Merge pull request #260 from markusgritsch/dev

Changed the ws2812 byte order from GRB to RGB

README.md

@@ -383,9 +383,9 @@ They'll be available as `u8g.<font_name>` in Lua.
 ####Control a WS2812 based light strip
 ```lua
 	-- set the color of one LED on GPIO2 to red
-	ws2812.write(4, string.char(0, 255, 0)) 
+	ws2812.writergb(4, string.char(255, 0, 0))
 	-- set the color of 10 LEDs on GPIO0 to blue
-	ws2812.write(3, string.char(0, 0, 255):rep(10))
+	ws2812.writergb(3, string.char(0, 0, 255):rep(10))
 	-- first LED green, second LED white
-	ws2812.write(4, string.char(255, 0, 0, 255, 255, 255))
+	ws2812.writergb(4, string.char(0, 255, 0, 255, 255, 255))
 ```

app/include/user_config.h

@@ -69,7 +69,7 @@
 #define LUA_USE_MODULES_BIT
 #define LUA_USE_MODULES_U8G
 #define LUA_USE_MODULES_MQTT
-// #define LUA_USE_MODULES_WS2812	// TODO: put this device specific module to device driver section.
+#define LUA_USE_MODULES_WS2812	// TODO: put this device specific module to device driver section.
 #endif /* LUA_USE_MODULES */
 
 // TODO: put device specific module to device driver section.

app/modules/modules.h

@@ -139,7 +139,6 @@
         ROM_MODULES_PWM     \
         ROM_MODULES_WIFI    \
         ROM_MODULES_MQTT    \
-        ROM_MODULES_U8G    \
         ROM_MODULES_I2C     \
         ROM_MODULES_SPI     \
         ROM_MODULES_TMR     \

app/modules/ws2812.c

@@ -8,47 +8,56 @@
  * 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.
+// -- This WS2812 code must be compiled with -O2 to get the timing right.  Read this:
 // -- 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.
+// -- 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);
+  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);
+  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 G R B values.
-// ws2812.write(4, string.char(0, 255, 0)) uses GPIO2 and sets the first LED red.
+// 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(255, 0, 0, 255, 255, 255)) first LED green, second LED white.
-static int ICACHE_FLASH_ATTR ws2812_write(lua_State* L) {
+// ws2812.write(4, string.char(0, 255, 0, 255, 255, 255)) first LED green, second LED white.
+static int ICACHE_FLASH_ATTR ws2812_writergb(lua_State* L)
+{
   const uint8_t pin = luaL_checkinteger(L, 1);
   size_t length;
-  const char *buffer = luaL_checklstring(L, 2, &length);
+  char *buffer = (char *)luaL_checklstring(L, 2, &length); // Cast away the constness.
 
+  // Initialize the output pin:
   platform_gpio_mode(pin, PLATFORM_GPIO_OUTPUT, PLATFORM_GPIO_FLOAT);
   platform_gpio_write(pin, 0);
-  os_delay_us(10);
 
+  // Ignore incomplete Byte triples at the end of buffer:
+  length -= length % 3;
+
+  // Rearrange R G B values to G R B order needed by WS2812 LEDs:
+  size_t i;
+  for (i = 0; i < length; i += 3) {
+    const char r = buffer[i];
+    const char g = buffer[i + 1];
+    buffer[i] = g;
+    buffer[i + 1] = r;
+  }
+
+  // Do not remove these:
+  os_delay_us(1);
+  os_delay_us(1);
+
+  // Send the buffer:
   os_intr_lock();
   const char * const end = buffer + length;
   while (buffer != end) {
@@ -68,7 +77,7 @@ static int ICACHE_FLASH_ATTR ws2812_write(lua_State* L) {
 #include "lrodefs.h"
 const LUA_REG_TYPE ws2812_map[] =
 {
-  { LSTRKEY( "write" ), LFUNCVAL( ws2812_write )},
+  { LSTRKEY( "writergb" ), LFUNCVAL( ws2812_writergb )},
   { LNILKEY, LNILVAL}
 };
 
@@ -77,6 +86,3 @@ LUALIB_API int luaopen_ws2812(lua_State *L) {
   LREGISTER(L, "ws2812", ws2812_map);
   return 1;
 }
-
-// ----------------------------------------------------------------------------
-