https://devzone.nordicsemi.com/f/nordic-q-a/16666/hardfault-error-when-writing-to-characteristic-in-uart-interruptHello everyone, When i get message from uart, i need to update my custom service&#39;s characteristic. I tried the code in the below, sd_ble_gatts_value_set function gives me HardFault error. Am I doing something wrong to add characteristic? how shoulden-USTelligent Community 13Wed, 28 Sep 2016 06:28:36 GMThttps://devzone.nordicsemi.com/thread/63763?ContentTypeID=1Wed, 28 Sep 2016 06:28:36 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f673a5e2-b483-4920-ba69-5c40bcf6c734Hakan<p>Thank you this way is better :)</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/63762?ContentTypeID=1Tue, 27 Sep 2016 07:21:29 GMT137ad170-7792-4731-bb38-c0d22fbe4515:4c318d3a-6876-4b71-b91f-ab38d70606ffVidar Berg<p>Sending an SV instruction from an higher interrupt priority context than the SV call (&#39;2&#39;) itself will lead to a hardfault exception. Setting the interrupt priority to &#39;APP LOW&#39; in the initialization of the UART should fix this problem. Calling the sd_ble_gatts_value_set() function in main context as you described will also work.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/63761?ContentTypeID=1Mon, 26 Sep 2016 15:02:56 GMT137ad170-7792-4731-bb38-c0d22fbe4515:66bfc94b-1400-400c-8682-3e373c13d378Hakan<p>I found the solution but i want to know if there is more proper way.</p> <p>If i receive the right message from uart, i set a variable to 1. Then i am checking for that variable is set on for loop in main function. If set, i am writing to characteristic via sd_ble_gatts_value_set</p><div style="clear:both;"></div>