# LoRa Mac Node - OTAA

**URL:** <https://www.thethingsnetwork.org/forum/t/lora-mac-node-otaa/19676>\
**Category:** End Devices (Nodes)\
**Created:** [November 12, 2018, 3:04am UTC](https://www.thethingsnetwork.org/forum/t/lora-mac-node-otaa/19676 "2018-11-12T03:04:19Z")\
**Posts on this page:** 1\
**Showing post:** 12

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**Author:** ![nestorayuso](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/nestorayuso/32/35697_2.png) [@nestorayuso](https://www.thethingsnetwork.org/forum/u/nestorayuso)\
**Post date:** [November 19, 2018, 9:01pm UTC](https://www.thethingsnetwork.org/forum/t/lora-mac-node-otaa/19676/12 "2018-11-19T21:01:49Z")

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Hi, your code works with ABP and does not work on OTAA because downlink fails because the your implementation of RTC is not good.

> [@LoRa Mac Node with EFM32PG custom board + SX1276 or RFM95 module](https://www.thethingsnetwork.org/forum/t/lora-mac-node-with-efm32pg-custom-board-sx1276-or-rfm95-module/18770):
>
> Hi All, I could port the code for LoRa Mac Node onto EFM32PG custom board with SX1276/RFM95 changeable module. The LoRa radio module goes on socket, SX1276 is 915Mhz and RFM95 is 868Mhz versions. I am using RFM95 868Mhz with ABP for now and it does transmit and I can see the uplink message under my Laird geateway on TTN, but that happens only one time when the powered up. I have a few questions: In the board.c file, under BoardInitMCU() there is a function call CalibrateSystemWakeupTime( ).H…

let’s see if i can help you. but i am sure [LoRaMac Node (SX1276) with EFM32PG host - ABP works but OTAA not working · Issue #588 · Lora-net/LoRaMac-node · GitHub](https://github.com/Lora-net/LoRaMac-node/issues/588) is not a good place.

can you publish your code on github so i can review it?

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