Fix Wire and add test with RTC

cores/validation/validation_I2C_RTC/build_as6/test.atsln

+
+Microsoft Visual Studio Solution File, Format Version 11.00
+# Atmel Studio Solution File, Format Version 11.00
+Project("{E66E83B9-2572-4076-B26E-6BE79FF3018A}") = "test", "test.cppproj", "{B3F859AD-E162-4C2F-9684-EAC6932FEC80}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|ARM = Debug|ARM
+		Release|ARM = Release|ARM
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{B3F859AD-E162-4C2F-9684-EAC6932FEC80}.Debug|ARM.ActiveCfg = Debug|ARM
+		{B3F859AD-E162-4C2F-9684-EAC6932FEC80}.Debug|ARM.Build.0 = Debug|ARM
+		{B3F859AD-E162-4C2F-9684-EAC6932FEC80}.Release|ARM.ActiveCfg = Release|ARM
+		{B3F859AD-E162-4C2F-9684-EAC6932FEC80}.Release|ARM.Build.0 = Release|ARM
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal

cores/validation/validation_I2C_RTC/test.cpp

+#include "Arduino.h"
+#include <Wire.h>
+
+const uint8_t address = 0x68;
+
+uint8_t decToBcd(byte val)
+{
+  return ( (val/10*16) + (val%10) );
+}
+
+// Convert binary coded decimal to normal decimal numbers
+uint8_t bcdToDec(byte val)
+{
+  return ( (val/16*10) + (val%16) );
+}
+
+void setup()
+{
+  Serial5.begin(9600);
+  Serial5.println("Wire init");
+  Wire.begin();
+
+  // Setting the date
+  /*
+  Wire.beginTransmission(address);
+    Wire.write((uint8_t)0x00);  // Init register
+    
+    Wire.write(decToBcd(0));  // Second
+    Wire.write(decToBcd(39));  // Minute
+    Wire.write(decToBcd(11));  // Hours
+    
+    Wire.write(decToBcd(4));  // Day of week
+
+    Wire.write(decToBcd(21));  // Day of Month
+    Wire.write(decToBcd(5));  // Month
+    Wire.write(decToBcd(14));  // Year
+  Wire.endTransmission();
+  */
+}
+
+void loop()
+{
+
+  Wire.beginTransmission(address);
+    Wire.write((uint8_t)0x3F);
+  Wire.endTransmission();
+
+  delay(10);
+
+  Wire.requestFrom(address, 7);
+/*  while(Wire.available())
+  {
+    Serial5.print(bcdToDec(Wire.read()));
+    Serial5.print(" ");
+  }
+  Serial5.println();*/
+
+  
+   int second     = bcdToDec(Wire.read() & 0x7f);
+   int minute     = bcdToDec(Wire.read());
+   int hour       = bcdToDec(Wire.read() & 0x3f);  // Need to change this if 12 hour am/pm
+   int dayOfWeek  = bcdToDec(Wire.read());
+   int dayOfMonth = bcdToDec(Wire.read());
+   int month      = bcdToDec(Wire.read());
+   int year       = bcdToDec(Wire.read());
+   
+   Serial5.print(hour, DEC);
+   Serial5.print(":");
+   Serial5.print(minute, DEC);
+   Serial5.print(":");
+   Serial5.print(second, DEC);
+   Serial5.print("  ");
+   Serial5.print(month, DEC);
+   Serial5.print("/");
+   Serial5.print(dayOfMonth, DEC);
+   Serial5.print("/");
+   Serial5.print(year,DEC);
+   Serial5.print("  ");
+   Serial5.println();
+
+  delay(990);
+}

libraries/Wire/Wire.cpp

@@ -50,28 +50,28 @@ void TwoWire::begin(uint8_t address) {
 
 uint8_t TwoWire::requestFrom(uint8_t address, size_t quantity, bool stopBit)
 { 
-  size_t toRead = quantity;
+  size_t toRead = quantity + 1;
 
   if(sercom->startTransmissionWIRE(address, WIRE_READ_FLAG))
   {
     // Connected to slave
     while(toRead--)
+    //for(toRead = quantity; toRead >= 0; --toRead)
     {
-      if( toRead == 0)
+      if( toRead == 0)  // Stop transmission
       {
-        sercom->prepareNackBitWIRE();
+        sercom->prepareNackBitWIRE(); // Prepare NACK to stop slave transmission
+        sercom->readDataWIRE(); // Clear data register to send NACK
+        sercom->prepareCommandBitsWire(WIRE_MASTER_ACT_STOP); // Send Stop 
       }
-      else
+      else // Continue transmission
       {
-        sercom->prepareAckBitWIRE();
-        sercom->prepareCommandBitsWire(WIRE_MASTER_ACT_READ);
+        sercom->prepareAckBitWIRE();  // Prepare Acknowledge
+        sercom->prepareCommandBitsWire(WIRE_MASTER_ACT_READ); // Prepare the ACK command for the slave
+        rxBuffer.store_char( sercom->readDataWIRE() );  // Read data and send the ACK
       }
-
-      rxBuffer.store_char( sercom->readDataWIRE() );
     }
   }
-  
-  sercom->prepareCommandBitsWire(WIRE_MASTER_ACT_STOP);
 
   return quantity - toRead;
 }