user37469: Can I set pin 13 to output 5v, then put arduino pro mini to sleep and it maintains 5v going through pin 13 while in sleep mode?
I know there are various "levels" of sleep - can a voltage be maintained on a pin for all/any of the sleep modes?

user27653: Given the absence of clarity on the driving state of pins during sleep, consider connecting Pin 13 to an SR Latch or the gate of a MOSFET.
An SR Latch will hold it's output high or low until a high is presented on the Set or Reset inputs, so connect Pin 13 to the Set input, with a pull-down resistor -- even if the MCU in sleep mode allows the voltage output to drain away to 0v, the SR Latch will maintain it's output.
A MOSFET gate has a non-trivial capacitance which can hold a charge if the gate's driver goes high-impedance, thus holding the gate open after the driver is disconnected.

user30005: 
can a voltage be maintained on a pin for all/any of the sleep modes?

yes.

37469: <p>Can I set pin 13 to output 5v, then put arduino pro mini to sleep and it maintains 5v going through pin 13 while in sleep mode?</p>

<p>I know there are various "levels" of sleep - can a voltage be maintained on a pin for all/any of the sleep modes?</p>
 27653: <p>Given the absence of clarity on the driving state of pins during sleep, consider connecting Pin 13 to an <a href="https://www.allaboutcircuits.com/textbook/digital/chpt-10/s-r-latch/" rel="nofollow noreferrer">SR Latch</a> or the gate of a MOSFET.</p>

<p>An SR Latch will hold it's output high or low until a high is presented on the Set or Reset inputs, so connect Pin 13 to the Set input, with a pull-down resistor -- even if the MCU in sleep mode allows the voltage output to drain away to 0v, the SR Latch will maintain it's output.</p>

<p>A MOSFET gate has a non-trivial capacitance which can hold a charge if the gate's driver goes high-impedance, thus holding the gate open after the driver is disconnected.</p>
 30005: <blockquote>
  <p>can a voltage be maintained on a pin for all/any of the sleep modes?</p>
</blockquote>

<p>yes.</p>
