https://devzone.nordicsemi.com/f/nordic-q-a/79560/mqtt-publishDear Sir. Using the mqtt_simple project , I inserted a 1 sec timer. Within the timer I want to use the publish routine like this data_publish(&amp;client,MQTT_QOS_1_AT_LEAST_ONCE,&amp;json_text[0],_PUBLISH_SRC.json_reisha_size); Is it OK ? , or theen-USTelligent Community 13Tue, 14 Sep 2021 07:48:09 GMThttps://devzone.nordicsemi.com/thread/329330?ContentTypeID=1Tue, 14 Sep 2021 07:48:09 GMT137ad170-7792-4731-bb38-c0d22fbe4515:44770689-431c-461e-8c8a-9645f74c94e9&#216;yvind<p>Hello,&nbsp;<br /><br />What timer are you using? The k_timer is interrupt based, and the data_publish is effectively interrupt based due to the <a href="https://infocenter.nordicsemi.com/topic/ps_nrf9160/ipc.html?resultof=%22%69%70%63%22%20">Inter Processor Communication between the modem and the application</a>. This will cause issues as you are effectively getting a&nbsp;nested interrupt, and can cause kernel panics. Please see&nbsp;the <a href="https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.6.1/zephyr/reference/kernel/other/interrupts.html#interrupts">interrupts chapter for more information</a><br /><br />We <a href="https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.6.1/zephyr/reference/kernel/threads/workqueue.html#workqueue-threads">recommend using the workqueue threads instead</a>, as <a href="https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.6.1/zephyr/reference/kernel/other/interrupts.html#offloading-isr-work">according to the Offloading ISR work subchapter</a>.</p> <p>Kind regards,<br />Øyvind</p><div style="clear:both;"></div>