diff --git a/Makefile b/Makefile
index b31f49ec..23a6c04a 100644
--- a/Makefile
+++ b/Makefile
@@ -105,7 +105,7 @@ OBINS := $(GEN_BINS:%=$(BINODIR)/%)
 
 CCFLAGS += 			\
 	-g			\
-	-Ofast			\
+	-Os			\
 	-Wpointer-arith		\
 	-Wundef			\
 	-Werror			\
diff --git a/app/modules/gpio.c b/app/modules/gpio.c
index 551dca8a..74e72756 100644
--- a/app/modules/gpio.c
+++ b/app/modules/gpio.c
@@ -121,28 +121,14 @@ static int lgpio_mode( lua_State* L )
 // Lua: read( pin )
 static int lgpio_read( lua_State* L )
 {
-  unsigned pin;
-  
-  pin = luaL_checkinteger( L, 1 );
-  MOD_CHECK_ID( gpio, pin );
-
-  unsigned level = platform_gpio_read( pin );
-  lua_pushinteger( L, level );
+  lua_pushinteger( L, platform_gpio_read( luaL_checkinteger( L, 1 ) ) );
   return 1; 
 }
 
 // Lua: write( pin, level )
 static int lgpio_write( lua_State* L )
 {
-  unsigned level;
-  unsigned pin;
-  
-  pin = luaL_checkinteger( L, 1 );
-  MOD_CHECK_ID( gpio, pin );
-  level = luaL_checkinteger( L, 2 );
-  if ( level!=HIGH && level!=LOW )
-    return luaL_error( L, "wrong arg type" );
-  platform_gpio_write(pin, level);
+  platform_gpio_write(luaL_checkinteger( L, 1 ), luaL_checkinteger( L, 2 ) & 0x1);
   return 0;  
 }
 
diff --git a/app/modules/node.c b/app/modules/node.c
index 90dd0d96..dc635e3c 100644
--- a/app/modules/node.c
+++ b/app/modules/node.c
@@ -387,6 +387,22 @@ static int node_compile( lua_State* L )
   return 0;
 }
 
+// Lua: node.setcpufreq(int) -- change CPU frequency to 80 or 160 MHz, returns current frequency
+static int node_set_cpu_freq( lua_State* L )
+{
+  uint32_t new_freq = luaL_checkinteger( L, 1 );
+  if(new_freq == 160){
+    REG_SET_BIT(0x3ff00014, BIT(0));
+    os_update_cpu_frequency(160);
+  }else{
+    REG_CLR_BIT(0x3ff00014, BIT(0));
+    os_update_cpu_frequency(80);
+  }
+  new_freq = ets_get_cpu_frequency();
+  lua_pushinteger(L, new_freq);
+  return 1;
+}
+
 // Module function map
 #define MIN_OPT_LEVEL 2
 #include "lrodefs.h"
@@ -407,8 +423,7 @@ const LUA_REG_TYPE node_map[] =
   { LSTRKEY( "output" ), LFUNCVAL( node_output ) },
   { LSTRKEY( "readvdd33" ), LFUNCVAL( node_readvdd33) },
   { LSTRKEY( "compile" ), LFUNCVAL( node_compile) },
-// Combined to dsleep(us, option)  
-// { LSTRKEY( "dsleepsetoption" ), LFUNCVAL( node_deepsleep_setoption) },
+  { LSTRKEY( "setcpufreq" ), LFUNCVAL( node_set_cpu_freq ) },
 #if LUA_OPTIMIZE_MEMORY > 0
 
 #endif