https://devzone.nordicsemi.com/f/nordic-q-a/87100/defined-but-not-used-warningI added some functionality to asset_tracker_v2. I used two pins of Nordic chip for following purpose: 1. Detect BMS, pin as Input 2. Reset BMS, pin as output. The pins overlay is added in nrf9160dk_nrf9160_ns.overlay file. The pins configuration and bindingen-USTelligent Community 13Wed, 20 Apr 2022 11:04:30 GMThttps://devzone.nordicsemi.com/thread/363872?ContentTypeID=1Wed, 20 Apr 2022 11:04:30 GMT137ad170-7792-4731-bb38-c0d22fbe4515:2eb0bf0d-75f5-46bb-9ec6-18dd8ad73ebbSigurd Hellesvik<p>Hi,</p> <p>See <a href="https://en.wikipedia.org/wiki/Include_guard">https://en.wikipedia.org/wiki/Include_guard</a>.</p> <p>I recommend that you do not include global variables in header files. <br />I myself would have used get and set functions instead.</p> <p>This stack overflow article also talk about the subject: <br /><a href="https://stackoverflow.com/questions/8108634/global-variables-in-header-file">https://stackoverflow.com/questions/8108634/global-variables-in-header-file</a></p> <p>Regards,<br />Sigurd Hellesvik</p><div style="clear:both;"></div>