diff --git a/core/src/usart.c b/core/src/usart.c
index 2a6bcb3..baac6f7 100644
--- a/core/src/usart.c
+++ b/core/src/usart.c
@@ -79,16 +79,21 @@ int		usart_write		(uint8_t _usart,int ch){
 };
 
 int usart_tx		(uint8_t usart,char *b,int size){
-	int n,r;
+	int n,r, tries;
+	tries = 10;
 	for (n=0;n<size;n++){
-		for (r=0;r<10;r++){
-			if (usart_write( usart, *(b++)) >= 0){
-				return ESUCCESS;
+		for (r=0;r<tries;r++){
+			if (usart_write( usart, *b) >= 0){
+				b++;
+				break;
 			};
+			if(r == tries - 1) {
+				return -EFAIL;
+			}
 			wait_ms(1);
 		};
 	};
-	return -EFAIL;
+	return ESUCCESS;
 };