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NeoPixel.cpp
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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. Handles 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 "NeoPixel.h"
// Constructor when length, pin and type are known at compile-time:
NeoPixel::NeoPixel(uint16_t n, uint8_t p, neoPixelType t) :
begun(false), brightness(0), pixels(NULL), endTime(0)
{
updateType(t);
updateLength(n);
setPin(p);
}
NeoPixel::~NeoPixel() {
if(pixels) free(pixels);
if(pin >= 0) pinMode(pin, INPUT);
}
void NeoPixel::begin(void) {
if(pin >= 0) {
pinMode(pin, OUTPUT);
digitalWrite(pin, LOW);
}
begun = true;
}
void 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 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 espUpdate(
uint8_t pin, uint8_t *pixels, uint32_t numBytes, uint8_t type);
#endif // ESP8266
void NeoPixel::update(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.
// 10 instruction clocks per bit: HHxxxxxLLL
// OUT instructions: ^ ^ ^ (T=0,2,7)
// PORTD OUTPUT ----------------------------------------------------
#if defined(PORTD)
#if defined(PORTB) || defined(PORTC) || defined(PORTF)
if(port == &PORTD) {
#endif // defined(PORTB/C/F)
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));
#if defined(PORTB) || defined(PORTC) || defined(PORTF)
} else // other PORT(s)
#endif // defined(PORTB/C/F)
#endif // defined(PORTD)
// PORTB OUTPUT ----------------------------------------------------
#if defined(PORTB)
#if defined(PORTD) || defined(PORTC) || defined(PORTF)
if(port == &PORTB) {
#endif // defined(PORTD/C/F)
// 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));
#if defined(PORTD) || defined(PORTC) || defined(PORTF)
}
#endif
#if defined(PORTC) || defined(PORTF)
else
#endif // defined(PORTC/F)
#endif // defined(PORTB)
// PORTC OUTPUT ----------------------------------------------------
#if defined(PORTC)
#if defined(PORTD) || defined(PORTB) || defined(PORTF)
if(port == &PORTC) {
#endif // defined(PORTD/B/F)
// Same as above, just switched to PORTC and stripped of comments.
hi = PORTC | pinMask;
lo = PORTC & ~pinMask;
n1 = lo;
if(b & 0x80) n1 = hi;
asm volatile(
"headC:" "\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 headC" "\n"
: [byte] "+r" (b), [n1] "+r" (n1), [n2] "+r" (n2), [count] "+w" (i)
: [port] "I" (_SFR_IO_ADDR(PORTC)), [ptr] "e" (ptr), [hi] "r" (hi),
[lo] "r" (lo));
#if defined(PORTD) || defined(PORTB) || defined(PORTF)
}
#endif // defined(PORTD/B/F)
#if defined(PORTF)
else
#endif
#endif // defined(PORTC)
// PORTF OUTPUT ----------------------------------------------------
#if defined(PORTF)
#if defined(PORTD) || defined(PORTB) || defined(PORTC)
if(port == &PORTF) {
#endif // defined(PORTD/B/C)
hi = PORTF | pinMask;
lo = PORTF & ~pinMask;
n1 = lo;
if(b & 0x80) n1 = hi;
asm volatile(
"headF:" "\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 headF" "\n"
: [byte] "+r" (b), [n1] "+r" (n1), [n2] "+r" (n2), [count] "+w" (i)
: [port] "I" (_SFR_IO_ADDR(PORTF)), [ptr] "e" (ptr), [hi] "r" (hi),
[lo] "r" (lo));
#if defined(PORTD) || defined(PORTB) || defined(PORTC)
}
#endif // defined(PORTD/B/C)
#endif // defined(PORTF)
#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;
// PORTD OUTPUT ----------------------------------------------------
#if defined(PORTD)
#if defined(PORTB) || defined(PORTC) || defined(PORTF)
if(port == &PORTD) {
#endif // defined(PORTB/C/F)
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));
#if defined(PORTB) || defined(PORTC) || defined(PORTF)
} else // other PORT(s)
#endif // defined(PORTB/C/F)
#endif // defined(PORTD)
// PORTB OUTPUT ----------------------------------------------------
#if defined(PORTB)
#if defined(PORTD) || defined(PORTC) || defined(PORTF)
if(port == &PORTB) {
#endif // defined(PORTD/C/F)
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));
#if defined(PORTD) || defined(PORTC) || defined(PORTF)
}
#endif
#if defined(PORTC) || defined(PORTF)
else
#endif // defined(PORTC/F)
#endif // defined(PORTB)
// PORTC OUTPUT ----------------------------------------------------
#if defined(PORTC)
#if defined(PORTD) || defined(PORTB) || defined(PORTF)
if(port == &PORTC) {
#endif // defined(PORTD/B/F)
hi = PORTC | pinMask;
lo = PORTC & ~pinMask;
next = lo;
if(b & 0x80) next = hi;
// Same as above, just set for PORTC & stripped of comments
asm volatile(
"headC:" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\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 headC" "\n\t"
"rjmp doneC" "\n\t"
"bitTimeC:" "\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"
"doneC:" "\n"
: [byte] "+r" (b), [next] "+r" (next), [count] "+w" (i)
: [port] "I" (_SFR_IO_ADDR(PORTC)), [ptr] "e" (ptr), [hi] "r" (hi),
[lo] "r" (lo));
#if defined(PORTD) || defined(PORTB) || defined(PORTF)
}
#endif // defined(PORTD/B/F)
#if defined(PORTF)
else
#endif
#endif // defined(PORTC)
// PORTF OUTPUT ----------------------------------------------------
#if defined(PORTF)
#if defined(PORTD) || defined(PORTB) || defined(PORTC)
if(port == &PORTF) {
#endif // defined(PORTD/B/C)
hi = PORTF | pinMask;
lo = PORTF & ~pinMask;
next = lo;
if(b & 0x80) next = hi;
// Same as above, just set for PORTF & stripped of comments
asm volatile(
"headF:" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\n\t"
"out %[port], %[hi]" "\n\t"
"rcall bitTimeC" "\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 headF" "\n\t"
"rjmp doneC" "\n\t"
"bitTimeC:" "\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"
"doneC:" "\n"
: [byte] "+r" (b), [next] "+r" (next), [count] "+w" (i)
: [port] "I" (_SFR_IO_ADDR(PORTF)), [ptr] "e" (ptr), [hi] "r" (hi),
[lo] "r" (lo));
#if defined(PORTD) || defined(PORTB) || defined(PORTC)
}
#endif // defined(PORTD/B/C)
#endif // defined(PORTF)
#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)