diff --git a/ports/atmel-samd/common-hal/pulseio/PulseIn.c b/ports/atmel-samd/common-hal/pulseio/PulseIn.c
index bf6dfa8d58..0b551858c8 100644
--- a/ports/atmel-samd/common-hal/pulseio/PulseIn.c
+++ b/ports/atmel-samd/common-hal/pulseio/PulseIn.c
@@ -283,8 +283,9 @@ void common_hal_pulseio_pulsein_resume(pulseio_pulsein_obj_t* self,
     if (trigger_duration > 0) {
         gpio_set_pin_pull_mode(self->pin, GPIO_PULL_OFF);
         gpio_set_pin_direction(self->pin, GPIO_DIRECTION_OUT);
-
-        common_hal_mcu_disable_interrupts();
+        if(trigger_duration < 1000 ){  // only disable interrupts for < 1 ms
+            common_hal_mcu_disable_interrupts();
+        }
         gpio_set_pin_level(self->pin, !self->idle_state);
         common_hal_mcu_delay_us((uint32_t)trigger_duration);
         gpio_set_pin_level(self->pin, self->idle_state);
diff --git a/ports/atmel-samd/tick.c b/ports/atmel-samd/tick.c
index 5c66df3cb0..9000be4740 100644
--- a/ports/atmel-samd/tick.c
+++ b/ports/atmel-samd/tick.c
@@ -52,7 +52,7 @@ void SysTick_Handler(void) {
 
 void tick_init() {
     uint32_t ticks_per_ms = common_hal_mcu_processor_get_frequency() / 1000;
-    SysTick_Config(ticks_per_ms);
+    SysTick_Config(ticks_per_ms-1);
     NVIC_EnableIRQ(SysTick_IRQn);
 }