# How to wake on USB connection

**URL:** <https://community.particle.io/t/how-to-wake-on-usb-connection/59393>\
**Category:** Firmware\
**Created:** [February 15, 2021, 6:08am UTC](https://community.particle.io/t/how-to-wake-on-usb-connection/59393 "2021-02-15T06:08:34Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Jeremiah](https://avatars.discourse-cdn.com/v4/letter/j/13edae/32.png) [@Jeremiah](https://community.particle.io/u/Jeremiah)\
**Post date:** [February 15, 2021, 6:08am UTC](https://community.particle.io/t/how-to-wake-on-usb-connection/59393/1 "2021-02-15T06:08:35Z")

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Hi there!  
I am using a Boron that sleeps for a long period in ULTRA\_LOW\_POWER mode (STOP mode would also be OK), then periodically wakes up to take sensor readings.  
The Boron is currently powered via the 5V VUSB pin. 3.3V Li+ powering would also be OK for this application.  
I’m wondering how to set it up so that the device automatically wakes up whenever a USB cable is inserted?  
I have thought of using Li+ to power the Boron and connecting VUSB to the wakeup pin (D8?). However, I’m unsure if this would cause backfeeding to my power supply on Li+.

I’ve read a few offhand posts where people have mentioned this as a possibility. Just wondering if there’s anyone who has actually done it? Or, is there a better approach I should know about?

Thanks in advance! Really enjoying the board so far!

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**Author:** ![ScruffR](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/scruffr/32/6952_2.png) [@ScruffR](https://community.particle.io/u/ScruffR)\
**Post date:** [February 15, 2021, 6:45am UTC](https://community.particle.io/t/how-to-wake-on-usb-connection/59393/2 "2021-02-15T06:45:24Z")

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When connecting VUSB to a GPIO make sure you reduce the 5V down to no more than 3.3V as none of the GPIO pins on Gen3 devices are 5V tolerant.

You also cannot power a Boron via the 3v3 pin and Li+ requires 3.6…4.2V to run safely.

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**Author:** ![Rftop](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/rftop/32/16896_2.png) [@Rftop](https://community.particle.io/u/Rftop)\
**Post date:** [February 15, 2021, 4:55pm UTC](https://community.particle.io/t/how-to-wake-on-usb-connection/59393/3 "2021-02-15T16:55:55Z")

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@Jeremiah, Below are results from my Solar Testing that might be useful to your Application.

_Device OS 2.0.0.rc-1 , Boron LTE …  
Hibernate Sleep will wake the Boron LTE when the Solar Panel Cycles._

That would be similar to [you] inserting a USB cable, but you also have the VUSB pin powered, so I’m not sure. Hibernate might be worth a try.  
Here’s the [post](https://community.particle.io/t/boron-solar-charging-with-1-5-0-rc1/54680/39).

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/particle/original/3X/3/2/3291e3c9351789fe8620ae5bcec8d3fec67ff221.png) [@system](https://community.particle.io/u/system)\
**Post date:** [August 17, 2021, 4:56am UTC](https://community.particle.io/t/how-to-wake-on-usb-connection/59393/4 "2021-08-17T04:56:04Z")

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