From 5aea63d91caa902f9213e0abf681b264188f9774 Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Tue, 7 Aug 2018 22:47:06 +0200
Subject: [PATCH] SSR: Debugging over USART

---
 ssr/Inc/util.h  |  3 ++-
 ssr/Src/debug.c | 17 +++++++++++++----
 ssr/Src/main.c  |  4 +++-
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/ssr/Inc/util.h b/ssr/Inc/util.h
index 0beed7c..405098c 100644
--- a/ssr/Inc/util.h
+++ b/ssr/Inc/util.h
@@ -38,7 +38,8 @@ static inline void put_u32_be(byte *p, u32 x)
 
 // debug.c
 
-#define DEBUG_SEMIHOSTING
+#undef DEBUG_SEMIHOSTING
+#define DEBUG_USART USART1
 
 void debug_printf(const char *fmt, ...);
 void debug_puts(const char *s);
diff --git a/ssr/Src/debug.c b/ssr/Src/debug.c
index d8b3d63..7fae1e8 100644
--- a/ssr/Src/debug.c
+++ b/ssr/Src/debug.c
@@ -4,9 +4,10 @@
 #include <stdarg.h>
 #include <string.h>
 
+#ifdef DEBUG_SEMIHOSTING
+
 void semi_put_char(char c)
 {
-#ifdef DEBUG_SEMIHOSTING
   // This is tricky, we need to work around GCC bugs
   volatile char cc = c;
   asm volatile (
@@ -17,12 +18,10 @@ void semi_put_char(char c)
     : [msg] "r" (&cc)
     : "r0", "r1"
   );
-#endif
 }
 
 void semi_write_string(char *c)
 {
-#ifdef DEBUG_SEMIHOSTING
   asm volatile (
     "mov r0, #0x04\n"   /* SYS_WRITE0 */
     "mov r1, %[msg]\n"
@@ -31,11 +30,13 @@ void semi_write_string(char *c)
     : [msg] "r" (c)
     : "r0", "r1"
   );
-#endif
 }
 
+#endif
+
 void debug_putc(int c)
 {
+#ifdef DEBUG_SEMIHOSTING
   static char debug_buf[128];
   static int debug_i;
   debug_buf[debug_i++] = c;
@@ -45,6 +46,14 @@ void debug_putc(int c)
       semi_write_string(debug_buf);
       debug_i = 0;
     }
+#endif
+#ifdef DEBUG_USART
+  if (c == '\n')
+    debug_putc('\r');
+  while (!LL_USART_IsActiveFlag_TXE(DEBUG_USART))
+    ;
+  LL_USART_TransmitData8(DEBUG_USART, c);
+#endif
 }
 
 void debug_puts(const char *s)
diff --git a/ssr/Src/main.c b/ssr/Src/main.c
index 3a3f034..cc6e363 100644
--- a/ssr/Src/main.c
+++ b/ssr/Src/main.c
@@ -174,7 +174,9 @@ int main(void)
 	usb_ep_receive(&usb, 0x01, rx_packet, 64);
       }
 
-    // debug_printf("Counter = %d\n", cnt);
+    static int cnt;
+    debug_printf("Counter = %d\n", cnt);
+    cnt++;
 
     //__WFI();
     LL_mDelay(1000);
-- 
2.39.2