MoBo I/O

Many [re]purposes and debug efforts could aided by a comprehensive description of the various low level protocols available on the XO motherboard. There are a variety of headless and headed connectors visible on the XO. The following is an attempt to identify them completely.

Identifying Connectors

• Headless
  • CN24 - top left of backup battery
  • CN31 - top right of backup battery
  • CN19 - above RAM & "3.3V" label
  • CN1 - front side of motherboard, right of MIC jack
  • CN34 - below MIC header
• Headed

Back

• • J1 - top left of southbridge
  • CN23 - right of SD slot
    • Keyboard connector - LV PS/2
  • CN22 - bottom left of backup battery
    • 1-wire(microlan) interface for battery
  • CN21 - bottom right of CN22
    • PWR in from battery
  • CN26+CN25 - below left and right bottom USB port, respectively
    • Speaker headers

Front

• • CN28 - right of MIC jack
    • backlight
  • CN15 - right of MIC-jack side USB plug
    • MIC header
  • CON4 - bottom of USB plugs on L side of mobo

The XO motherboard also features several standard high and low level protocols.

• I2C
  • Theoretically used for the DCON - A datasheet should be obtained for the Himax HX8837 chip and the I2C pins/traces should be identified.
  • /dev/i2c-0
• 3.3v TTL Serial
  • Easily accessible using a 3.3v level converter and a proper cable.
  • /dev/ttyS0

Tidbits

• Python, C, or SH code to toggle the VGA GPIO is wanted