# Adafruit Feather 32u4 LoRa - long transmission time after deep sleep

**URL:** <https://www.thethingsnetwork.org/forum/t/adafruit-feather-32u4-lora-long-transmission-time-after-deep-sleep/11678>\
**Category:** End Devices (Nodes)\
**Created:** [January 10, 2018, 9:55pm UTC](https://www.thethingsnetwork.org/forum/t/adafruit-feather-32u4-lora-long-transmission-time-after-deep-sleep/11678 "2018-01-10T21:55:15Z")\
**Posts on this page:** 1\
**Showing post:** 7

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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:** [January 10, 2018, 10:11pm UTC](https://www.thethingsnetwork.org/forum/t/adafruit-feather-32u4-lora-long-transmission-time-after-deep-sleep/11678/7 "2018-01-10T22:11:38Z")

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Also:

> <https://github.com/matthijskooijman/arduino-lmic/commit/6e098863f4a59131ab773c6314a51cd7323a519d>
>
> Before, when no packet was received in RX2, there would be a 3-5 second
> delay (f…or EU868) before calling \`processDnData()\` and emitting
> EV\_TXCOMPLETE. This was the \`DNW2\_SAFETY\_ZONE\` to prevent a subsequent
> TX to collide with a downlink packet that was ongoing but not locked on
> to.
> 
> With this change, \`txDelay()\` is used to still delay the subsequent TX,
> without delaying the \`EV\_TXCOMPLETE\` event, which allows battery-powered
> devices that wait for this event before sleeping to get an extra 3-5
> seconds of sleep for each transmitted packet, improving battery life.
> 
> Closes: #16

And:

> [@LMiC's TX\_COMPLETE event takes 20-30 seconds to fire](https://www.thethingsnetwork.org/forum/t/lmics-tx-complete-event-takes-20-30-seconds-to-fire/2639/8):
>
> It uses a worst-case for that, at SF12 in the RX2 window, that is defined by DNW2\_SAFETY\_ZONE (in lmic.c) with a default of 3 seconds.

This implies the library is delaying even more than the duty cycle would enforce.

So, if it does not know time has passed while sleeping, it will keep delaying after sleep, I’m afraid.

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