From eb58fce25a42c0695eef72bada29c9ace66dad41 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Hru=C5=A1ka?= <ondra@ondrovo.com>
Date: Sat, 23 Dec 2017 16:31:52 +0100
Subject: [PATCH] updated tf

---
 TinyFrame/TF_Integration.c |  7 +++++++
 TinyFrame/TinyFrame.c      | 18 +++++++++++-------
 TinyFrame/TinyFrame.h      |  8 ++++----
 3 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/TinyFrame/TF_Integration.c b/TinyFrame/TF_Integration.c
index de2cf0a..5ddae3d 100644
--- a/TinyFrame/TF_Integration.c
+++ b/TinyFrame/TF_Integration.c
@@ -23,6 +23,13 @@ void TF_WriteImpl(TinyFrame *tf, const uint8_t *buff, size_t len)
         assert_param(osOK == osSemaphoreWait(semVcomTxReadyHandle, 5000));
         uint16_t chunksize = (uint16_t) MIN(total, CHUNK);
         assert_param(USBD_OK == CDC_Transmit_FS((uint8_t *) buff, chunksize));
+
+        PUTS("Tx: ");
+        for(int i=0;i<chunksize; i++) {
+            PRINTF("%02X ", buff[i]);
+        }
+        PUTS("\r\n");
+
         buff += chunksize;
         total -= chunksize;
     }
diff --git a/TinyFrame/TinyFrame.c b/TinyFrame/TinyFrame.c
index 07d4cf8..fb6d8ac 100644
--- a/TinyFrame/TinyFrame.c
+++ b/TinyFrame/TinyFrame.c
@@ -537,6 +537,7 @@ void _TF_FN TF_AcceptChar(TinyFrame *tf, unsigned char c)
                 }
 
                 if (tf->len == 0) {
+                    // if the message has no body, we're done.
                     TF_HandleReceivedMessage(tf);
                     TF_ResetParser(tf);
                     break;
@@ -773,16 +774,19 @@ static bool _TF_FN TF_SendFrame(TinyFrame *tf, TF_Msg *msg, TF_Listener listener
         }
     }
 
-    // Flush if checksum wouldn't fit in the buffer
-    if (TF_SENDBUF_LEN - len < sizeof(TF_CKSUM)) {
-        TF_WriteImpl(tf, (const uint8_t *) tf->sendbuf, len);
-        len = 0;
+    // Checksum only if message had a body
+    if (msg->len > 0) {
+        // Flush if checksum wouldn't fit in the buffer
+        if (TF_SENDBUF_LEN - len < sizeof(TF_CKSUM)) {
+            TF_WriteImpl(tf, (const uint8_t *) tf->sendbuf, len);
+            len = 0;
+        }
+
+        // Add checksum, flush what remains to be sent
+        len += TF_ComposeTail(tf->sendbuf + len, &cksum);
     }
 
-    // Add checksum, flush what remains to be sent
-    len += TF_ComposeTail(tf->sendbuf+len, &cksum);
     TF_WriteImpl(tf, (const uint8_t *) tf->sendbuf, len);
-
     TF_ReleaseTx(tf);
 
     return true;
diff --git a/TinyFrame/TinyFrame.h b/TinyFrame/TinyFrame.h
index a4d92df..a588309 100644
--- a/TinyFrame/TinyFrame.h
+++ b/TinyFrame/TinyFrame.h
@@ -3,14 +3,14 @@
 
 /**
  * TinyFrame protocol library
- * 
- * (c) Ondřej Hruška 2017, MIT License 
+ *
+ * (c) Ondřej Hruška 2017, MIT License
  * no liability/warranty, free for any use, must retain this notice & license
- * 
+ *
  * Upstream URL: https://github.com/MightyPork/TinyFrame
  */
 
-#define TF_VERSION "2.0.1"
+#define TF_VERSION "2.0.3"
 
 //---------------------------------------------------------------------------
 #include <stdint.h>  // for uint8_t etc