diff --git a/keyboard/hhkb_rn42/MEMO.txt b/keyboard/hhkb_rn42/MEMO.txt
index 36d4afb9..100b4442 100644
--- a/keyboard/hhkb_rn42/MEMO.txt
+++ b/keyboard/hhkb_rn42/MEMO.txt
@@ -2,6 +2,7 @@ Roving RN-42
 ============
 07/16   After fix of voltage dividor on GPIO6, had a trouble that it could not send a char to BT module, though could receive.
         Found R8 had wrong 1K resistor and changed to 10K, after that it can send to the module again. Not sure how it had sent with the wrong 1K before.
+07/18   On Linux, had an USB related trouble; keyobard or console didn't work for some reason. Changing PID cured this problem. Very annoying, took very long time before resolved it.
 
 
 
@@ -28,6 +29,28 @@ DONE:
 - Power selector doesn't work; Q4 MOSFET leaks from Lipo to USB power line. -- use Schottky instead 07/04
 
 
+Lipo
+----
+Sparkfun Polymer Lithium Ion Battery 850mAh:
+https://www.sparkfun.com/products/341
+Lipo Cell spec:
+https://www.sparkfun.com/datasheets/Batteries/063048%20Li-polymer.pdf
+Protection spec:
+http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Prototyping/BatteryProtection.pdf
+                            min     typical max
+over-charge                 4.255   4.280   4.305
+over-charge discover?       4.030   4.080   4.130        
+over-discharge              2.827   2.900   2.973
+over-discharge discover     3.022   3.100   3.178
+
+ADC voltage monitor:    voltage divider 10K+10K(0.5)
+    ADC=V*0.5/2.56*1024
+    V       ADC
+    ------------------
+    4.20    0x347(839)
+    3.10    0x26b(619)
+    
+
 
 
 Configuration
diff --git a/keyboard/hhkb_rn42/Makefile b/keyboard/hhkb_rn42/Makefile
index 7a27a43c..b46b7778 100644
--- a/keyboard/hhkb_rn42/Makefile
+++ b/keyboard/hhkb_rn42/Makefile
@@ -51,12 +51,7 @@ TARGET_DIR = .
 # List C source files here. (C dependencies are automatically generated.)
 SRC +=	keymap_common.c \
 	matrix.c \
-	led.c \
-	serial_uart.c \
-	suart.S \
-	rn42.c \
-	rn42_task.c \
-	main.c
+	led.c
 
 ifdef KEYMAP
     SRC := keymap_$(KEYMAP).c $(SRC)
@@ -135,6 +130,7 @@ COMMAND_ENABLE = yes    	# Commands for debug and configuration
 VPATH += $(TARGET_DIR)
 VPATH += $(TOP_DIR)
 
+include rn42.mk
 include $(TOP_DIR)/protocol.mk
 include $(TOP_DIR)/protocol/lufa.mk
 include $(TOP_DIR)/common.mk
diff --git a/keyboard/hhkb_rn42/rn42.mk b/keyboard/hhkb_rn42/rn42.mk
new file mode 100644
index 00000000..653a8092
--- /dev/null
+++ b/keyboard/hhkb_rn42/rn42.mk
@@ -0,0 +1,11 @@
+RN42_DIR = rn42
+
+SRC +=  serial_uart.c \
+	rn42/suart.S \
+	rn42/rn42.c \
+	rn42/rn42_task.c \
+	rn42/main.c
+
+OPT_DEFS += -DPROTOCOL_RN42
+
+VPATH += $(RN42_DIR)
diff --git a/keyboard/hhkb_rn42/main.c b/keyboard/hhkb_rn42/rn42/main.c
similarity index 99%
rename from keyboard/hhkb_rn42/main.c
rename to keyboard/hhkb_rn42/rn42/main.c
index c84f6b0a..a3a37c07 100644
--- a/keyboard/hhkb_rn42/main.c
+++ b/keyboard/hhkb_rn42/rn42/main.c
@@ -13,6 +13,7 @@
 #include "action_util.h"
 #include "wait.h"
 #include "suart.h"
+#include "suspend.h"
 
 static int8_t sendchar_func(uint8_t c)
 {
diff --git a/keyboard/hhkb_rn42/rn42.c b/keyboard/hhkb_rn42/rn42/rn42.c
similarity index 100%
rename from keyboard/hhkb_rn42/rn42.c
rename to keyboard/hhkb_rn42/rn42/rn42.c
diff --git a/keyboard/hhkb_rn42/rn42.h b/keyboard/hhkb_rn42/rn42/rn42.h
similarity index 100%
rename from keyboard/hhkb_rn42/rn42.h
rename to keyboard/hhkb_rn42/rn42/rn42.h
diff --git a/keyboard/hhkb_rn42/rn42_task.c b/keyboard/hhkb_rn42/rn42/rn42_task.c
similarity index 100%
rename from keyboard/hhkb_rn42/rn42_task.c
rename to keyboard/hhkb_rn42/rn42/rn42_task.c
diff --git a/keyboard/hhkb_rn42/rn42_task.h b/keyboard/hhkb_rn42/rn42/rn42_task.h
similarity index 80%
rename from keyboard/hhkb_rn42/rn42_task.h
rename to keyboard/hhkb_rn42/rn42/rn42_task.h
index d75b0301..8f6c3ab6 100644
--- a/keyboard/hhkb_rn42/rn42_task.h
+++ b/keyboard/hhkb_rn42/rn42/rn42_task.h
@@ -4,6 +4,7 @@
 #include <stdbool.h>
 #include "rn42.h"
 
+void rn42_task_init(void);
 void rn42_task(void);
 
 #endif
diff --git a/keyboard/hhkb_rn42/suart.S b/keyboard/hhkb_rn42/rn42/suart.S
similarity index 100%
rename from keyboard/hhkb_rn42/suart.S
rename to keyboard/hhkb_rn42/rn42/suart.S
diff --git a/keyboard/hhkb_rn42/suart.h b/keyboard/hhkb_rn42/rn42/suart.h
similarity index 100%
rename from keyboard/hhkb_rn42/suart.h
rename to keyboard/hhkb_rn42/rn42/suart.h
diff --git a/rules.mk b/rules.mk
index 7a40d1de..83c9da5f 100644
--- a/rules.mk
+++ b/rules.mk
@@ -565,6 +565,7 @@ $(OBJDIR)/%.o : %.cpp
 # Assemble: create object files from assembler source files.
 $(OBJDIR)/%.o : %.S
 	@echo
+	mkdir -p $(@D)
 	@echo $(MSG_ASSEMBLING) $<
 	$(CC) -c $(ALL_ASFLAGS) $< -o $@