adding battery page and update the fp, i2c, m2, uext

docs/helios64/battery.md

@@ -0,0 +1,48 @@
+## M2 Connector (P2)
+
+There is at least two type of batteries which is installed in Helios64 board: 
+- Li-Ion
+- Coin-type Battery (CR 1225)
+
+### Li-Ion Battery
+
+The Li-Ion battery is actually installed in to Helios64 caseing, but the battery is connected to the board in following connector:
+
+![LBattery](/helios64/img/hardware/lbat.jpg)
+
+The actual cell of the this Li-Ion battery is the panasonic NCR18650BD, we use 2 cell in serial configuration.
+So the Li-Ion battery is rated at 2980mAh, 8.4Volt.
+The time estimation to full charge this battery is 8.5 Hours.
+
+#### Pinout of the BATT Header
+
+![LBattery](/helios64/img/hardware/batt-pinout.png)
+
+|Pin |Name
+|----|----------
+|  1 |Thermistor
+|  2 |Battery +
+|  3 |Battery +
+|  4 |GND
+|  5 |Battery -
+|  6 |Battery -
+
+
+### Coin Cell Battery
+
+The Location of coin-type battery is shown by this figure: 
+![CBattery](/helios64/img/hardware/cbat.jpg)
+
+The battery type is CR1225, this device has diameter of 12.5mm and 2.5mm thickness.
+In above figure the positive (+) polarity is heading downward to the CPU heatsink side.
+This battery is used only for keep the RTC (Real Time Clock) running.
+
+
+### Notes related to battery 
+
+**To Be Confirmed**
+We have NOT confirmed the operaiton of the RTC without CR1225 Coin Cell Battery, even in the situation with the Li-Ion connected we have NOT the operation of RTC.
+
+The Li-Ion battery design is not for powering device when the main AC supply is disconnected, but as the device support to perform graceful shutdown or hibernate.
+Therfore if you found this device can actually turned on for a while when you push the power button, in the situation the Li-Ion battery is connected (when the main AC power disconnected), this is totally normal situation.
+

docs/helios64/front-panel.md

@@ -68,3 +68,5 @@ The connection between P3 from the Helios64 board to P1 on the front panel PCB b
 Below graphics show the front panel descriptions:
 
 ![Front Panel Label](/helios64/img/front-panel/front-panel-labeled.jpg)
+
+The USB 3.0 Cable are actually already mounted to the front panel PCB and the Helios64 Caseing, you only need to connect the usb male connector at the location illustrated in above figure.

docs/helios64/i2c.md

@@ -142,7 +142,7 @@ root@helios64:~# i2cdetect -y 8
 70: -- -- -- -- -- -- -- --   
 ```
 
-Here we can see there is a device detected at the address 0x3c. We can conclude is our OLED screen, unless you have connected more than just one I2C device on the **J9** header.  
+Here we can see there is a device detected at the address 0x3c. We can conclude is our OLED screen, unless you have connected more than just one I2C device on the **P1** header.  
 
 
 #### Application example

docs/helios64/m2.md

@@ -23,7 +23,8 @@ The maximum size of supported M.2 device is the 228 size.
 ## Notes related to M.2 Card
 The M.2 devices installed in Helios64 is configured as sharing devices with SATA Port 1.
 Therefore if you install M.2 SATA module, you will not be able to access the SATA Port 1.
+In another case, if you use the M.2 USB module, the SATA Port 1 still accessible from the system.
 
 The USB bus is connected to the EHCI Host 0.
 
-The M.2 socket in the Helios64 board does NOT support the USB modem, because the USB modem require the SIM Card connection and another signal. (The GSM Pin is NOT connected in the Helios64 board) 
+The M.2 socket in the Helios64 board does NOT support the USB modem, because the USB modem require the SIM Card connection and another signal.

docs/helios64/uext.md

@@ -47,13 +47,18 @@ Make sure your device is correctly oriented before connecting!
 
 ### SPI and I2C
 
----linked to SPI and I2C pages, TBU---
+The implementation of SPI and I2C in the UEXT connector is follow similar convention in the Helios64 board. Please reffer to this page:
+
+- [SPI](/helios64/hardware/)
+- [I2C](/helios64/I2C/)
+
+---**TBU**---
 
 ### Exception
 
-We have connected the UART bus from the RK3399K to the serial console in the USB-C, so there is no dedicated line of UART in the UEXT connector.
+We have connected the UART bus from the RK3399 to the serial console in the USB-C, so there is no dedicated line of UART in the UEXT connector.
 The UART bus in this UEXT header is the parallel ones with the serial console.
-Therefore if you connect some module which might ***require dedicated serial UART line*** to the RK3399K, this module ***will not be detected***.
+Therefore if you connect some module which might ***require dedicated serial UART line*** to the RK3399, this module ***will not function as expected***.
 
 !!! Notes
        Please note also, that GPS modules in UEXT format also will not work due to similar reason.

mkdocs.yml

@@ -76,15 +76,16 @@ nav:
     - Install directly to eMMC  : 'helios64/install-3.md'
   - Hardware:
     - Overview : 'helios64/hardware.md'
+    - Battery : 'helios64/battery.md'
+    - Front Panel : 'helios64/front-panel.md'
     - GPIO : 'helios64/gpio.md'
     - I2C : 'helios64/i2c.md'
     - LED : 'helios64/led.md'
-    - USB : 'helios64/usb.md'
-    - SPI : 'helios64/spi.md'
-    - UEXT : 'helios64/uext.md'
-    - Front Panel : 'helios64/front-panel.md'
     - M.2 : 'helios64/m2.md'
     - PWM Fan : 'helios64/fan.md'
+    - SPI : 'helios64/spi.md'
+    - UEXT : 'helios64/uext.md'
+    - USB : 'helios64/usb.md'
 - Helios4:
   - Introduction: 'helios4/intro.md'
   - Kit Assembly: 'helios4/kit.md'