From 7dcdbbadf1a397b132b2b2af8f0212a07b5f4754 Mon Sep 17 00:00:00 2001
From: Erick Ahmed <engineering@erickahmed.com>
Date: Wed, 24 Jun 2026 17:10:37 +0200
Subject: [PATCH] Implement print for UART logging

---
 Core/Inc/main.h    |  2 +-
 Core/Src/cansend.c | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/Core/Inc/main.h b/Core/Inc/main.h
index 4f23e18..950de2d 100644
--- a/Core/Inc/main.h
+++ b/Core/Inc/main.h
@@ -52,7 +52,7 @@ extern "C" {
 #include <stdio.h>
 #define DEBUG_PRINT(...) printf(__VA_ARGS__)
 #else
-#define DEBUG_PRINT(...)
+#define DEBUG_PRINT(...) uart_printf(__VA_ARGS__)
 #endif
 /* USER CODE END EM */
 
diff --git a/Core/Src/cansend.c b/Core/Src/cansend.c
index eb2e567..afb4f00 100644
--- a/Core/Src/cansend.c
+++ b/Core/Src/cansend.c
@@ -20,11 +20,46 @@
 #include "main.h"
 #include "cmsis_os.h"
 #include "canlog.h"
+#include <stdio.h>
+#include <stdarg.h>
+#include "cmsis_os.h"
+#include "stm32f4xx.h"
 /* USER CODE END Includes */
 
 extern UART_HandleTypeDef huart1;
 extern osSemaphoreId_t xUARTDMASemaphore;
 extern osMessageQueueId_t xUARTQueue;
+extern UART_HandleTypeDef huart1;
+extern osSemaphoreId_t xUARTDMASemaphore;
+
+/* BEGIN uart_printf */
+/**
+  * @brief  Implementation of a simple print to UART.
+  * @param  arguments: strings to print
+  * @retval None
+  */
+void uart_printf(const char *fmt, ...)
+{
+  static char buf[128];
+  va_list args;
+  va_start(args, fmt);
+  int len = vsnprintf(buf, sizeof(buf), fmt, args);
+  va_end(args);
+
+  if (len > 0)
+  {
+    if (osKernelGetState() == osKernelRunning && __get_IPSR() == 0)
+    {
+      if (osSemaphoreAcquire(xUARTDMASemaphore, osWaitForever) == osOK)
+      {
+        if (HAL_UART_Transmit_DMA(&huart1, (uint8_t*)buf, len) != HAL_OK) osSemaphoreRelease(xUARTDMASemaphore);
+        else osSemaphoreAcquire(xUARTDMASemaphore, osWaitForever);
+      }
+    }
+    else HAL_UART_Transmit(&huart1, (uint8_t*)buf, len, HAL_MAX_DELAY);
+  }
+}
+/* END uart_printf */
 
 /* BEGIN format_can_message */
 /**