Update doc

keyboard/hhkb_rn42/MEMO.txt

@@ -1,12 +1,37 @@
 Roving RN-42
 ============
 
-TODO
-----
 Bug:
 - with Nexus5 keyboard and mouse are very laggy.
 
+- lose USB connection during power-down mode
+    - USB initialize code in main() causes this - WRONG
+    - Do not power-down during USB connection is active - DONE 11/11
+        (USB_DeviceState == USB_DEVICE_Configured) is used to check USB connection
+        matrix_power_down() matrix.c - 11/23
+
+Todo:
+
+Design:
+- remove MCU dependent power saving code from core/keyboard
+    - it should be located in project matrix.c - DONE 11/23
+- HHKB matrix.c needs matrix_prev?
+    - is_modified() is obsolete now. really needs?
+
+
+LUFA:
+USB connection check: state of USB deivce
+- USB_DeviceState:
+    USB_Deivce_State_t { Unattached, Powered, Default, Addressed, Configured*, Suspended* }
+- USB_IsInitialized: state of LUFA core setup
+    becomes true in USB_Init()  USBController_AVR8.c
+    becomes false in USB_Disable()  USBController_AVR8.c
+- USB_VBUS_GetStatus(): state of VBUS(power/connection)
+- USB_Disable() detaches, disables all interrupts, controller, PLL, regulater.
+
+
 Power saving:
+- confirm suspend mode lufa.c: matrix_power_*, suspend_wakeup_condition
 - 8MHz clock
 - When not connected in a few minutes get into deep sleep to save battery life
 - CTS is needed for waking up from deep sleep? How deep sleep is activated?
@@ -19,6 +44,9 @@ Power saving:
     - high resistor 100K/1M?
         capacitor   10nF
         http://www.eevblog.com/forum/beginners/measuring-battery-voltage-without-consuming-current/
+- During USB suspend change clock source to internal RC from external Xtal(6.8)
+- FRZCLK: you can freeze clock for power saving. still WAKEUPI and VBUSTI interrupts are available while freezing.(21.7.3)
+- Suspend: Clear Suspend Bit, Freeze clock, disable PLL, MCU sleep(21.13)
 
 Improving:
 - BT LED; connecting, linked, sleeping, deep sleeping
@@ -306,6 +334,10 @@ SM,5        Auto Connect ANY Mode (Mode =ANY)
 SM,6        automatically reconnect(Mode =Pair)
                 confirm: auto connect works well but difficult to enter command mode.
 
+SR,Z        removes all remote addresses for reconnecting.
+                can be used to connect another host
+SR,I        registers last inquiry address
+
 
 Fast data mode
 --------------

keyboard/hhkb_rn42/PowerSave.txt

@@ -0,0 +1,102 @@
+RN-42
+=====
+
+HHKB key switch power control
+-----------------------------
+MOS FET Nch: BSS138 or IRLML6344T, either works and no apparent difference.
+Normally on(pull-up) or off(pull-down)? interms of power saving it prefers pull-down?
+
+Pull-down will be better for power saving, normally off.
+
+
+
+Used Timer
+----------
+
+8MHz clock
+----------
+1) 16MHz xtal with system prescaler div2: F_CPU=8MHz, F_USB=16MHz
+2) 8MHz xtal with div1: F_CPU=8MHz, F_USB=8MHz
+Hardware USART doesn't work at 115200bps with 8MHz(F_CPU).
+
+workaround:
+a) use Sotwre serial for communcation with RN-42
+b) reduce baud of RN-42 to lower rate;(factory default is 115200bps)
+10/03
+
+
+
+Slave mode
+----------
+Discovery/Inquire
+Connect/Page
+
+SI,0012
+SJ,0012
+InqWindw=0100
+PagWindw=0100
+
+
+Sniff mode
+----------
+0.625ms * <hex>
+SW,0320     Very sluggish. Type is not lost but very slow to register.
+SW,0160     Still sluggish. may transposed? can type but ...
+            Mouse point move intermittently
+SW,0020     feel a bit late like stumble(20ms)
+SW,0010     feel no latency(10ms)
+
+
+Deep sleep
+----------
+SW,8010
+
+
+TX power
+--------
+SY,fff4
+
+
+IO pins
+-------
+S%,1000         status led and connection control don't work
+                GPIO5: status LED
+                GPIO6: Connection control
+                GPIO2: linked status
+
+
+
+
+
+Ver 6.15 04/26/2013
+(c) Roving Networks
+***Settings***
+BTA=00066667BBE9
+BTName=tmkBT-BBE9
+Baudrt(SW4)=115K
+Mode  =DTR
+Authen=1
+Bonded=0
+Rem=001BDC06415B
+***ADVANCED Settings***
+SrvName= keyboard/mouse
+SrvClass=0000
+DevClass=1F00
+InqWindw=0012
+PagWindw=0012
+CfgTimer=255
+StatuStr=NULL
+HidFlags=3c
+DTRtimer=8
+KeySwapr=0
+***OTHER Settings***
+Profile= HID
+CfgChar= $
+SniffEna=8010
+LowPower=0          S|,
+TX Power=fff4       SY,
+IOPorts= 0
+IOValues=0
+Sleeptmr=0
+DebugMod=0
+RoleSwch=0