Added support for WS2812 LEDs as a new module

app/include/user_config.h

@@ -65,6 +65,7 @@
 #define LUA_USE_MODULES_OW
 #define LUA_USE_MODULES_BIT
 #define LUA_USE_MODULES_MQTT
+#define LUA_USE_MODULES_WS2812
 #endif /* LUA_USE_MODULES */
 
 // #define LUA_NUMBER_INTEGRAL

app/modules/modules.h

@@ -117,6 +117,15 @@
 #define ROM_MODULES_BIT
 #endif
 
+#if defined(LUA_USE_MODULES_WS2812)
+#define MODULES_WS2812 "ws2812"
+#define ROM_MODULES_WS2812 \
+		_ROM(MODULES_WS2812, luaopen_ws2812, ws2812_map)
+#else
+#define ROM_MODULES_WS2812
+#endif
+
+
 #define LUA_MODULES_ROM      \
         ROM_MODULES_GPIO    \
         ROM_MODULES_PWM		\
@@ -131,7 +140,8 @@
         ROM_MODULES_ADC     \
         ROM_MODULES_UART    \
         ROM_MODULES_OW      \
-        ROM_MODULES_BIT
+        ROM_MODULES_BIT		\
+		ROM_MODULES_WS2812
 
 #endif
 

app/modules/ws2812.c

@@ -0,0 +1,74 @@
+#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;
+}
+
+// ----------------------------------------------------------------------------
+
+
+