));
#ifdef PORTD
}
#endif
#ifdef NEO_KHZ400
} else { // 400 KHz
// 30 instruction clocks per bit: HHHHHHxxxxxxxxxLLLLLLLLLLLLLLL
// ST instructions: ^ ^ ^ (T=0,6,15)
volatile uint8_t next, bit;
hi = *port | pinMask;
lo = *port & ~pinMask;
next = lo;
bit = 8;
asm volatile(
"head30:" "\n\t" // Clk Pseudocode (T = 0)
"st %a[port], %[hi]" "\n\t" // 2 PORT = hi (T = 2)
"sbrc %[byte] , 7" "\n\t" // 1-2 if(b & 128)
"mov %[next], %[hi]" "\n\t" // 0-1 next = hi (T = 4)
"rjmp .+0" "\n\t" // 2 nop nop (T = 6)
"st %a[port], %[next]" "\n\t" // 2 PORT = next (T = 8)
"rjmp .+0" "\n\t" // 2 nop nop (T = 10)
"rjmp .+0" "\n\t" // 2 nop nop (T = 12)
"rjmp .+0" "\n\t" // 2 nop nop (T = 14)
"nop" "\n\t" // 1 nop (T = 15)
"st %a[port], %[lo]" "\n\t" // 2 PORT = lo (T = 17)
"rjmp .+0" "\n\t" // 2 nop nop (T = 19)
"dec %[bit]" "\n\t" // 1 bit-- (T = 20)
"breq nextbyte30" "\n\t" // 1-2 if(bit == 0)
"rol %[byte]" "\n\t" // 1 b <<= 1 (T = 22)
"rjmp .+0" "\n\t" // 2 nop nop (T = 24)
"rjmp .+0" "\n\t" // 2 nop nop (T = 26)
"rjmp .+0" "\n\t" // 2 nop nop (T = 28)
"rjmp head30" "\n\t" // 2 -> head30 (next bit out)
"nextbyte30:" "\n\t" // (T = 22)
"nop" "\n\t" // 1 nop (T = 23)
"ldi %[bit] , 8" "\n\t" // 1 bit = 8 (T = 24)
"ld %[byte] , %a[ptr]+" "\n\t" // 2 b = *ptr++ (T = 26)
"sbiw %[count], 1" "\n\t" // 2 i-- (T = 28)
"brne head30" "\n" // 1-2 if(i != 0) -> (next byte)
: [port] "+e" (port),
[byte] "+r" (b),
[bit] "+r" (bit),
[next] "+r" (next),
[count] "+w" (i)
: [hi] "r" (hi),
[lo] "r" (lo),
[ptr] "e" (ptr));
}
#endif // NEO_KHZ400
// 16 MHz(ish) AVR --------------------------------------------------------
#elif (F_CPU >= 15400000UL) && (F_CPU <= 19000000L)
#ifdef NEO_KHZ400 // 800 KHz check needed only if 400 KHz support enabled
if(is800KHz) {
#endif
// WS2811 and WS2812 have different hi/lo duty cycles; this is
// similar but NOT an exact copy of the prior 400-on-8 code.
// 20 inst. clocks per bit: HHHHHxxxxxxxxLLLLLLL
// ST instructions: ^ ^ ^ (T=0,5,13)
volatile uint8_t next, bit;
hi = *port | pinMask;
lo = *port & ~pinMask;
next = lo;
bit = 8;
asm volatile(
"head20:" "\n\t" // Clk Pseudocode (T = 0)
"st %a[port], %[hi]" "\n\t" // 2 PORT = hi (T = 2)
"sbrc %[byte], 7" "\n\t" // 1-2 if(b & 128)
"mov %[next], %[hi]" "\n\t" // 0-1 next = hi (T = 4)
"dec %[bit]" "\n\t" // 1 bit-- (T = 5)
"st %a[port], %[next]" "\n\t" // 2 PORT = next (T = 7)
"mov %[next] , %[lo]" "\n\t" // 1 next = lo (T = 8)
"breq nextbyte20" "\n\t" // 1-2 if(bit == 0) (from dec above)
"rol %[byte]" "\n\t" // 1 b <<= 1 (T = 10)
"rjmp .+0" "\n\t" // 2 nop nop (T = 12)
"nop" "\n\t" // 1 nop (T = 13)
"st %a[port], %[lo]" "\n\t" // 2 PORT = lo (T = 15)
"nop" "\n\t" // 1 nop (T = 16)
"rjmp .+0" "\n\t" // 2 nop nop (T = 18)
"rjmp head20" "\n\t" // 2 -> head20 (next bit out)
"nextbyte20:" "\n\t" // (T = 10)
"ldi %[bit] , 8" "\n\t" // 1 bit = 8 (T = 11)
"ld %[byte] , %a[ptr]+" "\n\t" // 2 b = *ptr++ (T = 13)
"st %a[port], %[lo]" "\n\t" // 2 PORT = lo (T = 15)
"nop" "\n\t" // 1 nop (T = 16)
"sbiw %[count], 1" "\n\t" // 2 i-- (T = 18)
"brne head20" "\n" // 2 if(i != 0) -> (next byte)
: [port] "+e" (port),
[byte] "+r" (b),
[bit] "+r" (bit),
[next] "+r" (next),
[count] "+w" (i)
: [ptr] "e" (ptr),
[hi] "r" (hi),
[lo] "r" (lo));
#ifdef NEO_KHZ400
} else { // 400 KHz
// The 400 KHz clock on 16 MHz MCU is the most 'relaxed' version.
// 40 inst. clocks per bit: HHHHHHHHxxxxxxxxxxxxLLLLLLLLLLLLLLLLLLLL
// ST instructions: ^ ^ ^ (T=0,8,20)
volatile uint8_t next, bit;
hi = *port | pinMask;
lo = *port & ~pinMask;
next = lo;
bit = 8;
asm volatile(
"head40:" "\n\t" // Clk Pseudocode (T = 0)
"st %a[port], %[hi]" "\n\t" // 2 PORT = hi (T = 2)
"sbrc %[byte] , 7" "\n\t" // 1-2 if(b & 128)
"mov %[next] , %[hi]" "\n\t" // 0-1 next = hi (T = 4)
"rjmp .+0" "\n\t" // 2 nop nop (T = 6)
"rjmp .+0" "\n\t" // 2 nop nop (T = 8)
"st %a[port], %[next]" "\n\t" // 2 PORT = next (T = 10)
"rjmp .+0" "\n\t" // 2 nop nop (T = 12)
"rjmp .+0" "\n\t" // 2 nop nop (T = 14)
"rjmp .+0" "\n\t" // 2 nop nop (T = 16)
"rjmp .+0" "\n\t" // 2 nop nop (T = 18)
"rjmp .+0" "\n\t" // 2 nop nop (T = 20)
"st %a[port], %[lo]" "\n\t" // 2 PORT = lo (T = 22)
"nop" "\n\t" // 1 nop (T = 23)
"mov %[next] , %[lo]" "\n\t" // 1 next = lo (T = 24)
"dec %[bit]" "\n\t" // 1 bit-- (T = 25)
"breq nextbyte40" "\n\t" // 1-2 if(bit == 0)
"rol %[byte]" "\n\t" // 1 b <<= 1 (T = 27)
"nop" "\n\t" // 1 nop (T = 28)
"rjmp .+0" "\n\t" // 2 nop nop (T = 30)
"rjmp .+0" "\n\t" // 2 nop nop (T = 32)
"rjmp .+0" "\n\t" // 2 nop nop (T = 34)
"rjmp .+0" "\n\t" // 2 nop nop (T = 36)
"rjmp .+0" "\n\t" // 2 nop nop (T = 38)
"rjmp head40" "\n\t" // 2 -> head40 (next bit out)
"nextbyte40:" "\n\t" // (T = 27)
"ldi %[bit] , 8" "\n\t" // 1 bit = 8 (T = 28)
"ld %[byte] , %a[ptr]+" "\n\t" // 2 b = *ptr++ (T = 30)
"rjmp .+0" "\n\t" // 2 nop nop (T = 32)
"st %a[port], %[lo]" "\n\t" // 2 PORT = lo (T = 34)
"rjmp .+0" "\n\t" // 2 nop nop (T = 36)
"sbiw %[count], 1" "\n\t" // 2 i-- (T = 38)
"brne head40" "\n" // 1-2 if(i != 0) -> (next byte)
: [port] "+e" (port),
[byte] "+r" (b),
[bit] "+r" (bit),
[next] "+r" (next),
[count] "+w" (i)
: [ptr] "e" (ptr),
[hi] "r" (hi),
[lo] "r" (lo));
}
#endif // NEO_KHZ400
#else
#error "CPU SPEED NOT SUPPORTED"
#endif // end F_CPU ifdefs on __AVR__
// END AVR ----------------------------------------------------------------
#elif defined(__arm__)
// ARM MCUs -- Teensy 3.0, 3.1, LC, Arduino Due ---------------------------
#if defined(__MK20DX128__) || defined(__MK20DX256__) // Teensy 3.0 & 3.1
#define CYCLES_800_T0H (F_CPU / 4000000)
#define CYCLES_800_T1H (F_CPU / 1250000)
#define CYCLES_800 (F_CPU / 800000)
#define CYCLES_400_T0H (F_CPU / 2000000)
#define CYCLES_400_T1H (F_CPU / 833333)
#define CYCLES_400 (F_CPU / 400000)
uint8_t *p = pixels,
*end = p + numBytes, pix, mask;
volatile uint8_t *set = portSetRegister(pin),
*clr = portClearRegister(pin);
uint32_t cyc;
ARM_DEMCR |= ARM_DEMCR_TRCENA;
ARM_DWT_CTRL |= ARM_DWT_CTRL_CYCCNTENA;
#ifdef NEO_KHZ400 // 800 KHz check needed only if 400 KHz support enabled
if(is800KHz) {
#endif
cyc = ARM_DWT_CYCCNT + CYCLES_800;
while(p < end) {
pix = *p++;
for(mask = 0x80; mask; mask >>= 1) {
while(ARM_DWT_CYCCNT - cyc < CYCLES_800);
cyc = ARM_DWT_CYCCNT;
*set = 1;
if(pix & mask) {
while(ARM_DWT_CYCCNT - cyc < CYCLES_800_T1H);
} else {
while(ARM_DWT_CYCCNT - cyc < CYCLES_800_T0H);
}
*clr = 1;
}
}
while(ARM_DWT_CYCCNT - cyc < CYCLES_800);
#ifdef NEO_KHZ400
} else { // 400 kHz bitstream
cyc = ARM_DWT_CYCCNT + CYCLES_400;
while(p < end) {
pix = *p++;
for(mask = 0x80; mask; mask >>= 1) {
while(ARM_DWT_CYCCNT - cyc < CYCLES_400);
cyc = ARM_DWT_CYCCNT;
*set = 1;
if(pix & mask) {
while(ARM_DWT_CYCCNT - cyc < CYCLES_400_T1H);
} else {
while(ARM_DWT_CYCCNT - cyc < CYCLES_400_T0H);
}
*clr = 1;
}
}
while(ARM_DWT_CYCCNT - cyc < CYCLES_400);
}
#endif // NEO_KHZ400
#elif defined(__MKL26Z64__) // Teensy-LC
#if F_CPU == 48000000
uint8_t *p = pixels,
pix, count, dly,
bitmask = digitalPinToBitMask(pin);
volatile uint8_t *reg = portSetRegister(pin);
uint32_t num = numBytes;
asm volatile(
"L%=_begin:" "\n\t"
"ldrb %[pix], [%[p], #0]" "\n\t"
"lsl %[pix], #24" "\n\t"
"movs %[count], #7" "\n\t"
"L%=_loop:" "\n\t"
"lsl %[pix], #1" "\n\t"
"bcs L%=_loop_one" "\n\t"
"L%=_loop_zero:"
"strb %[bitmask], [%[reg], #0]" "\n\t"
"movs %[dly], #4" "\n\t"
"L%=_loop_delay_T0H:" "\n\t"
"sub %[dly], #1" "\n\t"
"bne L%=_loop_delay_T0H" "\n\t"
"strb %[bitmask], [%[reg], #4]" "\n\t"
"movs %[dly], #13" "\n\t"
"L%=_loop_delay_T0L:" "\n\t"
"sub %[dly], #1" "\n\t"
"bne L%=_loop_delay_T0L" "\n\t"
"b L%=_next" "\n\t"
"L%=_loop_one:"
"strb %[bitmask], [%[reg], #0]" "\n\t"
"movs %[dly], #13" "\n\t"
"L%=_loop_delay_T1H:" "\n\t"
"sub %[dly], #1" "\n\t"
"bne L%=_loop_delay_T1H" "\n\t"
"strb %[bitmask], [%[reg], #4]" "\n\t"
"movs %[dly], #4" "\n\t"
"L%=_loop_delay_T1L:" "\n\t"
"sub %[dly], #1" "\n\t"
"bne L%=_loop_delay_T1L" "\n\t"
"nop" "\n\t"
"L%=_next:" "\n\t"
"sub %[count], #1" "\n\t"
"bne L%=_loop" "\n\t"
"lsl %[pix], #1" "\n\t"
"bcs L%=_last_one" "\n\t"
"L%=_last_zero:"
"strb %[bitmask], [%[reg], #0]" "\n\t"
"movs %[dly], #4" "\n\t"
"L%=_last_delay_T0H:" "\n\t"
"sub %[dly], #1" "\n\t"
"bne L%=_last_delay_T0H" "\n\t"
"strb %[bitmask], [%[reg], #4]" "\n\t"
"movs %[dly], #10" "\n\t"
"L%=_last_delay_T0L:" "\n\t"
"sub %[dly], #1" "\n\t"
"bne L%=_last_delay_T0L" "\n\t"
"b L%=_repeat" "\n\t"
"L%=_last_one:"
"strb %[bitmask], [%[reg], #0]" "\n\t"
"movs %[dly], #13" "\n\t"
"L%=_last_delay_T1H:" "\n\t"
"sub %[dly], #1" "\n\t"
"bne L%=_last_delay_T1H" "\n\t"
"strb %[bitmask], [%[reg], #4]" "\n\t"
"movs %[dly], #1" "\n\t"
"L%=_last_delay_T1L:" "\n\t"
"sub %[dly], #1" "\n\t"
"bne L%=_last_delay_T1L" "\n\t"
"nop" "\n\t"
"L%=_repeat:" "\n\t"
"add %[p], #1" "\n\t"
"sub %[num], #1" "\n\t"
"bne L%=_begin" "\n\t"
"L%=_done:" "\n\t"
: [p] "+r" (p),
[pix] "=&r" (pix),
[count] "=&r" (count),
[dly] "=&r" (dly),
[num] "+r" (num)
: [bitmask] "r" (bitmask),
[reg] "r" (reg)
);
#else
#error "Sorry, only 48 MHz is supported, please set Tools > CPU Speed to 48 MHz"
#endif // F_CPU == 48000000
#elif defined(__SAMD21G18A__) // Arduino Zero
// Tried this with a timer/counter, couldn't quite get adequate
// resolution. So yay, you get a load of goofball NOPs...
uint8_t *ptr, *end, p, bitMask, portNum;
uint32_t pinMask;
portNum = g_APinDescription[pin].ulPort;
pinMask = 1ul << g_APinDescription[pin].ulPin;
ptr = pixels;
end = ptr + numBytes;
p = *ptr++;
bitMask = 0x80;
volatile uint32_t *set = &(PORT->Group[portNum].OUTSET.reg),
*clr = &(PORT->Group[portNum].OUTCLR.reg);
#ifdef NEO_KHZ400 // 800 KHz check needed only if 400 KHz support enabled
if(is800KHz) {
#endif
for(;;) {
*set = pinMask;
asm("nop; nop; nop; nop; nop; nop; nop; nop;");
if(p & bitMask) {
asm("nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop; nop;");
*clr = pinMask;
} else {
*clr = pinMask;
asm("nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop; nop;");
}
if(bitMask >>= 1) {
asm("nop; nop; nop; nop; nop; nop; nop; nop; nop;");
} else {
if(ptr >= end) break;
p = *ptr++;
bitMask = 0x80;
}
}
#ifdef NEO_KHZ400
} else { // 400 KHz bitstream
for(;;) {
*set = pinMask;
asm("nop; nop; nop; nop; nop; nop; nop; nop; nop; nop; nop;");
if(p & bitMask) {
asm("nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop;");
*clr = pinMask;
} else {
*clr = pinMask;
asm("nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop;");
}
asm("nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop; nop; nop; nop; nop; nop;"
"nop; nop; nop; nop; nop; nop; nop; nop;");
if(bitMask >>= 1) {
asm("nop; nop; nop; nop; nop; nop; nop;");
} else {
if(ptr >= end) break;
p = *ptr++;
bitMask = 0x80;
}
}
}
#endif
#else // Other ARM architecture -- Presumed Arduino Due
#define SCALE VARIANT_MCK / 2UL / 1000000UL
#define INST (2UL * F_CPU / VARIANT_MCK)
#define TIME_800_0 ((int)(0.40 * SCALE + 0.5) - (5 * INST))
#define TIME_800_1 ((int)(0.80 * SCALE + 0.5) - (5 * INST))
#define PERIOD_800 ((int)(1.25 * SCALE + 0.5) - (5 * INST))
#define TIME_400_0 ((int)(0.50 * SCALE + 0.5) - (5 * INST))
#define TIME_400_1 ((int)(1.20 * SCALE + 0.5) - (5 * INST))
#define PERIOD_400 ((int)(2.50 * SCALE + 0.5) - (5 * INST))
int pinMask, time0, time1, period, t;
Pio *port;
volatile WoReg *portSet, *portClear, *timeValue, *timeReset;
uint8_t *p, *end, pix, mask;
pmc_set_writeprotect(false);
pmc_enable_periph_clk((uint32_t)TC3_IRQn);
TC_Configure(TC1, 0,
TC_CMR_WAVE | TC_CMR_WAVSEL_UP | TC_CMR_TCCLKS_TIMER_CLOCK1);
TC_Start(TC1, 0);
pinMask = g_APinDescription[pin].ulPin; // Don't 'optimize' these into
port = g_APinDescription[pin].pPort; // declarations above. Want to
portSet = &(port->PIO_SODR); // burn a few cycles after
portClear = &(port->PIO_CODR); // starting timer to minimize
timeValue = &(TC1->TC_CHANNEL[0].TC_CV); // the initial 'while'.
timeReset = &(TC1->TC_CHANNEL[0].TC_CCR);
p = pixels;
end = p + numBytes;
pix = *p++;
mask = 0x80;
#ifdef NEO_KHZ400 // 800 KHz check needed only if 400 KHz support enabled
if(is800KHz) {
#endif
time0 = TIME_800_0;
time1 = TIME_800_1;
period = PERIOD_800;
#ifdef NEO_KHZ400
} else { // 400 KHz bitstream
time0 = TIME_400_0;
time1 = TIME_400_1;
period = PERIOD_400;
}
#endif
for(t = time0;; t = time0) {
if(pix & mask) t = time1;
while(*timeValue < period);
*portSet = pinMask;
*timeReset = TC_CCR_CLKEN | TC_CCR_SWTRG;
while(*timeValue < t);
*portClear = pinMask;
if(!(mask >>= 1)) { // This 'inside-out' loop logic utilizes
if(p >= end) break; // idle time to minimize inter-byte delays.