nodemcu-firmware/app/modules/ws2812.c

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#include "lualib.h"
#include "lauxlib.h"
#include "platform.h"
#include "auxmods.h"
#include "lrotable.h"
// ----------------------------------------------------------------------------
// -- This WS2812 code must be compiled with -O2 to get the timing right.
// -- http://wp.josh.com/2014/05/13/ws2812-neopixels-are-not-so-finicky-once-you-get-to-know-them/
// The ICACHE_FLASH_ATTR is there to trick the compiler and get the very first pulse width correct.
static void ICACHE_FLASH_ATTR send_ws_0(uint8_t gpio)
{
uint8_t i;
i = 4; while (i--) GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, 1 << gpio);
i = 9; while (i--) GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, 1 << gpio);
}
static void ICACHE_FLASH_ATTR send_ws_1(uint8_t gpio)
{
uint8_t i;
i = 8; while (i--) GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, 1 << gpio);
i = 6; while (i--) GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, 1 << gpio);
}
// Lua: ws2812(pin, "string")
// Byte triples in the string are interpreted as G R B values.
// gpio.ws2812(4, string.char(0, 255, 0)) uses GPIO2 and sets the first LED red.
// gpio.ws2812(3, string.char(0, 0, 255):rep(10)) uses GPIO0 and sets ten LEDs blue.
// gpio.ws2812(4, string.char(255, 0, 0, 255, 255, 255)) first LED green, second LED white.
static int ICACHE_FLASH_ATTR lgpio_ws2812(lua_State* L)
{
const uint8_t pin = luaL_checkinteger(L, 1);
size_t length;
const char *buffer = luaL_checklstring(L, 2, &length);
platform_gpio_mode(pin, PLATFORM_GPIO_OUTPUT, PLATFORM_GPIO_FLOAT);
platform_gpio_write(pin, 0);
os_delay_us(10);
os_intr_lock();
const char * const end = buffer + length;
while (buffer != end) {
uint8_t mask = 0x80;
while (mask) {
(*buffer & mask) ? send_ws_1(pin_num[pin]) : send_ws_0(pin_num[pin]);
mask >>= 1;
}
++buffer;
}
os_intr_unlock();
return 0;
}
#define MIN_OPT_LEVEL 2
#include "lrodefs.h"
const LUA_REG_TYPE ws2812_map[] =
{
{ LSTRKEY( "write" ), LFUNCVAL( lgpio_ws2812 ) },
{ LNILKEY, LNILVAL}
};
LUALIB_API int ws2812( lua_State *L )
{
// Make sure that the GPIO system is initialized
LREGISTER( L, "ws2812", ws2812_map );
return 1;
}
// ----------------------------------------------------------------------------