diff --git a/sw/airborne/test/nova_test_imu.c b/sw/airborne/test/nova_test_imu.c
index 73fcdbee94..c1bfe019ce 100644
--- a/sw/airborne/test/nova_test_imu.c
+++ b/sw/airborne/test/nova_test_imu.c
@@ -17,7 +17,7 @@ static inline void main_event( void );
 int main( void ) {
   main_init();
   while(1) {
-    if (sys_time_periodic())
+    if (sys_time_check_and_ack_timer(0))
       main_periodic();
     main_event();
   }
@@ -27,7 +27,7 @@ int main( void ) {
 static inline void main_init( void ) {
   mcu_init();
 
-  sys_time_init();
+  sys_time_register_timer((1./PERIODIC_FREQUENCY), NULL);
 
   led_init();
 
diff --git a/sw/airborne/test/peripherals/test_ami601.c b/sw/airborne/test/peripherals/test_ami601.c
index a7adb151ba..05b1a20c5c 100644
--- a/sw/airborne/test/peripherals/test_ami601.c
+++ b/sw/airborne/test/peripherals/test_ami601.c
@@ -46,7 +46,7 @@ static inline void on_mag(void);
 int main( void ) {
   main_init();
   while(1) {
-    if (sys_time_periodic())
+    if (sys_time_check_and_ack_timer(0))
       main_periodic_task();
     main_event_task();
   }
@@ -55,7 +55,7 @@ int main( void ) {
 
 static inline void main_init( void ) {
   mcu_init();
-  sys_time_init();
+  sys_time_register_timer((1./PERIODIC_FREQUENCY), NULL);
 
   LED_ON(4);
   ami601_init();
diff --git a/sw/airborne/test/subsystems/test_ahrs.c b/sw/airborne/test/subsystems/test_ahrs.c
index f05fae0083..797ef517ee 100644
--- a/sw/airborne/test/subsystems/test_ahrs.c
+++ b/sw/airborne/test/subsystems/test_ahrs.c
@@ -49,7 +49,7 @@ static inline void on_mag_event(void);
 int main( void ) {
   main_init();
   while(1) {
-    if (sys_time_periodic())
+    if (sys_time_check_and_ack_timer(0))
       main_periodic_task();
     main_event_task();
   }
@@ -59,7 +59,7 @@ int main( void ) {
 static inline void main_init( void ) {
 
   mcu_init();
-  sys_time_init();
+  sys_time_register_timer((1./PERIODIC_FREQUENCY), NULL);
   imu_init();
   ahrs_aligner_init();
   ahrs_init();
diff --git a/sw/airborne/test/subsystems/test_radio_control.c b/sw/airborne/test/subsystems/test_radio_control.c
index aa35d03667..837f2d59d3 100644
--- a/sw/airborne/test/subsystems/test_radio_control.c
+++ b/sw/airborne/test/subsystems/test_radio_control.c
@@ -41,7 +41,7 @@ static        void main_on_radio_control_frame( void );
 int main( void ) {
   main_init();
   while(1) {
-    if (sys_time_periodic())
+    if (sys_time_check_and_ack_timer(0))
       main_periodic_task();
     main_event_task();
   }
@@ -50,7 +50,7 @@ int main( void ) {
 
 static inline void main_init( void ) {
   mcu_init();
-  sys_time_init();
+  sys_time_register_timer((1./PERIODIC_FREQUENCY), NULL);
   radio_control_init();
   mcu_int_enable();
 }
diff --git a/sw/airborne/test/subsystems/test_settings.c b/sw/airborne/test/subsystems/test_settings.c
index 46fa33f770..e4c1a89316 100644
--- a/sw/airborne/test/subsystems/test_settings.c
+++ b/sw/airborne/test/subsystems/test_settings.c
@@ -49,7 +49,7 @@ float setting_d;
 int main( void ) {
   main_init();
   while(1) {
-    if (sys_time_periodic())
+    if (sys_time_check_and_ack_timer(0))
       main_periodic();
     main_event();
   }
@@ -60,7 +60,7 @@ int main( void ) {
 static inline void main_init( void ) {
 
   mcu_init();
-  sys_time_init();
+  sys_time_register_timer((1./PERIODIC_FREQUENCY), NULL);
   settings_init();
   //  DEBUG_SERVO2_INIT();
   //  LED_ON(1);
diff --git a/sw/airborne/test/test_actuators.c b/sw/airborne/test/test_actuators.c
index 1017865f81..c7380336d0 100644
--- a/sw/airborne/test/test_actuators.c
+++ b/sw/airborne/test/test_actuators.c
@@ -38,7 +38,7 @@ int main(void) {
   main_init();
 
   while(1) {
-    if (sys_time_periodic())
+    if (sys_time_check_and_ack_timer(0))
       main_periodic_task();
     main_event_task();
   }
@@ -48,7 +48,7 @@ int main(void) {
 
 static inline void main_init( void ) {
   mcu_init();
-  sys_time_init();
+  sys_time_register_timer((1./PERIODIC_FREQUENCY), NULL);
   actuators_init();
 }
 
diff --git a/sw/airborne/test/test_adcs.c b/sw/airborne/test/test_adcs.c
index e715655592..01b1781149 100644
--- a/sw/airborne/test/test_adcs.c
+++ b/sw/airborne/test/test_adcs.c
@@ -20,7 +20,7 @@ static struct adc_buf buf_adc[NB_ADC];
 
 int main (int argc, char** argv) {
   mcu_init();
-  sys_time_init();
+  sys_time_register_timer((1./PERIODIC_FREQUENCY), NULL);
   led_init();
   adc_init();
 
@@ -51,7 +51,7 @@ int main (int argc, char** argv) {
   mcu_int_enable();
 
   while(1) {
-    if (sys_time_periodic()) {
+    if (sys_time_check_and_ack_timer(0)) {
       LED_TOGGLE(1);
       uint16_t values[NB_ADC];
       uint8_t i;
diff --git a/sw/airborne/test/test_esc_asctecv1_simple.c b/sw/airborne/test/test_esc_asctecv1_simple.c
index dc2777c182..30afc9ff18 100644
--- a/sw/airborne/test/test_esc_asctecv1_simple.c
+++ b/sw/airborne/test/test_esc_asctecv1_simple.c
@@ -38,7 +38,7 @@ int main(void) {
   main_init();
 
   while(1) {
-    if (sys_time_periodic())
+    if (sys_time_check_and_ack_timer(0))
       main_periodic_task();
     main_event_task();
   }
@@ -48,7 +48,7 @@ int main(void) {
 
 static inline void main_init( void ) {
   mcu_init();
-  sys_time_init();
+  sys_time_register_timer((1./PERIODIC_FREQUENCY), NULL);
 }
 
 
diff --git a/sw/airborne/test/test_esc_mkk_simple.c b/sw/airborne/test/test_esc_mkk_simple.c
index f3eb0de760..3c4e45cdb2 100644
--- a/sw/airborne/test/test_esc_mkk_simple.c
+++ b/sw/airborne/test/test_esc_mkk_simple.c
@@ -38,7 +38,7 @@ int main(void) {
   main_init();
 
   while(1) {
-    if (sys_time_periodic())
+    if (sys_time_check_and_ack_timer(0))
       main_periodic_task();
     main_event_task();
   }
@@ -48,7 +48,7 @@ int main(void) {
 
 static inline void main_init( void ) {
   mcu_init();
-  sys_time_init();
+  sys_time_register_timer((1./PERIODIC_FREQUENCY), NULL);
 }
 
 
diff --git a/sw/airborne/test/test_telemetry.c b/sw/airborne/test/test_telemetry.c
index fbc1dcc302..3752a9bfc1 100644
--- a/sw/airborne/test/test_telemetry.c
+++ b/sw/airborne/test/test_telemetry.c
@@ -27,6 +27,8 @@
 #include "interrupt_hw.h"
 #include "mcu_periph/sys_time.h"
 #include "subsystems/datalink/downlink.h"
+#include "led.h"
+
 static inline void main_init( void );
 static inline void main_periodic( void );
 
@@ -35,7 +37,7 @@ int main(void) {
   main_init();
 
   while (1) {
-    if (sys_time_periodic())
+    if (sys_time_check_and_ack_timer(0))
       main_periodic();
   }
   return 0;
@@ -43,7 +45,7 @@ int main(void) {
 
 static inline void main_init( void ) {
   mcu_init();
-  sys_time_init();
+  sys_time_register_timer((1./PERIODIC_FREQUENCY), NULL);
   mcu_int_enable();
 }