MoBo I/O

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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.

Connectors

Headerless

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

Headed

Back

    • J1 - top left of southbridge (3.3v serial port to talk to CPU)
    • CN21 - bottom right of CN22
      • PWR in from battery
    • CN22 - bottom left of backup battery
      • 1-wire(microlan) interface for battery
    • CN23 - right of SD slot
    • CN26+CN25 - below left and right bottom USB port, respectively
      • Speaker headers

Front

    • CN28 - right of MIC jack
      • backlight FFC slot
    • CN15 - right of MIC-jack side USB plug
      • MIC header
    • CON4 - bottom of USB plugs on L side of mobo
      • Camera FFC slot
    • CN27 - top of motherboard
      • Screen pinout

Protocols

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

Wanted

  • Datasheets for all major chips on the XO
  • Python, C, or SH code to control the VGA GPIO
  • The location + code for any and all other GPIOs
  • Positive identification of all aforementioned headers / solder pads / FFC slots
  • Positive pinouts for all aforementioned headers / solder pads / FFC slots
  • Pinout for non-standard VGA connector