From 84c7a6bb6749e43916d76986cd2a43ce6525010a Mon Sep 17 00:00:00 2001
From: gnssuser <gnssuser@github.com>
Date: Thu, 22 May 2025 10:28:00 +0200
Subject: [PATCH] Sample usage USART2 and USART6

printf to USART2
---
 Core/Src/main.c | 34 +++++++++++++++++++++++++++-------
 1 file changed, 27 insertions(+), 7 deletions(-)

diff --git a/Core/Src/main.c b/Core/Src/main.c
index bc27da1..fc24ed7 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -17,11 +17,13 @@
   */
 /* USER CODE END Header */
 /* Includes ------------------------------------------------------------------*/
+#include <usart2_it.h>
+#include <usart6_it.h>
 #include "main.h"
 
 /* Private includes ----------------------------------------------------------*/
 /* USER CODE BEGIN Includes */
-
+#include "printf.h"
 /* USER CODE END Includes */
 
 /* Private typedef -----------------------------------------------------------*/
@@ -59,6 +61,13 @@ static void MX_USART6_UART_Init(void);
 /* Private user code ---------------------------------------------------------*/
 /* USER CODE BEGIN 0 */
 
+/***************************************************************************//**
+* @brief Character send interface for printf function
+*//****************************************************************************/
+void uart_putc (void* p, char c) {
+   Usart2_PutByte(c);
+}
+
 /* USER CODE END 0 */
 
 /**
@@ -94,16 +103,27 @@ int main(void)
   MX_USART6_UART_Init();
   /* USER CODE BEGIN 2 */
 
+   Usart2_Init();
+   Usart6_Init();
+   init_printf(NULL, &uart_putc);   // connect printf to UART
+   printf("Hello world. This is a Nucleo UART and printf sample with IRQ and ring buffer.\n");
   /* USER CODE END 2 */
 
   /* Infinite loop */
   /* USER CODE BEGIN WHILE */
-  while (1)
-  {
-    /* USER CODE END WHILE */
-
-    /* USER CODE BEGIN 3 */
-  }
+   while (1) {
+      static uint32_t Ctr = 0;
+
+      int ch = Usart2_GetByte();
+      if (ch != -1) {                           // new incoming data
+         Usart6_PutByte(ch);                    // UART2rx --> UART6tx
+         printf("%u: %u (0x%02X)\n", Ctr, ch);    // print received character code
+         Ctr++;
+      }
+      /* USER CODE END WHILE */
+
+      /* USER CODE BEGIN 3 */
+   }
   /* USER CODE END 3 */
 }