Name: RPi EL-BOARD
Type: Raspberry Pi Board
Version: 1.0.0
Author: Dubravko Penezic
Copyright: Creative Commons BY-NC-SA v 3.0
Implemented function:

• Fix RPi BUS Cable Connection
• 10 GPIO with bidirectional level shifting (5V or 3.3V)
• I2C bus with bidirectional level shifting (5V or 3.3V)
• RS232 bus with bidirectional level shifting (5V or 3.3V)
• 2×10 headers for connecting to GND, 3.3V, 5V, 10 pins, I2C and RS232
• Internal AS1117 3.3V voltage regulator (500mA, and 5.1V protection)
• DS3231 RTC
• DS1307 RTC
• AT24Cxx EEPROM module with Write Protection option
• FT232RL RS232 to USB adapter with straight or cross connection of TXD/RXD between RPi and FT232RL
• 3 tactile switches connected to GPIO with 4pin header (GND and 3line to switches)
• RGB LED (or 3 ordinary LED) with transistor controlled output (available on 4 pin header plus 5V) and LM317 current controller
• 6 Selectable 3 pin header for selecting LCD screen BUS or 3 tactile switch and RGB LED possibilities
• 16 pin female header for LCD screen connection

PCB Top & Bottom image:

Schematic:
Schematic in PDF format