diff --git a/mk/librfn.mk b/mk/librfn.mk
index bc695ff..6768da1 100644
--- a/mk/librfn.mk
+++ b/mk/librfn.mk
@@ -7,7 +7,15 @@ $(info Using $(LIBRFN_DIR) path to librfn library)
 endif
 
 OBJS += \
-	ringbuf.o
+	bitops.o \
+	fibre.o \
+	fibre_default.o \
+	list.o \
+	messageq.o \
+	regdump.o \
+	ringbuf.o \
+	time_libopencm3.o \
+	util.o
 
 vpath %.c $(LIBRFN_DIR)/librfn
 vpath %.c $(LIBRFN_DIR)/librfn/libopencm3
diff --git a/projects/rfdsatt/Makefile b/projects/rfdsatt/Makefile
index 125eb9a..d5ca8a4 100644
--- a/projects/rfdsatt/Makefile
+++ b/projects/rfdsatt/Makefile
@@ -30,7 +30,7 @@ OBJS =	attenuator.o board_rfdsatt_4ch.o
 
 LDSCRIPT = ./stm32f103-openblt.ld
 LIBNAME         = opencm3_stm32f1
-DEFS            += -DSTM32F1
+DEFS            += -DSTM32F1 -DF_CPU=48000000
 FP_FLAGS        ?= -msoft-float
 ARCH_FLAGS      = -mthumb -mcpu=cortex-m3 $(FP_FLAGS) -mfix-cortex-m3-ldrd
 
diff --git a/projects/rfdsatt/rfdsatt.c b/projects/rfdsatt/rfdsatt.c
index 3f343a4..39c4a24 100644
--- a/projects/rfdsatt/rfdsatt.c
+++ b/projects/rfdsatt/rfdsatt.c
@@ -26,6 +26,8 @@
 #include <libopencm3/cm3/scb.h>
 #include <libopencm3/cm3/systick.h>
 
+#include <librfn/time.h>
+
 #include <libcommon/iob.h>
 #include <libcommon/microvty.h>
 
@@ -40,19 +42,12 @@ static uint32_t last_reset_cause;
 extern const struct attenuator_cfg board_att_cfg;
 extern struct attenuator_state *board_att_st[];
 
-volatile uint32_t jiffies;
-
-void sys_tick_handler(void)
-{
-	jiffies++;
-}
-
 /* busy wait specified number of ms */
 void msleep(uint32_t delay)
 {
-	uint32_t wake = jiffies + delay;
+	uint32_t wake = time_now() + delay;
 	do {
-	} while (wake > jiffies);
+	} while (wake > time_now());
 }
 
 /***********************************************************************
@@ -65,10 +60,6 @@ static void clock_setup(void)
 	/* HCLK=48MHz; ADC=6MHz; APB1=24MHz; APB2=48MHz; USB=48MHz */
 
 	/* tick rate of 1ms */
-	systick_set_reload(48000);
-	systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);
-	systick_counter_enable();
-	systick_interrupt_enable();
 
 	/* Enable GPIOC clock. */
 	rcc_periph_clock_enable(RCC_GPIOA);