# Problem With WakeUp on External for Heltec ESP32 v2

**URL:** <https://www.thethingsnetwork.org/forum/t/problem-with-wakeup-on-external-for-heltec-esp32-v2/33654>\
**Category:** Hardware\
**Created:** [January 24, 2020, 8:25pm UTC](https://www.thethingsnetwork.org/forum/t/problem-with-wakeup-on-external-for-heltec-esp32-v2/33654 "2020-01-24T20:25:28Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![bluejedi](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/bluejedi/32/44639_2.png) [@bluejedi](https://www.thethingsnetwork.org/forum/u/bluejedi)\
**Post date:** [January 27, 2020, 10:14am UTC](https://www.thethingsnetwork.org/forum/t/problem-with-wakeup-on-external-for-heltec-esp32-v2/33654/5 "2020-01-27T10:14:10Z")

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> [@hcfk](#):
>
> I am writing a simple code on Heltec ESP32 v2 board and want to make it deep sleep till an external signal got from PIR.  
> For this GPIO\_NUM\_27 pin as input.  
> But the problem is although the pir is not connected to the pin 27 it wakes up in 2-2.5 seconds I also changed it to low but no affect.  
> I have tried the same with 33 there is no problem or 19.

GPIO27 is wired to LoRa MOSI  
GPIO19 is wired to LoRa MISO

To prevent issues you should not use these GPIO’s to trigger external wakeup interrupts from a PIR.

* * *

Not relevant for your issue, but note that Heltec Wifi LoRa 32 V2 has I2C related configuration issues.  
See the [following post](https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic-part-3/18436/312) for more information.

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