# Big ESP32 + SX127x topic part 2

**URL:** <https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic-part-2/11973>\
**Category:** End Devices (Nodes)\
**Created:** [January 23, 2018, 2:11pm UTC](https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic-part-2/11973 "2018-01-23T14:11:55Z")\
**Posts on this page:** 1\
**Showing post:** 97

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**Author:** ![arjanvanb](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/arjanvanb/32/46626_2.png) [@arjanvanb](https://www.thethingsnetwork.org/forum/u/arjanvanb)\
**Post date:** [February 4, 2018, 10:59am UTC](https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic-part-2/11973/97 "2018-02-04T10:59:49Z")

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> [@kalon33](#):
>
> don’t know how to keep OTAA session open when deep sleeping

After an OTAA Join has finished, your node has the very same details you’d have for an ABP device. So: store the DevAddr, the secret session keys NwkSKey and AppSKey, the frequency settings, and keep track of both frame counters. See [OTAA then ABP - #5 by arjanvanb](https://www.thethingsnetwork.org/forum/t/otaa-then-abp/12377/5).

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