https://devzone.nordicsemi.com/f/nordic-q-a/92930/nrf52840-mpu-fault-isr-taking-too-longHi, I&#39;ve got a GPIO interrupt callback that collects an ADC reading. All is fine until there. But when interrupts become numerous (~3/5k triggers / sec), a MPU FAULT appears. After some tests, I&#39;m assuming it comes from the adc_read() (fromen-USTelligent Community 13Tue, 18 Oct 2022 14:04:16 GMThttps://devzone.nordicsemi.com/thread/391223?ContentTypeID=1Tue, 18 Oct 2022 14:04:16 GMT137ad170-7792-4731-bb38-c0d22fbe4515:45584308-f442-44a1-9198-66acd5f7a0efAnomalySmith<p>Yes, finally I decided to change the logic even if it brings limitations in the final design.</p> <p>Thanks.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/391222?ContentTypeID=1Tue, 18 Oct 2022 13:53:07 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ca93ac07-e59b-4ebe-b282-77b75b4eca42Einarh<p>Hello</p> <p>I&#39;m not sure if the adc_read() function is blocking, but if it is then you should avoid calling it in an ISR.</p> <p>Instead you could try using adc_read_async(), or alternatively use a semaphore to signal from the ISR and call adc_read in your main thread.</p> <p>Best regards,</p> <p>Einar</p><div style="clear:both;"></div>