-// modifier bits
-#define MOD_LCTRL (1<<0)
-#define MOD_LSHIFT (1<<1)
-#define MOD_LALT (1<<2)
-#define MOD_LGUI (1<<3)
-#define MOD_RCTRL (1<<4)
-#define MOD_RSHIFT (1<<5)
-#define MOD_RALT (1<<6)
-#define MOD_RGUI (1<<7)
-
-
+#define BIT_LCTRL (1<<0)
+#define BIT_LSHIFT (1<<1)
+#define BIT_LALT (1<<2)
+#define BIT_LGUI (1<<3)
+#define BIT_RCTRL (1<<4)
+#define BIT_RSHIFT (1<<5)
+#define BIT_RALT (1<<6)
+#define BIT_RGUI (1<<7)
+#define BIT_LCTL BIT_LCTRL
+#define BIT_RCTL BIT_RCTRL
+#define BIT_LSFT BIT_LSHIFT
+#define BIT_RSFT BIT_RSHIFT
+
+
+// TODO: change variable name: usb_keyboard_ or usb_kb_