Add functions to expose the RX/TX error counters

This exposes the REC and TEC registers. They hold the error counters and can give insides before the checkError triggers.

Author: designer2k2

mcp2515.cpp

@@ -754,3 +754,13 @@ void MCP2515::clearERRIF()
     //clearInterrupts();
     modifyRegister(MCP_CANINTF, CANINTF_ERRIF, 0);
 }
+
+uint8_t MCP2515::errorCountRX(void)                             
+{
+    return readRegister(MCP_REC);
+}
+
+uint8_t MCP2515::errorCountTX(void)                             
+{
+    return readRegister(MCP_TEC);
+}

mcp2515.h

@@ -488,6 +488,8 @@ class MCP2515
         void clearRXnOVR(void);
         void clearMERR();
         void clearERRIF();
+        uint8_t errorCountRX(void);
+        uint8_t errorCountTX(void);
 };
 
 #endif