Expansion Port GPIO

TracNav(TOC)

The general purpose I/O header allows access to the second UART, various power control pins
and the SPI pins.

Power Enable - When pulled low, the main CMUcam3 regulator is disabled causing the board
to draw less than 0.01uA. All devices are shutoff and lose all active state information. When
the line is released or pulled high, the board will reboot. By default, the pin is internally pulled
high.

AUX Power - This pin can be confi gured to either externally power the board, or power an
expansion board. By default, the pin is connected to the 3.3volt internal supply. By removing
resistor R11 and adding a jumper resistor in place of R6, the pin is connected to the main
power before the 5 volt regulator.

Image(gpio-expansion.png)

POWER ENABLE
  • Pulling this pin low will gate power to the entire camera board. This will disable the processor, camera and FIFO causing the board to consume less than 1uW of power. This pin is pulled high by default with a pullup resistor.
    CAM RESET
    • This pin can be used as external I/O if the camera state is not required. Normally this pin resets the camera module and should not be used.
      TX2
    • The transmit pin on UART2 is not level shifted and hence can not be directly connected to a PC or none TTL external device. This pin can also be used as GPIO.
      RX2
    • The receive pin on UART2 is not level shifted and hence can not be directly connected to a PC or none TTL external device. This pin can also be used as GPIO.
      CS
    • On reboot, if this pin is held low, the LPC2106 will enter bootstrap mode. Reboot can be externally induced by pulsing the power enable pin. Normally this pin will be controlled by the MMC driver. This pin can also be used as GPIO or as the SPI chip select when an MMC card is not inserted.
      MOSI
    • Normally this pin is controlled by the MMC driver. This pin can also be used as GPIO or as an SPI output when an MMC card is not inserted.
      MISO
    • Normally this pin is controlled by the MMC driver. This pin can also be used as GPIO or as an SPI input when an MMC card is not inserted.
      SCK
    • Normally this pin is controlled by the MMC driver. This pin can also be used as GPIO or as the SPI clock pin when an MMC card is not inserted.

gpio-expansion.png - GPIO Expansion Port (57.6 kB) Anthony Rowe, 04/28/2007 12:34 pm