nodemcu-firmware/app/modules/ws2812.c

90 lines
2.7 KiB
C

#include "lualib.h"
#include "lauxlib.h"
#include "platform.h"
#include "auxmods.h"
#include "lrotable.h"
/**
* All this code is mostly from http://www.esp8266.com/viewtopic.php?f=21&t=1143&sid=a620a377672cfe9f666d672398415fcb
* from user Markus Gritsch.
* I just put this code into its own module and pushed into a forked repo,
* to easily create a pull request. Thanks to Markus Gritsch for the code.
*
*/
// ----------------------------------------------------------------------------
// -- 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.write(pin, "string")
// Byte triples in the string are interpreted as R G B values
// and sent to the hardware as G R B.
// ws2812.write(4, string.char(255, 0, 0)) uses GPIO2 and sets the first LED red.
// ws2812.write(3, string.char(0, 0, 255):rep(10)) uses GPIO0 and sets ten LEDs blue.
// ws2812.write(4, string.char(0, 255, 0, 255, 255, 255)) first LED green, second LED white.
static int ICACHE_FLASH_ATTR ws2812_write(lua_State* L) {
const uint8_t pin = luaL_checkinteger(L, 1);
size_t length;
const char *buffer = luaL_checklstring(L, 2, &length);
//ignore incomplete Byte triples at the end of buffer
length -= length % 3;
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;
size_t i = 1;
while (buffer + i <= end) {
uint8_t mask = 0x80;
while (mask) {
(buffer[i] & mask) ? send_ws_1(pin_num[pin]) : send_ws_0(pin_num[pin]);
mask >>= 1;
}
i += ((i % 3) == 1) ? -1 : 2;
}
os_intr_unlock();
return 0;
}
#define MIN_OPT_LEVEL 2
#include "lrodefs.h"
const LUA_REG_TYPE ws2812_map[] =
{
{ LSTRKEY( "write" ), LFUNCVAL( ws2812_write )},
{ LNILKEY, LNILVAL}
};
LUALIB_API int luaopen_ws2812(lua_State *L) {
// TODO: Make sure that the GPIO system is initialized
LREGISTER(L, "ws2812", ws2812_map);
return 1;
}
// ----------------------------------------------------------------------------