https://devzone.nordicsemi.com/f/nordic-q-a/38631/error-20-identifier-nrfx_timer0_inst_idx-is-undefinedHi I am using nRF5_SDK_15.1.0_a8c0c4d\examples\ble_peripheral\ble_app_uart &amp; merged TWI sensor as well as nRF5_SDK_15.1.0_a8c0c4d\examples\peripheral\saadc. TWI works well after merging but SAADC gives error: Consider, I have checked this posten-USTelligent Community 13Tue, 18 Sep 2018 08:22:06 GMThttps://devzone.nordicsemi.com/thread/149168?ContentTypeID=1Tue, 18 Sep 2018 08:22:06 GMT137ad170-7792-4731-bb38-c0d22fbe4515:20fd4d93-aa27-4785-8b69-d07c5b2ae272J&#248;rgen Holmefjord<p>Hi,</p> <p>Do you have the <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.2.0/group__nrf__drv__timer__config.html?cp=4_0_0_6_9_0_26_0_0">legacy TIMER driver configs</a> in your sdk_config.h file? If you do, you need to completely remove these configs from the file in order for the NRFX_TIMER configs to not be overwritten by apply_old_config.h.</p> <p>Also note that you cannot use TIMER0 in an application that use the softdevice. The <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s140.sds/dita/softdevices/s130/sd_resource_reqs/hw_block_interrupt_vector.html?cp=2_3_2_0_6_0">softdevice use TIMER0 instance</a>, and use of this is blocked for user application. TIMER1-4 is available and can be used.</p> <p>Best regards,<br />Jørgen</p><div style="clear:both;"></div>