diff --git a/CMakeLists.txt b/CMakeLists.txt
index d7b375118..3fc6b45da 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -109,7 +109,7 @@ add_custom_target(
 )
 
 # Emulator
-file(GLOB_RECURSE SOURCES_OSW ./src/*.cpp)
+file(GLOB_RECURSE SOURCES_OSW ./src/*.cpp ./src/swig/*.cxx)
 file(GLOB_RECURSE SOURCES_OSW_EMULATOR ./emulator/src/*.cpp)
 add_executable(emulator.run
     ${SOURCES_OSW}
@@ -158,6 +158,8 @@ target_compile_definitions(emulator.run PUBLIC
     # Comment these as you wish...
     OSW_FEATURE_STATS_STEPS
     OSW_FEATURE_WEATHER
+    OSW_FEATURE_LUA
+    EXAMPLE_LUA
     OSW_SERVICE_CONSOLE
     OSW_APPS_EXAMPLES
     GAME_SNAKE=1
@@ -178,7 +180,7 @@ target_compile_options(emulator.run PUBLIC
     -Wno-deprecated-declarations
   >
   $<$<CONFIG:Release>:
-    -O4
+    -O2
   >
 )
 
diff --git a/emulator/include/Serial.h b/emulator/include/Serial.h
index 20c88810c..63db504b9 100644
--- a/emulator/include/Serial.h
+++ b/emulator/include/Serial.h
@@ -46,6 +46,9 @@ class Serial_t {
     void println();
 
     void flush() {}
+
+    void printf(const char *format, ...);
+
   private:
     std::list<char> inputBuffer;
     int bauds = 0;
diff --git a/emulator/src/Serial.cpp b/emulator/src/Serial.cpp
index fae25e22d..fd04d98a3 100644
--- a/emulator/src/Serial.cpp
+++ b/emulator/src/Serial.cpp
@@ -38,6 +38,18 @@ void Serial_t::println() {
         std::cout << std::endl;
 }
 
+// programmer misses printf...
+void Serial_t::printf(const char *format, ...)
+{
+  char buffer[256];  // or smaller or static &c.
+  va_list args;
+  va_start(args, format);
+  vsprintf(buffer, format, args);
+  va_end(args);
+  Serial.print(buffer);
+}
+
+
 int Serial_t::available() {
     char c;
     if(::read(STDIN_FILENO, &c, 1) > 0) {
@@ -53,4 +65,4 @@ int Serial_t::read() {
     char c = this->inputBuffer.front();
     this->inputBuffer.pop_front();
     return c;
-}
\ No newline at end of file
+}
diff --git a/platformio.ini b/platformio.ini
index ecbd86d84..fba792147 100755
--- a/platformio.ini
+++ b/platformio.ini
@@ -39,6 +39,7 @@ extra_scripts =
 	pre:scripts/build/prebuild_cppflags.py
 	pre:scripts/build/prebuild_lua.py ; Needed to generate the .cxx file(s), enabled via "OSW_FEATURE_LUA" build flag
 build_unflags = -std=gnu++11  # The correct flag will be set by the cppflags python script...
+;
 
 [env:LIGHT_EDITION_V3_3_LUA]
 
@@ -48,10 +49,9 @@ build_flags =
 	-D OSW_TARGET_PLATFORM_HEADER='"platform/LIGHT_EDITION_V3_3.h"'
 	-D OSW_FEATURE_STATS_STEPS
 	-D OSW_FEATURE_WIFI
-;	-D OSW_FEATURE_LUA
+	-D OSW_FEATURE_LUA
+	-D MAKE_LIB
 	-Wdouble-promotion
-	-ffunction-sections
-	-fdata-sections
 	-Wno-deprecated-declarations
 	-fpermissive
 
@@ -66,6 +66,7 @@ build_flags =
 	-D OSW_SERVICE_CONSOLE
 	-D OSW_FEATURE_WIFI
 build_type = debug
+lib_ignore = LUA
 
 [env:LIGHT_EDITION_V4_0]
 build_flags =
@@ -75,6 +76,7 @@ build_flags =
 	-D OSW_FEATURE_WIFI
 	-D OSW_FEATURE_WIFI_ONBOOT
 build_type = debug
+lib_ignore = LUA
 
 ; Light edition other stuff
 [env:LIGHT_EDITION_DEV_LUA]
@@ -109,6 +111,7 @@ build_flags =
 	-D OSW_FEATURE_WIFI_APST
 	-D OSW_FEATURE_WIFI_ONBOOT
 build_type = debug
+lib_ignore = LUA
 
 ; GPS edition other stuff
 [env:GPS_EDITION_DEV_ROTATED]
@@ -124,3 +127,4 @@ build_flags =
 	-D OSW_FEATURE_WIFI_APST
 	-D OSW_FEATURE_WIFI_ONBOOT
 build_type = debug
+lib_ignore = LUA
diff --git a/scripts/build/prebuild_lua.py b/scripts/build/prebuild_lua.py
index 036b5fc8d..39852e70c 100644
--- a/scripts/build/prebuild_lua.py
+++ b/scripts/build/prebuild_lua.py
@@ -70,7 +70,7 @@ def getSwigPath():
     # And compile luac for compressing lua chunks
     print("Building luac ...")
     ##    return_code = os.system("cd ./lib/LUA/; gcc -O2 -std=c89 -DLUA_USE_C89 -DMAKE_LUAC -o ../../build/luac onelua.c -lm")
-    return_code = os.system("cd ./lib/LUA/; make luac; cp luac ../../build/luac")
+    return_code = os.system("cd ./lib/LUA/; make luac")
     if return_code != 0:
         print("Building lua compiler (luac) failed with return code:")
         print(return_code)
@@ -79,7 +79,7 @@ def getSwigPath():
         print("Building lua compiler (luac) successful")
 
     print("Compiling lua bytecode with luac ...")
-    os.system("cd src.lua; for i in $(find . -iname '*.lua'); do echo compiling $i; ../build/luac -s -o ../data/lua/$i $i; done")
+    os.system("cd src.lua; for i in $(find . -iname '*.lua'); do echo compiling $i; ./lib/LUA/luac -s -o ../data/lua/$i $i; done")
 
 else:
     print("Skipping building osw_wrap.cxx with swig because OSW_FEATURE_LUA is not defined")
diff --git a/src/apps/watchfaces/OswAppWatchfaceZwilight.cpp b/src/apps/watchfaces/OswAppWatchfaceZwilight.cpp
index b8277529e..829d23a23 100644
--- a/src/apps/watchfaces/OswAppWatchfaceZwilight.cpp
+++ b/src/apps/watchfaces/OswAppWatchfaceZwilight.cpp
@@ -78,7 +78,7 @@ bool OswAppWatchfaceZwilight::getTwilights() {
     lua_pushboolean(luaState, false); // true
 
     if (lua_pcall(luaState, 8, 0, 0)) {
-        printf("xxxxx8\n");
+//        Serial.printf("xxxxx8\n");
         printLuaError();
         cleanupLuaState();
         return false;
@@ -88,7 +88,7 @@ bool OswAppWatchfaceZwilight::getTwilights() {
         lua_getglobal(luaState, "getTimes");
         lua_pushnumber(luaState, i);
         if (lua_pcall(luaState, 1, 1, 0)) {
-            printf("xxxx33333333 knock out\n");
+//            Serial.printf("xxxx33333333 knock out\n");
             printLuaError();
             cleanupLuaState();
             return false;
@@ -103,7 +103,7 @@ bool OswAppWatchfaceZwilight::getTwilights() {
     for (int i = 1; i <=11; ++i) {
         if ( lua_geti(luaState, -1, i) == LUA_TNUMBER) { // Times
             sunTimes[i] = lua_tonumber(luaState, -1);
-            printf("xxxxx SunTime.times[%d]=%f\n", i, sunTimes[i]);
+            Serial.printf("xxxxx SunTime.times[%d]=%f\n", i, sunTimes[i]);
         } else {
             sunTimes[i] = -10000;
         }
@@ -117,7 +117,7 @@ bool OswAppWatchfaceZwilight::getTwilights() {
     }
 
     #else 
-    #error "LUA not defined"
+    #warning "LUA not defined"
     #endif
 
     return true;
@@ -186,7 +186,7 @@ void OswAppWatchfaceZwilight::drawWatch(int32_t year, int32_t month, int32_t day
         day_indicator_angle -= 360;
     while (day_indicator_angle < 0)
         day_indicator_angle += 360;
-    hal->gfx()->drawRing(CENTER_X + 115*cosf_tlu(day_indicator_angle), CENTER_Y - 115*sinf_tlu(day_indicator_angle),
+    hal->gfx()->drawRing(CENTER_X + 114*cosf_tlu(day_indicator_angle), CENTER_Y - 114*sinf_tlu(day_indicator_angle),
                               5, 2, sun_color, true);
 
     // sunTimes
@@ -200,7 +200,7 @@ void OswAppWatchfaceZwilight::drawWatch(int32_t year, int32_t month, int32_t day
             day_indicator_angle += 360;
 
         int16_t x0, y0, x1, y1;
-        int16_t r1 = 120;
+        int16_t r1 = 119;
         int16_t r2 = 105;
         x0 = CENTER_X + r1*cosf_tlu(day_indicator_angle);
         y0 = CENTER_Y - r1*sinf_tlu(day_indicator_angle);
@@ -351,7 +351,6 @@ void OswAppWatchfaceZwilight::onButton(Button id, bool up, OswAppV2::ButtonState
         return; // if the button was handled by the defaults, we are done here
 }
 
-
 void OswAppWatchfaceZwilight::onStop() {
     OswAppV2::onStop();
 
diff --git a/src/osw_lua.cpp b/src/osw_lua.cpp
index af4a5bac9..bc6cedb56 100644
--- a/src/osw_lua.cpp
+++ b/src/osw_lua.cpp
@@ -29,8 +29,10 @@
 
 #include "lprefix.h"
 
-
 #include <stddef.h>
+#ifdef OSW_EMULATOR
+#include <Serial.h>
+#endif
 
 extern "C" {
 #include "lua.h"
@@ -51,7 +53,7 @@ static const luaL_Reg loadedlibs[] = {
     {LUA_COLIBNAME, luaopen_coroutine},
     {LUA_TABLIBNAME, luaopen_table},
     {LUA_IOLIBNAME, luaopen_io},
-//   {LUA_OSLIBNAME, luaopen_os},
+    {LUA_OSLIBNAME, luaopen_os},
     {LUA_STRLIBNAME, luaopen_string},
     {LUA_MATHLIBNAME, luaopen_math},
     {LUA_UTF8LIBNAME, luaopen_utf8},
@@ -63,7 +65,6 @@ static const luaL_Reg loadedlibs[] = {
     {NULL, NULL}
 };
 
-/*
 LUALIB_API void luaL_openlibs (lua_State* L) {
     const luaL_Reg* lib;
     // "require" functions from 'loadedlibs' and set results to global table 
@@ -72,7 +73,6 @@ LUALIB_API void luaL_openlibs (lua_State* L) {
         lua_pop(L, 1);  // remove lib 
     }
 }
-*/
 
 void printLuaStack(lua_State *L) {
     int top = lua_gettop(L);
@@ -85,22 +85,29 @@ void printLuaStack(lua_State *L) {
         {
             // booleans
             case LUA_TBOOLEAN:
+                if (lua_toboolean(L, index))
+                    Serial.println("true");
+                else
+                    Serial.println("false");
                 Serial.printf("%s\n", lua_toboolean(L, index) ? "true" : "false");
                 break;
 
             // numbers
             case LUA_TNUMBER:
-                Serial.printf("%f\n", lua_tonumber(L, index));
+                  Serial.println(lua_tonumber(L, index));
+//                Serial.printf("%f\n", lua_tonumber(L, index));
                 break;
 
         // strings
             case LUA_TSTRING:
-                Serial.printf("%s\n", lua_tostring(L, index));
+                  Serial.println(lua_tostring(L, index));
+//                Serial.printf("%s\n", lua_tostring(L, index));
                 break;
 
             // other
             default:
-                Serial.printf("%s\n", lua_typename(L, type));
+                Serial.println(lua_typename(L, type));
+//                Serial.printf("%s\n", lua_typename(L, type));
                 break;
         }
     }
diff --git a/src/swig/osw.i b/src/swig/osw.i
index df512d740..904240346 100644
--- a/src/swig/osw.i
+++ b/src/swig/osw.i
@@ -58,5 +58,11 @@ void halToLua(lua_State *L) {
 
 %include <std_string.i>
 %include "stdint.i"
-%include "Print.h"
+%{
+#ifdef OSW_EMULATOR
+#include "FakePrint.h"
+#else
+#include "Print.h"
+#endif
+%}
 %include "osw_hal.h"