The X100 expansion board designed for use on the Raspberry Pi (RPi) computer platform. The board supplies RPi with a regulated +5V from a wide-range voltage source and also contains a real-time clock, a RS232 master port, a HDMI to VGA converter, 3-port USB hub, memory card reader, and 8-channel darlington Driver.
Power supply
X100 supplies the RPi with a regulated +5V through the GPIO header using a 5A poly-resettable (PTC) fuse. With the wide voltage input range, the RPi can be powered from a wide variety of external sources such as batteries, 12V power adapters, solar battery sources, etc. Additional +5V power outputs are also available at the pins of the JST servo ports connectors.
Warning: do not connect a +5V supply through the Raspberry Pi micro-USB connector when used with X100. Â
HDMI to VGA
See description on http://elinux.org/RPi_Screens#RGB_analog.2FVGA
Any HDMI to VGA adapter without external PSU might work for a time, but then burn out D1, therefore Do not use HDMI converters powered by the HDMI port! The solution is to either only use externally powered converters.
X100 doesnât use power from RPi HDMI port and has many features that enable it to perform in a superior manner. Among those features you will find:
- Easy to Use: No need of cable and setting
- Conversion: It can convert complete HDMI into VGA video.
- Supports 165MHz/1.65Gbps per channel (6.75Gbps all channel) bandwidth for HDMI Input.
- Supports Analogue Video output up to UXGA and 1080p with 10-bit DAC.
RS232 Master Port
The RS232 port is connected to the UART port on the Raspberry Pi using a MAX3232 interface. The MAX3232 IC converts the 3.3V UART port to RS232 voltages allowing communication with RS232 compatible devices over a DB9 serial cable or with the use of a null-modem cable the board allows terminal access with linux on the Raspberry Pi using a terminal application. The RS232 port can be accessed through the DB9 port.
Real-time clock  (RTCïŒ
Designed to be used in Raspbian and It is a highly accurate real-time clock which connects via the GPIO port on a Raspberry Pi. It uses the GND, SDA and SCL pins.
It utilises the highly accurate NXP PCF2127AT chip and features:
- Very accurate timekeeping (typically±3ppm or <2 minutes deviation per year).
- Integrated crystal that compensates for temperature and age.
- The supplied battery will keep the time for a very long time if the device isnât used and considerably longer if it is.
- 512 bytes of static RAM protected by the backup battery.
- Coin Battery Included!
Set-up (LXTerminal)
Download the latest version operation system of Raspbian âwheezyâ and install.  http://www.raspberrypi.org/downloads
- Make sure weâve got the latest firmware drivers. Sudo apt-get update
- Download the RTC driver wget http://afterthoughtsoftware.com/files/llinux-image-3.6.11-atsw-rtc_1.0_armhf.deb
- Extract the RTC driver tar xzvf rtc-3.6.11.tar.gz
- Install the RTC driver sudo dpkg -i linux-image-3.6.11-atsw-rtc_1.0_armhf.deb
- Copy the RTC moduleâs boot file to the Raspberry Pi boot directory. sudo cp /boot/vmlinuz-3.6.11-atsw-rtc+ /boot/kernel.img
- Open the âmodulesâ file in the nano text editor Sudo nano /etc/modules
- Add the following text, one per line i2c-bcm2708  rtc-pcf2127a
- Press âCTRL + Xâ to exit, Type âYâ to save those changes, Press âEnterâ to return
- Open ârc.localâ for editing Sudo nano /etc/rc.local
- Register the RTC module and set the system clock from the RTC. echo pcf2127a 0x51 > /sys/class/i2c-adapter/i2c-1/new_device ( sleep 2; hwclock -s ) &
- Press âCTRL + Xâ to exit, Type âYâ to save those changes, Press âEnterâ to return.
- Reboot sudo reboot
- Set the system time.sudo date MMDDHHMMYYYY.SS (MM= Month, DD= Date, HH= Hour, MM= Minute, YYYY= Year, SS= Second ) Example 2013 Jan 4 , 11:39:00 , sudo date 010411392013.00
- Copy the system time into the clock module sudo hwclock -w
- To read the time from the clock module sudo hwclock -r
- To copy the time from the clock module to the system sudo hwclock -s
For more detail: X100/105/200/300 Function Expansion Board for Raspberry Pi B/B+