diff --git a/ion/include/ion.h b/ion/include/ion.h
index a104d147f..af1b2af75 100644
--- a/ion/include/ion.h
+++ b/ion/include/ion.h
@@ -26,9 +26,6 @@ void ion_main(int argc, char * argv[]);
 
 namespace Ion {
 
-void msleep(long ms);
-void usleep(long us);
-
 const char * serialNumber();
 const char * softwareVersion();
 const char * patchLevel();
diff --git a/ion/include/ion/timing.h b/ion/include/ion/timing.h
index f5161e1d8..60d32d782 100644
--- a/ion/include/ion/timing.h
+++ b/ion/include/ion/timing.h
@@ -11,6 +11,9 @@ namespace Ion {
 EXTERNC uint32_t millis();
 EXTERNC uint32_t micros();
 
+EXTERNC void msleep(long ms);
+EXTERNC void usleep(long us);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/ion/src/blackbox/Makefile b/ion/src/blackbox/Makefile
index d387bff79..e65cecac8 100644
--- a/ion/src/blackbox/Makefile
+++ b/ion/src/blackbox/Makefile
@@ -12,6 +12,7 @@ objs += $(addprefix ion/src/shared/, \
   events.o \
   power.o \
   random.o \
+  timing.o \
   dummy/backlight.o \
   dummy/battery.o \
   dummy/events_modifier.o \
diff --git a/ion/src/blackbox/ion.cpp b/ion/src/blackbox/ion.cpp
index 1044c8903..d946ac29b 100644
--- a/ion/src/blackbox/ion.cpp
+++ b/ion/src/blackbox/ion.cpp
@@ -3,17 +3,3 @@
 
 void Ion::msleep(long ms) {
 }
-
-#include <chrono>
-
-static auto start = std::chrono::high_resolution_clock::now();
-
-uint32_t Ion::millis() {
-  auto elapsed = std::chrono::high_resolution_clock::now() - start;
-  return std::chrono::duration_cast<std::chrono::milliseconds>(elapsed).count();
-}
-
-uint32_t Ion::micros() {
-  auto elapsed = std::chrono::high_resolution_clock::now() - start;
-  return std::chrono::duration_cast<std::chrono::microseconds>(elapsed).count();
-}
diff --git a/ion/src/emscripten/Makefile b/ion/src/emscripten/Makefile
index 042e45dd6..67085a188 100644
--- a/ion/src/emscripten/Makefile
+++ b/ion/src/emscripten/Makefile
@@ -10,6 +10,7 @@ objs += $(addprefix ion/src/shared/, \
   events_modifier.o \
   power.o \
   random.o \
+  timing.o \
   dummy/backlight.o \
   dummy/battery.o \
   dummy/fcc_id.o \
diff --git a/ion/src/emscripten/main.cpp b/ion/src/emscripten/main.cpp
index ed0d9568c..c753d78af 100644
--- a/ion/src/emscripten/main.cpp
+++ b/ion/src/emscripten/main.cpp
@@ -2,9 +2,6 @@
 #include "display.h"
 #include "events_keyboard.h"
 #include "../../../apps/global_preferences.h"
-extern "C" {
-#include <SDL/SDL.h>
-}
 
 extern "C" {
 const char * IonSoftwareVersion();
@@ -24,7 +21,3 @@ int main(int argc, char * argv[]) {
 
 void Ion::msleep(long ms) {
 }
-
-uint32_t Ion::millis() {
-  return SDL_GetTicks();
-}
diff --git a/ion/src/shared/timing.cpp b/ion/src/shared/timing.cpp
new file mode 100644
index 000000000..ac3180fd4
--- /dev/null
+++ b/ion/src/shared/timing.cpp
@@ -0,0 +1,14 @@
+#include <ion.h>
+#include <chrono>
+
+static auto start = std::chrono::high_resolution_clock::now();
+
+uint32_t Ion::millis() {
+  auto elapsed = std::chrono::high_resolution_clock::now() - start;
+  return std::chrono::duration_cast<std::chrono::milliseconds>(elapsed).count();
+}
+
+uint32_t Ion::micros() {
+  auto elapsed = std::chrono::high_resolution_clock::now() - start;
+  return std::chrono::duration_cast<std::chrono::microseconds>(elapsed).count();
+}
diff --git a/ion/src/simulator/Makefile b/ion/src/simulator/Makefile
index 5df0e25eb..f9965da9f 100644
--- a/ion/src/simulator/Makefile
+++ b/ion/src/simulator/Makefile
@@ -13,6 +13,7 @@ objs += $(addprefix ion/src/shared/, \
   events_modifier.o \
   power.o \
   random.o \
+  timing.o \
   dummy/backlight.o \
   dummy/battery.o \
   dummy/fcc_id.o \
diff --git a/ion/src/simulator/init.cpp b/ion/src/simulator/init.cpp
index df09af645..d20630b14 100644
--- a/ion/src/simulator/init.cpp
+++ b/ion/src/simulator/init.cpp
@@ -116,19 +116,3 @@ void Ion::msleep(long ms) {
     }
   }
 }
-
-static auto start = std::chrono::high_resolution_clock::now();
-
-uint32_t Ion::millis() {
-  sDisplay->redraw();
-  Fl::wait(0);
-  auto elapsed = std::chrono::high_resolution_clock::now() - start;
-  return std::chrono::duration_cast<std::chrono::milliseconds>(elapsed).count();
-}
-
-uint32_t Ion::micros() {
-  sDisplay->redraw();
-  Fl::wait(0);
-  auto elapsed = std::chrono::high_resolution_clock::now() - start;
-  return std::chrono::duration_cast<std::chrono::microseconds>(elapsed).count();
-}
diff --git a/python/port/helpers.cpp b/python/port/helpers.cpp
index 5da28c6a5..a1a22b0be 100644
--- a/python/port/helpers.cpp
+++ b/python/port/helpers.cpp
@@ -4,13 +4,15 @@ extern "C" {
 #include "mphalport.h"
 }
 
-bool micropython_port_should_interrupt() {
+bool micropython_port_should_interrupt(bool force) {
   static int c = 0;
-  c++;
-  if (c%20000 != 0) {
-    return false;
+  if(!force) {
+    c++;
+    if (c%20000 != 0) {
+      return false;
+    }
+    c = 0;
   }
-  c = 0;
   Ion::Keyboard::State scan = Ion::Keyboard::scan();
   if (scan.keyDown((Ion::Keyboard::Key)mp_interrupt_char)) {
     mp_keyboard_interrupt();
diff --git a/python/port/helpers.h b/python/port/helpers.h
index 76abbde0d..acb4f7297 100644
--- a/python/port/helpers.h
+++ b/python/port/helpers.h
@@ -8,7 +8,7 @@ extern "C" {
 
 /* should_interrupt effectively does something once every 20000 calls. It checks
  * if a key is down to raise an interruption flag. */
-bool micropython_port_should_interrupt();
+bool micropython_port_should_interrupt(bool);
 
 #ifdef __cplusplus
 }
diff --git a/python/port/mpconfigport.h b/python/port/mpconfigport.h
index ff7fff87d..25ba668f8 100644
--- a/python/port/mpconfigport.h
+++ b/python/port/mpconfigport.h
@@ -90,7 +90,7 @@
 // (This scheme won't work if we want to mix Thumb and normal ARM code.)
 #define MICROPY_MAKE_POINTER_CALLABLE(p) (p)
 
-#define MICROPY_VM_HOOK_LOOP micropython_port_should_interrupt();
+#define MICROPY_VM_HOOK_LOOP micropython_port_should_interrupt(false);
 
 typedef intptr_t mp_int_t; // must be pointer size
 typedef uintptr_t mp_uint_t; // must be pointer size
diff --git a/python/src/extmod/modutime.c b/python/src/extmod/modutime.c
index f5ffdaa41..829ba0cd5 100644
--- a/python/src/extmod/modutime.c
+++ b/python/src/extmod/modutime.c
@@ -34,13 +34,15 @@
 
 void delay_ms(mp_uint_t delay) {
     uint32_t start = millis();
-    while (millis() - start < delay && !micropython_port_should_interrupt()) {
+    while (millis() - start < delay && !micropython_port_should_interrupt(true)) {
+      msleep(1);
     }
 }
 
 void delay_us(mp_uint_t delay) {
     uint32_t start = micros();
-    while (micros() - start < delay && !micropython_port_should_interrupt()) {
+    while (micros() - start < delay && !micropython_port_should_interrupt(false)) {
+      usleep(1);
     }
 }