From 5c1392db30aabed7a17de33342cf93e3f5836449 Mon Sep 17 00:00:00 2001
From: BykeBlast <luigi.balestrini@gmail.com>
Date: Mon, 1 Sep 2014 13:36:01 +0200
Subject: [PATCH] Update mcp_can.cpp

- Added: buffer limit in mcp2515_readRegisterS
- Added: return code check in readMsgBuf
- Added: function readMsgBufID to read message and object id in a single phase
---
 mcp_can.cpp | 43 +++++++++++++++++++++++++++++++++++--------
 1 file changed, 35 insertions(+), 8 deletions(-)

diff --git a/mcp_can.cpp b/mcp_can.cpp
index 9e7137d..580cf10 100644
--- a/mcp_can.cpp
+++ b/mcp_can.cpp
@@ -65,8 +65,7 @@ void MCP_CAN::mcp2515_readRegisterS(const INT8U address, INT8U values[], const I
 	spi_readwrite(MCP_READ);
 	spi_readwrite(address);
 	// mcp2515 has auto-increment of address-pointer
-	for (i=0; i<n; i++) 
-    {
+	for (i=0; i<n && i<CAN_MAX_CHAR_IN_MESSAGE; i++) {
 		values[i] = spi_read();
 	}
 	MCP2515_UNSELECT();
@@ -761,12 +760,40 @@ INT8U MCP_CAN::readMsg()
 *********************************************************************************************************/
 INT8U MCP_CAN::readMsgBuf(INT8U *len, INT8U buf[])
 {
-    readMsg();
-    *len = m_nDlc;
-    for(int i = 0; i<m_nDlc; i++)
-    {
-      buf[i] = m_nDta[i];
+    INT8U  rc;
+    
+    rc = readMsg();
+    
+    if (rc == CAN_OK) {
+       *len = m_nDlc;
+       for(int i = 0; i<m_nDlc; i++) {
+         buf[i] = m_nDta[i];
+       } 
+    } else {
+       	 *len = 0;
     }
+    return rc;
+}
+
+/*********************************************************************************************************
+** Function name:           readMsgBufID
+** Descriptions:            read message buf and can bus source ID
+*********************************************************************************************************/
+INT8U MCP_CAN::readMsgBufID(INT32U *ID, INT8U *len, INT8U buf[])
+{
+    INT8U rc;
+    rc = readMsg();
+
+    if (rc == CAN_OK) {
+       *len = m_nDlc;
+       *ID  = m_nID;
+       for(int i = 0; i<m_nDlc && i < MAX_CHAR_IN_MESSAGE; i++) {
+          buf[i] = m_nDta[i];
+       }
+    } else {
+       *len = 0;
+    }
+    return rc;
 }
 
 /*********************************************************************************************************
@@ -815,4 +842,4 @@ INT32U MCP_CAN::getCanId(void)
 }
 /*********************************************************************************************************
   END FILE
-*********************************************************************************************************/
\ No newline at end of file
+*********************************************************************************************************/