.. zephyr:code-sample:: lorawan-class-a
:name: LoRaWAN class A device
:relevant-api: lorawan_api
Join a LoRaWAN network and send a message periodically.
Overview
********
A simple application to demonstrate the :ref:`LoRaWAN subsystem <lorawan_api>` of Zephyr.
Building and Running
********************
This sample can be found under
:zephyr_file:`samples/subsys/lorawan/class_a` in the Zephyr tree.
Before building the sample, make sure to select the correct region in the
``prj.conf`` file.
The following commands build and flash the sample.
.. zephyr-app-commands::
:zephyr-app: samples/subsys/lorawan/class_a
:board: nucleo_wl55jc
:goals: build flash
:compact:
Important Notes for Multiple Runs
*********************************
By default, this example will only succeed the first time it is run. On subsequent join attempts, the LoRaWAN network server may reject the join request due to a hardcoded ``dev_nonce`` value. According to the LoRaWAN specification, ``dev_nonce`` must increment for every new connection attempt.
To run this sample multiple times, choose one of the following options:
1. **Manually Increment ``dev_nonce``:**
Modify the sample code to increment ``join_cfg.otaa.dev_nonce`` before each connection attempt and ensure it is preserved across reboots.
2. **Built-in Zephyr Settings Implementation:**
Enable :kconfig:option:`CONFIG_LORAWAN_NVM_SETTINGS` in the Kconfig. This allows proper storage and reuse of configuration settings, including the ``dev_nonce``, across multiple runs.
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