user30839: I have an SPI 128x64 OLED display. Is it safe to power this display's VCC from a digital I/O pin? I would like to do this so I can connect it flush to my arduino's header, and so I can control the power going to the display for a "low power" sleep mode.
Thanks for any responses.

user4143: Unlikely. An IO pin can only provide 25mA sustained, and 40mA peak. A display is likely to require more than that. However check the datasheet for the display. If by chance it should not need more than 25mA maximum (all pixels white) then yes it may be possible. 

user-1: Adafruit model. monochrome 1.3" 128x64 OLED display (similar to yours, I assume):

Display current draw is completely dependent on your usage: each OLED
  LED draws current when on so the more pixels you have lit, the more
  current is used. They tend to draw ~25mA or so in practice but for
  precise numbers you must measure the current in your usage circuit

To be safe, you can use one pin to control a power switch for the display. 

30839: <p>I have an SPI 128x64 OLED display. Is it safe to power this display's VCC from a digital I/O pin? I would like to do this so I can connect it flush to my arduino's header, and so I can control the power going to the display for a "low power" sleep mode.</p>

<p>Thanks for any responses.</p>
 4143: <p>Unlikely. An IO pin can only provide 25mA sustained, and 40mA peak. A display is likely to require more than that. However check the datasheet for the display. If by chance it should not need more than 25mA maximum (all pixels white) then yes it may be possible. </p>
 -1: <p>Adafruit model. monochrome 1.3" 128x64 OLED display (similar to yours, I assume):</p>

<blockquote>
  <p>Display current draw is completely dependent on your usage: each OLED
  LED draws current when on so the more pixels you have lit, the more
  current is used. They tend to draw ~25mA or so in practice but for
  precise numbers you must measure the current in your usage circuit</p>
</blockquote>

<p>To be safe, you can use one pin to control a power switch for the display. </p>
