# Can the Uno wake a sleeping USB host PC?

**URL:** <https://forum.arduino.cc/t/can-the-uno-wake-a-sleeping-usb-host-pc/54902>\
**Category:** General Guidance\
**Created:** [March 9, 2011, 9:13pm UTC](https://forum.arduino.cc/t/can-the-uno-wake-a-sleeping-usb-host-pc/54902 "2011-03-09T21:13:14Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\
**Post date:** [March 9, 2011, 9:13pm UTC](https://forum.arduino.cc/t/can-the-uno-wake-a-sleeping-usb-host-pc/54902/1 "2011-03-09T21:13:14Z")

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In the project I'm working on, an Arduino will be connected to a host PC via USB. The host PC must be allowed to sleep if idle for some time. (By "sleep", I mean S3 power state.)

My Duemilanove can wake the host PC by sending a 20 ms low pulse through an ATmega328 digital output that I've wired to pin 6 on the FT232RL. (Pin 6 is Ring Indicator.)

Is there a similar / simple way for an Uno to wake a sleeping host PC? Or, do I have to customize the Uno's ATmega8U2 serial-to-USB program to handle this?

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**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\
**Post date:** [May 5, 2021, 4:30pm UTC](https://forum.arduino.cc/t/can-the-uno-wake-a-sleeping-usb-host-pc/54902/2 "2021-05-05T16:30:16Z")

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