From c65341c6626cfafb1b91d4245b2824059916c32a Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 14:18:07 +0200
Subject: [PATCH 01/22] Change periodic timers to one shot timers

---
 Core/Src/main.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/Core/Src/main.c b/Core/Src/main.c
index ce25a02..70e1f62 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -151,11 +151,8 @@ int main(void)
   /* USER CODE END RTOS_SEMAPHORES */
 
   /* USER CODE BEGIN RTOS_TIMERS */
-  xHeartbeatTimerCAN1 = osTimerNew(vLEDHeartbeat, osTimerPeriodic, &led_can1, NULL);
-  osTimerStart(xHeartbeatTimerCAN1, 250U);
-
-  xHeartbeatTimerCAN2 = osTimerNew(vLEDHeartbeat, osTimerPeriodic, &led_can2, NULL);
-  osTimerStart(xHeartbeatTimerCAN2, 250U);
+  xHeartbeatTimerCAN1 = osTimerNew(vLEDHeartbeat, osTimerOnce, &led_can1, NULL);
+  xHeartbeatTimerCAN2 = osTimerNew(vLEDHeartbeat, osTimerOnce, &led_can2, NULL);
 
   if (xHeartbeatTimerCAN1 == NULL || xHeartbeatTimerCAN2 == NULL) Error_Handler();
   /* USER CODE END RTOS_TIMERS */

From 7c7d7745225f8bc47ed17ac24f9576fd9f0aae3e Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 14:18:28 +0200
Subject: [PATCH 02/22] Create semaphores for signalling new message in FIFO
 buffer

---
 Core/Src/main.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Core/Src/main.c b/Core/Src/main.c
index 70e1f62..f6cf1ad 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -147,7 +147,13 @@ int main(void)
   /* USER CODE END RTOS_MUTEX */
 
   /* USER CODE BEGIN RTOS_SEMAPHORES */
-  /* add semaphores, ... */
+  osSemaphoreId_t xLEDSemaphoreCAN1;
+  xLEDSemaphoreCAN1 = osSemaphoreNew(255, 0, NULL);
+
+  osSemaphoreId_t xLEDSemaphoreCAN2;
+  xLEDSemaphoreCAN2 = osSemaphoreNew(255, 0, NULL);
+
+  if (xLEDSemaphoreCAN1 == NULL || xLEDSemaphoreCAN2 == NULL) Error_Handler();
   /* USER CODE END RTOS_SEMAPHORES */
 
   /* USER CODE BEGIN RTOS_TIMERS */

From d6ea04e33ed63cfc8b696ddfbe82d409c75fb860 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 14:18:40 +0200
Subject: [PATCH 03/22] Change variable name

---
 Core/Src/canlog.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Core/Src/canlog.c b/Core/Src/canlog.c
index 85a5a6f..21e3395 100644
--- a/Core/Src/canlog.c
+++ b/Core/Src/canlog.c
@@ -109,7 +109,7 @@ void vCANLoggerListen(void *argument)
 
     for (;;)
     {
-        if (osMessageQueueGet(queue, &msg, NULL, osWaitForever) == osOK)
+        if (osMessageQueueGet(queue, &message, NULL, osWaitForever) == osOK)
         {
             // TODO: parse message send message to serial/uart
             // TODO: add rtos semaphore to blink the LED with the timer already set

From 2e2150ebd2ef9ab425d22e168a32ad31776d7b00 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 14:19:30 +0200
Subject: [PATCH 04/22] Write HIGH status on LED on incoming CAN message and
 start 25ms timer

---
 Core/Src/canlog.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Core/Src/canlog.c b/Core/Src/canlog.c
index 21e3395..4090915 100644
--- a/Core/Src/canlog.c
+++ b/Core/Src/canlog.c
@@ -112,7 +112,9 @@ void vCANLoggerListen(void *argument)
         if (osMessageQueueGet(queue, &message, NULL, osWaitForever) == osOK)
         {
             // TODO: parse message send message to serial/uart
-            // TODO: add rtos semaphore to blink the LED with the timer already set
+
+            HAL_GPIO_WritePin(led_can1.port, led_can1.pin, GPIO_PIN_SET);
+            osTimerStart(xHeartbeatTimerCAN1, 25U);
         }
     }
     /* CODE END */

From ebbd1816fa986ee4f1cb101c9dcb4cef0f60ad28 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 14:19:44 +0200
Subject: [PATCH 05/22] Write LOW status on LED when timer triggers

---
 Core/Src/canlog.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Core/Src/canlog.c b/Core/Src/canlog.c
index 4090915..2f1d3ed 100644
--- a/Core/Src/canlog.c
+++ b/Core/Src/canlog.c
@@ -131,7 +131,7 @@ void vLEDHeartbeat(void *argument)
 {
   /* CODE BEGIN */
   LED_Config *led = (LED_Config*)argument;
-  HAL_GPIO_TogglePin(led->port, led->pin);
+  HAL_GPIO_WritePin(led->port, led->pin, GPIO_PIN_RESET);
   /* CODE END */
 }
 /* END vLEDHeartbeat */

From 7ece650f725fb09e4b64ebb01da929ac07490700 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 14:49:54 +0200
Subject: [PATCH 06/22] Move declaration on top

---
 Core/Src/main.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/Core/Src/main.c b/Core/Src/main.c
index f6cf1ad..5a0b414 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -66,8 +66,14 @@ LED_Config led_can1 = {GPIOB, GPIO_PIN_2};
 LED_Config led_can2 = {GPIOB, GPIO_PIN_5};
 LED_Config led_error = {GPIOB, GPIO_PIN_3};
 
+osSemaphoreId_t xLEDSemaphoreCAN1;
+osSemaphoreId_t xLEDSemaphoreCAN2;
+
 osTimerId_t xHeartbeatTimerCAN1;
 osTimerId_t xHeartbeatTimerCAN2;
+
+osMessageQueueId_t xCAN1RxQueue;
+osMessageQueueId_t xCAN2RxQueue;
 /* USER CODE END PV */
 
 /* Private function prototypes -----------------------------------------------*/
@@ -147,10 +153,7 @@ int main(void)
   /* USER CODE END RTOS_MUTEX */
 
   /* USER CODE BEGIN RTOS_SEMAPHORES */
-  osSemaphoreId_t xLEDSemaphoreCAN1;
   xLEDSemaphoreCAN1 = osSemaphoreNew(255, 0, NULL);
-
-  osSemaphoreId_t xLEDSemaphoreCAN2;
   xLEDSemaphoreCAN2 = osSemaphoreNew(255, 0, NULL);
 
   if (xLEDSemaphoreCAN1 == NULL || xLEDSemaphoreCAN2 == NULL) Error_Handler();
@@ -164,10 +167,7 @@ int main(void)
   /* USER CODE END RTOS_TIMERS */
 
   /* USER CODE BEGIN RTOS_QUEUES */
-  osMessageQueueId_t xCAN1RxQueue;
   xCAN1RxQueue = osMessageQueueNew(32, sizeof(CanMessage_t), NULL);
-
-  osMessageQueueId_t xCAN2RxQueue;
   xCAN2RxQueue = osMessageQueueNew(32, sizeof(CanMessage_t), NULL);
 
   if (xCAN1RxQueue == NULL || xCAN2RxQueue == NULL) Error_Handler();

From 1b38c0f29ae8c77fa91f0a2504d04ea7ed7355a7 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 14:50:43 +0200
Subject: [PATCH 07/22] Release semaphore on incoming message

- Discard previous solution with timer only
---
 Core/Src/canlog.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Core/Src/canlog.c b/Core/Src/canlog.c
index 2f1d3ed..8f2b8d3 100644
--- a/Core/Src/canlog.c
+++ b/Core/Src/canlog.c
@@ -113,9 +113,11 @@ void vCANLoggerListen(void *argument)
         {
             // TODO: parse message send message to serial/uart
 
-            HAL_GPIO_WritePin(led_can1.port, led_can1.pin, GPIO_PIN_SET);
-            osTimerStart(xHeartbeatTimerCAN1, 25U);
+
+            bus = (hcan->Instance == CAN1) ? xLEDSemaphoreCAN1 : xLEDSemaphoreCAN2
+            osSemaphoreRelease(bus);
         }
+
     }
     /* CODE END */
 }

From de6dc24dd30641bcd1ca241e3f8310c9500fe373 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 14:51:33 +0200
Subject: [PATCH 08/22] Acquire semaphore and restart timer if new message
 incoming

---
 Core/Src/canlog.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/Core/Src/canlog.c b/Core/Src/canlog.c
index 8f2b8d3..d7962ea 100644
--- a/Core/Src/canlog.c
+++ b/Core/Src/canlog.c
@@ -133,7 +133,17 @@ void vLEDHeartbeat(void *argument)
 {
   /* CODE BEGIN */
   LED_Config *led = (LED_Config*)argument;
-  HAL_GPIO_WritePin(led->port, led->pin, GPIO_PIN_RESET);
+
+  if (osSemaphoreAcquire(xCanActivitySemaphore, 0U) == osOK)
+  {
+      HAL_GPIO_WritePin(led->port, led->pin, GPIO_PIN_SET);
+      osTimerStart(xHeartbeatTimerCAN1, 25U);
+  }
+  else
+  {
+      HAL_GPIO_WritePin(led->port, led->pin, GPIO_PIN_RESET);
+  }
+
   /* CODE END */
 }
 /* END vLEDHeartbeat */

From 5f1695dc0d1bff4e3366997c5f0e4b0d9b943d62 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 14:51:46 +0200
Subject: [PATCH 09/22] Start timer once for automatic rearming with semaphore
 release

---
 Core/Src/main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Core/Src/main.c b/Core/Src/main.c
index 5a0b414..e67881e 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -163,6 +163,9 @@ int main(void)
   xHeartbeatTimerCAN1 = osTimerNew(vLEDHeartbeat, osTimerOnce, &led_can1, NULL);
   xHeartbeatTimerCAN2 = osTimerNew(vLEDHeartbeat, osTimerOnce, &led_can2, NULL);
 
+  osTimerStart(xHeartbeatTimerCAN1, 25U);
+  osTimerStart(xHeartbeatTimerCAN2, 25U);
+
   if (xHeartbeatTimerCAN1 == NULL || xHeartbeatTimerCAN2 == NULL) Error_Handler();
   /* USER CODE END RTOS_TIMERS */
 

From 5b500d72ff3da16e31308107dad3327b2b089dff Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 14:56:32 +0200
Subject: [PATCH 10/22] Avoid having to declare additional variable

---
 Core/Src/canlog.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/Core/Src/canlog.c b/Core/Src/canlog.c
index d7962ea..784e805 100644
--- a/Core/Src/canlog.c
+++ b/Core/Src/canlog.c
@@ -113,9 +113,7 @@ void vCANLoggerListen(void *argument)
         {
             // TODO: parse message send message to serial/uart
 
-
-            bus = (hcan->Instance == CAN1) ? xLEDSemaphoreCAN1 : xLEDSemaphoreCAN2
-            osSemaphoreRelease(bus);
+            osSemaphoreRelease( (hcan->Instance == CAN1) ? xLEDSemaphoreCAN1 : xLEDSemaphoreCAN2 );
         }
 
     }

From a75d42faebbfc8d44ee0c0bb5ce944058c1eee4d Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 15:16:23 +0200
Subject: [PATCH 11/22] Create context structure for timer callback

Strucure is made of
-  LED (port, pin)
- Semaphore
- Timer handle
---
 Core/Src/canlog.c |  1 -
 Core/Src/main.c   | 15 +++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/Core/Src/canlog.c b/Core/Src/canlog.c
index 784e805..5164a5a 100644
--- a/Core/Src/canlog.c
+++ b/Core/Src/canlog.c
@@ -141,7 +141,6 @@ void vLEDHeartbeat(void *argument)
   {
       HAL_GPIO_WritePin(led->port, led->pin, GPIO_PIN_RESET);
   }
-
   /* CODE END */
 }
 /* END vLEDHeartbeat */
diff --git a/Core/Src/main.c b/Core/Src/main.c
index e67881e..13e4cae 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -41,6 +41,12 @@ typedef struct {
     //uint32_t timestamp; //Enable TIM2: 42 MHz / (41+1) = 1 MHz → 1 µs tick; 32bit autoreload freerunning
     // this is for getting timestamps on can messages
 } CanMessage_t;
+
+typedef struct {
+    LED_Config *led;
+    osSemaphoreId_t sem;
+    osTimerId_t timer;
+} LEDContext;
 /* USER CODE END PTD */
 
 /* Private define ------------------------------------------------------------*/
@@ -66,6 +72,9 @@ LED_Config led_can1 = {GPIOB, GPIO_PIN_2};
 LED_Config led_can2 = {GPIOB, GPIO_PIN_5};
 LED_Config led_error = {GPIOB, GPIO_PIN_3};
 
+LEDContext ledCtxCAN1;
+LEDContext ledCtxCAN2;
+
 osSemaphoreId_t xLEDSemaphoreCAN1;
 osSemaphoreId_t xLEDSemaphoreCAN2;
 
@@ -109,7 +118,13 @@ int main(void)
   HAL_Init();
 
   /* USER CODE BEGIN Init */
+  ledCtxCAN1.led = &led_can1;
+  ledCtxCAN1.sem = xLEDSemaphoreCAN1;
+  ledCtxCAN1.timer = xHeartbeatTimerCAN1;
 
+  ledCtxCAN2.led = &led_can2;
+  ledCtxCAN2.sem = xLEDSemaphoreCAN2;
+  ledCtxCAN2.timer = xHeartbeatTimerCAN2;
   /* USER CODE END Init */
 
   /* Configure the system clock */

From 75efc4840d33a9cc2a37c53140f10ad2001ed18d Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 15:17:03 +0200
Subject: [PATCH 12/22] Use new  context structure instead of direct pass

---
 Core/Src/canlog.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/Core/Src/canlog.c b/Core/Src/canlog.c
index 5164a5a..0017e6b 100644
--- a/Core/Src/canlog.c
+++ b/Core/Src/canlog.c
@@ -130,16 +130,16 @@ void vCANLoggerListen(void *argument)
 void vLEDHeartbeat(void *argument)
 {
   /* CODE BEGIN */
-  LED_Config *led = (LED_Config*)argument;
+  LEDContext *ctx = (LEDContext*)argument;
 
-  if (osSemaphoreAcquire(xCanActivitySemaphore, 0U) == osOK)
+  if (osSemaphoreAcquire(ctx->sem, 0U) == osOK)
   {
-      HAL_GPIO_WritePin(led->port, led->pin, GPIO_PIN_SET);
-      osTimerStart(xHeartbeatTimerCAN1, 25U);
+      HAL_GPIO_WritePin(ctx->led->port, ctx->led->pin, GPIO_PIN_SET);
+      osTimerStart(ctx->timer, 25U);
   }
   else
   {
-      HAL_GPIO_WritePin(led->port, led->pin, GPIO_PIN_RESET);
+      HAL_GPIO_WritePin(ctx->led->port, ctx->led->pin, GPIO_PIN_RESET);
   }
   /* CODE END */
 }

From 151bac7a13e1c8b6171743226da09dac9339f80d Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 16:08:21 +0200
Subject: [PATCH 13/22] Fix typo

---
 Core/Inc/canlog.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Core/Inc/canlog.h b/Core/Inc/canlog.h
index db865b1..86ec046 100644
--- a/Core/Inc/canlog.h
+++ b/Core/Inc/canlog.h
@@ -44,7 +44,7 @@ extern const osThreadAttr_t vLED_CAN2_Heartbeat_attributes;
   * @param  hcan1 Pointer to the CAN1 handle
   * @param  hcan2 Pointer to the CAN2 handle
   */
-void vCANLoggerInit(CAN_HandleTypeDef *hcan1, CAN_HandleTypeDef *hcan2);
+void CAN_Logger_Init(CAN_HandleTypeDef *hcan1, CAN_HandleTypeDef *hcan2);
 void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan);
 void vCANLoggerListen(void *argument);
 void vLEDHeartbeat(void *argument);

From 2a3d5d17b3aa9ff92bb78057485ae817826e83ab Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 16:08:37 +0200
Subject: [PATCH 14/22] Remove unnecessary declarations

---
 Core/Inc/canlog.h | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/Core/Inc/canlog.h b/Core/Inc/canlog.h
index 86ec046..3effcc3 100644
--- a/Core/Inc/canlog.h
+++ b/Core/Inc/canlog.h
@@ -24,20 +24,10 @@
 
 #include "main.h"
 
-/* Decladerations for queues */
 extern osMessageQueueId_t xCAN1RxQueue;
 extern osMessageQueueId_t xCAN2RxQueue;
-
-/* Decladerations for thread handles and attributes */
-extern osThreadId_t vCAN1_rx;
-extern osThreadId_t vCAN2_rx;
-extern osThreadId_t vLED_CAN1_Heartbeat;
-extern osThreadId_t vLED_CAN2_Heartbeat;
-
-extern const osThreadAttr_t vCAN1_rx_attributes;
-extern const osThreadAttr_t vCAN2_rx_attributes;
-extern const osThreadAttr_t vLED_CAN1_Heartbeat_attributes;
-extern const osThreadAttr_t vLED_CAN2_Heartbeat_attributes;
+extern osSemaphoreId_t xLEDSemaphoreCAN1;
+extern osSemaphoreId_t xLEDSemaphoreCAN2;
 
 /**
   * @brief  Initializes the CAN logger modules, OS threads, queues, and hardware.

From 72ffb2644e764522d23d241fb1cffd4659532cf1 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 16:09:45 +0200
Subject: [PATCH 15/22] Use more clear variable names

---
 Core/Src/main.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/Core/Src/main.c b/Core/Src/main.c
index 13e4cae..36c4b79 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -44,7 +44,7 @@ typedef struct {
 
 typedef struct {
     LED_Config *led;
-    osSemaphoreId_t sem;
+    osSemaphoreId_t semaphore;
     osTimerId_t timer;
 } LEDContext;
 /* USER CODE END PTD */
@@ -72,8 +72,8 @@ LED_Config led_can1 = {GPIOB, GPIO_PIN_2};
 LED_Config led_can2 = {GPIOB, GPIO_PIN_5};
 LED_Config led_error = {GPIOB, GPIO_PIN_3};
 
-LEDContext ledCtxCAN1;
-LEDContext ledCtxCAN2;
+LEDContext ledContextCAN1;
+LEDContext ledContextCAN2;
 
 osSemaphoreId_t xLEDSemaphoreCAN1;
 osSemaphoreId_t xLEDSemaphoreCAN2;
@@ -175,8 +175,8 @@ int main(void)
   /* USER CODE END RTOS_SEMAPHORES */
 
   /* USER CODE BEGIN RTOS_TIMERS */
-  xHeartbeatTimerCAN1 = osTimerNew(vLEDHeartbeat, osTimerOnce, &led_can1, NULL);
-  xHeartbeatTimerCAN2 = osTimerNew(vLEDHeartbeat, osTimerOnce, &led_can2, NULL);
+  xHeartbeatTimerCAN1 = osTimerNew(vLEDHeartbeat, osTimerOnce, &ledContextCAN1, NULL);
+  xHeartbeatTimerCAN2 = osTimerNew(vLEDHeartbeat, osTimerOnce, &ledContextCAN2, NULL);
 
   osTimerStart(xHeartbeatTimerCAN1, 25U);
   osTimerStart(xHeartbeatTimerCAN2, 25U);

From f0d2990b8d025f9c1dc18ebe3594ef28adfe1c3f Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 16:10:00 +0200
Subject: [PATCH 16/22] Move below timer setup

---
 Core/Src/main.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/Core/Src/main.c b/Core/Src/main.c
index 36c4b79..21dfd1b 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -118,13 +118,7 @@ int main(void)
   HAL_Init();
 
   /* USER CODE BEGIN Init */
-  ledCtxCAN1.led = &led_can1;
-  ledCtxCAN1.sem = xLEDSemaphoreCAN1;
-  ledCtxCAN1.timer = xHeartbeatTimerCAN1;
 
-  ledCtxCAN2.led = &led_can2;
-  ledCtxCAN2.sem = xLEDSemaphoreCAN2;
-  ledCtxCAN2.timer = xHeartbeatTimerCAN2;
   /* USER CODE END Init */
 
   /* Configure the system clock */
@@ -200,6 +194,16 @@ int main(void)
   /* add events, ... */
   /* USER CODE END RTOS_EVENTS */
 
+  /* USER CODE BEGIN 3 */
+  ledContextCAN1.led = &led_can1;
+  ledContextCAN1.semaphore = xLEDSemaphoreCAN1;
+  ledContextCAN1.timer = xHeartbeatTimerCAN1;
+
+  ledContextCAN2.led = &led_can2;
+  ledContextCAN2.semaphore = xLEDSemaphoreCAN2;
+  ledContextCAN2.timer = xHeartbeatTimerCAN2;
+  /* USER CODE END 3 */
+
   /* Start scheduler */
   osKernelStart();
 

From ac16f8150eb7682426bdc9ea2f8a6193648363a6 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 16:10:18 +0200
Subject: [PATCH 17/22] Use a more sensible number of semaphores

---
 Core/Src/main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Core/Src/main.c b/Core/Src/main.c
index 21dfd1b..fbefc62 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -162,8 +162,8 @@ int main(void)
   /* USER CODE END RTOS_MUTEX */
 
   /* USER CODE BEGIN RTOS_SEMAPHORES */
-  xLEDSemaphoreCAN1 = osSemaphoreNew(255, 0, NULL);
-  xLEDSemaphoreCAN2 = osSemaphoreNew(255, 0, NULL);
+  xLEDSemaphoreCAN1 = osSemaphoreNew(10, 0, NULL);
+  xLEDSemaphoreCAN2 = osSemaphoreNew(10, 0, NULL);
 
   if (xLEDSemaphoreCAN1 == NULL || xLEDSemaphoreCAN2 == NULL) Error_Handler();
   /* USER CODE END RTOS_SEMAPHORES */

From 4aafa810097b9114330377c67a44ab0fa7d923d2 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 16:14:20 +0200
Subject: [PATCH 18/22] Change CODE BEGIN N value

---
 Core/Src/main.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Core/Src/main.c b/Core/Src/main.c
index fbefc62..f2e11c7 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -215,9 +215,9 @@ int main(void)
   {
     /* USER CODE END WHILE */
 
-    /* USER CODE BEGIN 3 */
+    /* USER CODE BEGIN 4 */
   }
-  /* USER CODE END 3 */
+  /* USER CODE END 4 */
 }
 
 /**
@@ -467,9 +467,9 @@ static void MX_GPIO_Init(void)
   /* USER CODE END MX_GPIO_Init_2 */
 }
 
-/* USER CODE BEGIN 4 */
+/* USER CODE BEGIN 5 */
 
-/* USER CODE END 4 */
+/* USER CODE END 5 */
 
 /**
   * @brief  Period elapsed callback in non blocking mode

From 8777f742aca8239b377a704762954490cbfdaffd Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 16:15:33 +0200
Subject: [PATCH 19/22] Move typedef to header

---
 Core/Inc/canlog.h | 6 ++++++
 Core/Src/main.c   | 6 ------
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Core/Inc/canlog.h b/Core/Inc/canlog.h
index 3effcc3..f95a9ff 100644
--- a/Core/Inc/canlog.h
+++ b/Core/Inc/canlog.h
@@ -29,6 +29,12 @@ extern osMessageQueueId_t xCAN2RxQueue;
 extern osSemaphoreId_t xLEDSemaphoreCAN1;
 extern osSemaphoreId_t xLEDSemaphoreCAN2;
 
+typedef struct {
+    LED_Config *led;
+    osSemaphoreId_t semaphore;
+    osTimerId_t timer;
+} LEDContext;
+
 /**
   * @brief  Initializes the CAN logger modules, OS threads, queues, and hardware.
   * @param  hcan1 Pointer to the CAN1 handle
diff --git a/Core/Src/main.c b/Core/Src/main.c
index f2e11c7..7b5df2f 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -41,12 +41,6 @@ typedef struct {
     //uint32_t timestamp; //Enable TIM2: 42 MHz / (41+1) = 1 MHz → 1 µs tick; 32bit autoreload freerunning
     // this is for getting timestamps on can messages
 } CanMessage_t;
-
-typedef struct {
-    LED_Config *led;
-    osSemaphoreId_t semaphore;
-    osTimerId_t timer;
-} LEDContext;
 /* USER CODE END PTD */
 
 /* Private define ------------------------------------------------------------*/

From 5ec806ffea3522984b03686350e0648d22c12257 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 16:16:14 +0200
Subject: [PATCH 20/22] Add CMSIS include

---
 Core/Inc/canlog.h | 1 +
 Core/Src/main.c   | 1 -
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/Core/Inc/canlog.h b/Core/Inc/canlog.h
index f95a9ff..0ba9cb4 100644
--- a/Core/Inc/canlog.h
+++ b/Core/Inc/canlog.h
@@ -23,6 +23,7 @@
 #define CANLOG_H
 
 #include "main.h"
+#include "cmsis_os.h"
 
 extern osMessageQueueId_t xCAN1RxQueue;
 extern osMessageQueueId_t xCAN2RxQueue;
diff --git a/Core/Src/main.c b/Core/Src/main.c
index 7b5df2f..e3ea066 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -23,7 +23,6 @@
 /* Private includes ----------------------------------------------------------*/
 /* USER CODE BEGIN Includes */
 #include "canlog.h"
-#include <system_error>
 /* USER CODE END Includes */
 
 /* Private typedef -----------------------------------------------------------*/

From 9d4d807cfb7c79165c7771109142a77a641b892c Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 16:21:55 +0200
Subject: [PATCH 21/22] Fix race condition that could cause a hard fault

---
 Core/Src/main.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Core/Src/main.c b/Core/Src/main.c
index e3ea066..82611d8 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -159,6 +159,11 @@ int main(void)
   xLEDSemaphoreCAN2 = osSemaphoreNew(10, 0, NULL);
 
   if (xLEDSemaphoreCAN1 == NULL || xLEDSemaphoreCAN2 == NULL) Error_Handler();
+
+  ledContextCAN1.led = &led_can1;
+  ledContextCAN1.semaphore = xLEDSemaphoreCAN1;
+  ledContextCAN2.led = &led_can2;
+  ledContextCAN2.semaphore = xLEDSemaphoreCAN2;
   /* USER CODE END RTOS_SEMAPHORES */
 
   /* USER CODE BEGIN RTOS_TIMERS */
@@ -169,6 +174,9 @@ int main(void)
   osTimerStart(xHeartbeatTimerCAN2, 25U);
 
   if (xHeartbeatTimerCAN1 == NULL || xHeartbeatTimerCAN2 == NULL) Error_Handler();
+
+  ledContextCAN1.timer = xHeartbeatTimerCAN1;
+  ledContextCAN2.timer = xHeartbeatTimerCAN2;
   /* USER CODE END RTOS_TIMERS */
 
   /* USER CODE BEGIN RTOS_QUEUES */

From 53772ccb7d784315c2060b598c31031b03958d55 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Sun, 14 Jun 2026 16:45:02 +0200
Subject: [PATCH 22/22] Remove error handling as it would cause crash on full
 queue

---
 Core/Src/canlog.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/Core/Src/canlog.c b/Core/Src/canlog.c
index 0017e6b..509a9b2 100644
--- a/Core/Src/canlog.c
+++ b/Core/Src/canlog.c
@@ -82,12 +82,12 @@ void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
     memcpy(message.payload, data, rxHeader.DLC);
 
     osMessageQueueId_t queue = (hcan->Instance == CAN1) ? xCAN1RxQueue : xCAN2RxQueue;
-    if (osMessageQueuePut(queue, &message, 0U, 0U) != osOK) Error_Handler();
-    // TODO: better handling: flash error_led on osTimeout, call Error_Handler() when other errors
-
-    // Issue #1: set an event flag for led task
-    // osEventFlagsSet(xCanEventFlags, (hcan->Instance == CAN1) ? 0x01 : 0x02);
+    if (osMessageQueuePut(queue, &message, 0U, 0U) != osOK)
+    {
+        // TODO: better handling: flash error_led on osTimeout, call Error_Handler() when other errors
 
+        // send errors like queue full via UART
+    }
     /* CODE END */
 }
 /* END HAL_CAN_RxFifo0MsgPendingCallback */