NRF SDK5

app_timer2

In SDK 16.0.0, app_timer2 is used by default in the examples, New ram efficient app_timer2 implementation:

app_config.h
#define APP_TIMER_ENABLED 1
#define NRF_SORTLIST_ENABLED 1
Makefile
$(SDK_ROOT)/components/libraries/atomic_fifo/nrf_atfifo.c \
$(SDK_ROOT)/components/libraries/timer/app_timer2.c \
$(SDK_ROOT)/components/libraries/timer/drv_rtc.c \
$(SDK_ROOT)/components/libraries/sortlist/nrf_sortlist.c \
 
 
$(SDK_ROOT)/components/libraries/atomic_fifo \
$(SDK_ROOT)/components/libraries/sortlist \
$(SDK_ROOT)/components/libraries/timer \
 
APP_CFLAGS += -DAPP_TIMER_V2
APP_CFLAGS += -DAPP_TIMER_V2_RTC1_ENABLED