diff --git a/core/CMakeLists.txt b/core/CMakeLists.txt
index 6d938ae0c..6c7f0ffe7 100644
--- a/core/CMakeLists.txt
+++ b/core/CMakeLists.txt
@@ -184,3 +184,4 @@ define(LF_PACKAGE_DIRECTORY)
 define(LF_FILE_SEPARATOR)
 define(WORKERS_NEEDED_FOR_FEDERATE)
 define(LF_ENCLAVES)
+
diff --git a/lingua-franca-ref.txt b/lingua-franca-ref.txt
index edf165c42..8b25206ff 100644
--- a/lingua-franca-ref.txt
+++ b/lingua-franca-ref.txt
@@ -1 +1 @@
-fix-concurrency
\ No newline at end of file
+master
\ No newline at end of file
diff --git a/low_level_platform/api/CMakeLists.txt b/low_level_platform/api/CMakeLists.txt
index 599f87e59..4092f6411 100644
--- a/low_level_platform/api/CMakeLists.txt
+++ b/low_level_platform/api/CMakeLists.txt
@@ -14,6 +14,8 @@ elseif(${CMAKE_SYSTEM_NAME} STREQUAL "Rp2040")
     target_link_libraries(lf-low-level-platform-api INTERFACE pico_stdlib)
     target_link_libraries(lf-low-level-platform-api INTERFACE pico_multicore)
     target_link_libraries(lf-low-level-platform-api INTERFACE pico_sync)
+elseif(${CMAKE_SYSTEM_NAME} STREQUAL "STM32F4")
+    target_compile_definitions(lf-low-level-platform-api INTERFACE PLATFORM_STM32F4)
 elseif(${CMAKE_SYSTEM_NAME} STREQUAL "FlexPRET")
     target_compile_definitions(lf-low-level-platform-api INTERFACE PLATFORM_FLEXPRET)
     target_link_libraries(lf-low-level-platform-api INTERFACE fp-sdk)
diff --git a/low_level_platform/api/low_level_platform.h b/low_level_platform/api/low_level_platform.h
index afffd2a9e..1b05e4073 100644
--- a/low_level_platform/api/low_level_platform.h
+++ b/low_level_platform/api/low_level_platform.h
@@ -52,6 +52,8 @@ int lf_critical_section_exit(environment_t* env);
 #include "platform/lf_patmos_support.h"
 #elif defined(PLATFORM_RP2040)
 #include "platform/lf_rp2040_support.h"
+#elif defined(PLATFORM_STM32F4)
+#include "platform/lf_STM32f4_support.h"
 #elif defined(PLATFORM_FLEXPRET)
 #include "platform/lf_flexpret_support.h"
 #elif defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__)
diff --git a/low_level_platform/api/platform/lf_STM32f4_support.h b/low_level_platform/api/platform/lf_STM32f4_support.h
new file mode 100644
index 000000000..19ff2cfa7
--- /dev/null
+++ b/low_level_platform/api/platform/lf_STM32f4_support.h
@@ -0,0 +1,20 @@
+/* STM32 API support for the C target of Lingua Franca. */
+
+#ifndef LF_STM32F4_SUPPORT_H
+#define LF_STM32F4_SUPPORT_H
+
+#define NO_TTY
+
+#include <stm32f4xx_hal.h>
+
+#define PRINTF_TAG "(" PRINTF_TIME ", " PRINTF_MICROSTEP ")"
+#define PRINTF_TIME "%lld"
+#define PRINTF_MICROSTEP "%d"
+
+#define _LF_TIMEOUT 1
+
+#ifdef LF_THREADED
+#error "Threaded runtime not supported on STM32"
+#endif // LF_THREADED
+
+#endif
\ No newline at end of file
diff --git a/low_level_platform/impl/CMakeLists.txt b/low_level_platform/impl/CMakeLists.txt
index ac035dcf4..32cd760c2 100644
--- a/low_level_platform/impl/CMakeLists.txt
+++ b/low_level_platform/impl/CMakeLists.txt
@@ -39,6 +39,11 @@ elseif(${CMAKE_SYSTEM_NAME} STREQUAL "Rp2040")
         ${CMAKE_CURRENT_LIST_DIR}/src/lf_rp2040_support.c
         ${CMAKE_CURRENT_LIST_DIR}/src/lf_atomic_irq.c
     )
+elseif(${CMAKE_SYSTEM_NAME} STREQUAL "STM32F4")
+    set(LF_LOW_LEVEL_PLATFORM_FILES
+        ${CMAKE_CURRENT_LIST_DIR}/src/lf_STM32f4_support.c
+        ${CMAKE_CURRENT_LIST_DIR}/src/lf_atomic_irq.c
+    )
 elseif(${CMAKE_SYSTEM_NAME} STREQUAL "FlexPRET")
     set(LF_LOW_LEVEL_PLATFORM_FILES
         ${CMAKE_CURRENT_LIST_DIR}/src/lf_flexpret_support.c
@@ -50,7 +55,7 @@ elseif(${CMAKE_SYSTEM_NAME} STREQUAL "Patmos")
         ${CMAKE_CURRENT_LIST_DIR}/src/lf_atomic_irq.c
     )
 else()
-    message(FATAL_ERROR "Your platform is not supported! The C target supports FlexPRET, Patmos, Linux, MacOS, nRF52, RP2040, Windows, and Zephyr.")
+    message(FATAL_ERROR "Your platform is not supported! The C target supports FlexPRET, Patmos, Linux, MacOS, nRF52, RP2040, STM32F4, Windows, and Zephyr.")
 endif()
 
 list(APPEND LF_LOW_LEVEL_PLATFORM_FILES ${CMAKE_CURRENT_LIST_DIR}/src/lf_platform_util.c)
diff --git a/low_level_platform/impl/src/lf_STM32f4_support.c b/low_level_platform/impl/src/lf_STM32f4_support.c
new file mode 100644
index 000000000..2cc8ba5a2
--- /dev/null
+++ b/low_level_platform/impl/src/lf_STM32f4_support.c
@@ -0,0 +1,224 @@
+#if defined(PLATFORM_STM32F4)
+
+#include "platform/lf_STM32f4_support.h"
+#include "low_level_platform.h"
+#include "tag.h"
+
+static volatile bool _lf_sleep_interrupted = false;
+static volatile bool _lf_async_event = false;
+
+// nested critical section counter
+static uint32_t _lf_num_nested_crit_sec = 0;
+
+// Timer upper half (for overflow)
+static uint32_t _lf_time_us_high = 0;
+
+#define LF_MIN_SLEEP_NS 10
+
+// Combine 2 32bit works to a 64 bit word (Takes from nrf52 support)
+#define COMBINE_HI_LO(hi, lo) ((((uint64_t)hi) << 32) | ((uint64_t)lo))
+
+void lf_SystemClock_Config();
+void Error_Handler();
+
+TIM_HandleTypeDef htim5;
+
+void _lf_initialize_clock(void) {
+  // Standard initializations from generated code
+  HAL_Init();
+  lf_SystemClock_Config();
+
+  // Configure TIM5 as our 32-bit clock timer
+  __HAL_RCC_TIM5_CLK_ENABLE(); // initialize counter
+  TIM5->CR1 = TIM_CR1_CEN;     // enable counter
+
+  // set prescaler to (16 - 1) = 15
+  // CPU runs a 16MHz so timer ticks at 1MHz
+  //      Which means period of 1 microsecond
+  TIM5->PSC = 15;
+
+  // Setup ISR to increment upper bits
+  TIM5->DIER |= TIM_DIER_CC1IE;
+  NVIC_EnableIRQ(TIM5_IRQn);
+
+  /* This is to make the Prescaler actually work
+   *  For some reason, the Prescaler only kicks in once the timer has reset once.
+   *  Thus, the current solution is to manually ret the value to a really large
+   *  and force it to reset once. Its really jank but its the only way I could
+   *  find to make it work
+   */
+  TIM5->CNT = 0xFFFFFFFE;
+}
+
+// ISR for handling timer overflow -> We increment the upper timer
+void TIM5_IRQHandler(void) {
+  if (TIM5->SR & TIM_FLAG_CC1) {
+    TIM5->SR &= ~TIM_FLAG_CC1;
+    _lf_time_us_high += 1;
+  }
+}
+
+/**
+ * Write the time since boot into time variable
+ */
+int _lf_clock_gettime(instant_t* t) {
+  // Timer is cooked
+  if (!t) {
+    return 1;
+  }
+
+  // Get the current microseconds from TIM5
+  uint32_t now_us_hi_pre = _lf_time_us_high;
+  uint32_t now_us_low = TIM5->CNT;
+  uint32_t now_us_hi_post = _lf_time_us_high;
+
+  // Check if we read the time during a wrap
+  if (now_us_hi_pre != now_us_hi_post) {
+    // There was a wrap. read again and return
+    now_us_low = TIM5->CNT;
+  }
+
+  // Combine upper and lower timers
+  uint64_t now_us = COMBINE_HI_LO((now_us_hi_post - 1), now_us_low);
+  *t = ((instant_t)now_us) * 1000;
+  return 0;
+}
+
+/**
+ * Make the STM32 sleep for set nanoseconds
+ * Based on the lf_nrf52 support implementation
+ */
+int lf_sleep(interval_t sleep_duration) {
+  instant_t target_time;
+  instant_t current_time;
+
+  _lf_clock_gettime(&current_time);
+  target_time = current_time + sleep_duration;
+  // HAL_Delay only supports miliseconds. We try to use that for as long as possible
+  //      before switching to another meothd for finer tuned delay times
+  long delaytime_ms = sleep_duration / 1000000;
+  HAL_Delay(delaytime_ms);
+
+  while (current_time <= target_time)
+    _lf_clock_gettime(&current_time);
+
+  return 0;
+}
+
+/*  sleep until wakeup time but wake up if there is an async event
+ */
+int _lf_interruptable_sleep_until_locked(environment_t* env, instant_t wakeup_time) {
+  // Get the current time and sleep time
+  instant_t now;
+  _lf_clock_gettime(&now);
+  interval_t duration = wakeup_time - now;
+
+  // Edge case handling for super small duration
+  if (duration <= 0) {
+    return 0;
+  } else if (duration < LF_MIN_SLEEP_NS) {
+    instant_t current_time;
+    _lf_clock_gettime(&current_time);
+
+    // We repurpose the lf_sleep function here, just to better streamline the code
+    interval_t sleep_duration = wakeup_time - current_time;
+    lf_sleep(sleep_duration);
+    return 0;
+  }
+
+  // Enable interrupts and prepare to wait
+  _lf_async_event = false;
+  lf_enable_interrupts_nested();
+
+  do {
+    _lf_clock_gettime(&now);
+    // Exit when the timer is up or there is an exception
+  } while (!_lf_async_event && (now < wakeup_time));
+
+  // Disable interrupts again on exit
+  lf_disable_interrupts_nested();
+
+  if (!_lf_async_event) {
+    return 0;
+  } else {
+    return 1;
+  }
+}
+
+// disables the IRQ with support for nested disabling
+int lf_disable_interrupts_nested() {
+  // Disable interrupts if they are currently enabled
+  if (_lf_num_nested_crit_sec == 0) {
+    __disable_irq();
+  }
+
+  // update the depth of disabling interrupts
+  _lf_num_nested_crit_sec++;
+  return 0;
+}
+
+// enables the IRQ (checks if other processes still want it disabled first)
+int lf_enable_interrupts_nested() {
+  // Left the critical section more often than it was entered.
+
+  if (_lf_num_nested_crit_sec <= 0) {
+    return 1;
+  }
+
+  // update the depth of disabling interrupts
+  _lf_num_nested_crit_sec--;
+
+  // We enable interrupts again
+  if (_lf_num_nested_crit_sec == 0) {
+    __enable_irq();
+  }
+  return 0;
+}
+
+int _lf_single_threaded_notify_of_event() {
+  _lf_async_event = true;
+  return 0;
+}
+
+// The following functions are copied from the STM32F4 HAL library
+void lf_SystemClock_Config(void) {
+  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
+  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
+
+  /** Configure the main internal regulator output voltage
+   */
+  __HAL_RCC_PWR_CLK_ENABLE();
+  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE3);
+
+  /** Initializes the RCC Oscillators according to the specified parameters
+   * in the RCC_OscInitTypeDef structure.
+   */
+  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
+  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
+  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
+  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
+  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
+    Error_Handler();
+  }
+
+  /** Initializes the CPU, AHB and APB buses clocks
+   */
+  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
+  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
+  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
+  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
+  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
+
+  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK) {
+    Error_Handler();
+  }
+}
+
+// Called upon error like a hardfault.
+void Error_Handler(void) {
+  __disable_irq();
+  while (1) {
+  }
+}
+
+#endif
\ No newline at end of file
diff --git a/low_level_platform/impl/src/lf_atomic_irq.c b/low_level_platform/impl/src/lf_atomic_irq.c
index 7d78ab445..9bcf6bb0f 100644
--- a/low_level_platform/impl/src/lf_atomic_irq.c
+++ b/low_level_platform/impl/src/lf_atomic_irq.c
@@ -1,5 +1,5 @@
 #if defined(PLATFORM_ARDUINO) || defined(PLATFORM_NRF52) || defined(PLATFORM_ZEPHYR) || defined(PLATFORM_RP2040) ||    \
-    defined(PLATFORM_FLEXPRET) || defined(PLATFORM_PATMOS)
+    defined(PLATFORM_FLEXPRET) || defined(PLATFORM_PATMOS) || defined(PLATFORM_STM32F4)
 /**
  * @author Erling Rennemo Jellum
  * @copyright (c) 2023