initial commit

DCCPacket.cpp

@@ -0,0 +1,60 @@
+#include "DCCPacket.h"
+
+
+DCCPacket::DCCPacket(unsigned int decoder_address) : address(decoder_address), size(1), kind(idle_packet_kind), repeat(0)
+{
+  data[0] = 0xFF; //is this really the idle packet? TODO
+}
+
+byte DCCPacket::getBitstream(byte rawbytes[]) //returns size of array.
+{
+  int total_size = 1; //minimum size
+  //Serial.print("Address: ");
+  if(address < 127) //TODO IS THIS RIGHT?
+  {
+    rawbytes[0] = (byte)address;
+    //Serial.println(rawbytes[0],BIN);
+  }
+  else //ELSE WHAT?
+  {
+    rawbytes[0] = (byte)address >> 8;
+    rawbytes[1] = (byte)(address & 0xFF);
+    //Serial.print(rawbytes[0],BIN);
+    //Serial.print(" ");
+    //Serial.println(rawbytes[1],BIN);
+    ++total_size;
+  }
+  int i;
+  //Serial.print("Payload:");
+  for(i = 0; i < size; ++i,++total_size)
+  {
+    rawbytes[total_size] = data[i];
+    //Serial.print(" ");
+    //Serial.print(rawbytes[total_size],BIN);
+  }
+  //Serial.println("");
+  //Serial.print("XOR: ");
+  //Serial.print(total_size);
+  //Serial.print(" ");
+  byte XOR = 0;
+  for(i = 0; i < total_size; ++i)
+  {
+    XOR ^= rawbytes[i];
+  }
+  rawbytes[total_size] = XOR;
+  //Serial.println(rawbytes[total_size],BIN);
+
+  return total_size+1;  
+}
+
+byte DCCPacket::getSize(void)
+{
+  return size;
+}
+
+byte DCCPacket::addData(byte data[], byte size) //insert freeform data.
+{
+  for(int i = 0; i < size; ++i)
+    data[i] = data[i];
+  size = size;
+}

DCCPacket.h

@@ -0,0 +1,42 @@
+#ifndef __DCCPACKET_H__
+#define __DCCPACKET_H__
+
+#include "WProgram.h"
+
+//Packet kinds
+enum packet_kind_t {
+  idle_packet_kind,
+  e_stop_packet_kind,
+  speed_packet_kind,
+  function_packet_kind,
+  accessory_packet_kind,
+  reset_packet_kind,
+  other_packe_kind
+};
+
+class DCCPacket
+{
+   //A DCC packet is at most 6 bytes: 2 of address, three of data, one of XOR
+    unsigned int address;// = 0;
+    byte data[3];// = {0,0,0};
+    byte size;// = 3; //of data only
+//    byte XOR;// = 0;
+    byte repeat;
+    packet_kind_t kind;
+
+//    void computeXOR(void);
+  public:
+    DCCPacket(unsigned int address=0);
+
+    byte getBitstream(byte rawbytes[]); //returns size of array.
+    byte getSize(void);
+    inline unsigned int getAddress(void) { return address; }
+    inline void setAddress(unsigned int new_address) { address = new_address; }
+    byte addData(byte data[], byte size); //insert freeform data.
+    inline void setKind(packet_kind_t new_kind) { kind = new_kind; }
+    inline packet_kind_t getKind(void) { return kind; }
+    inline void setRepeat(byte new_repeat) { repeat = new_repeat; }
+    inline byte getRepeat(void) { return repeat; }
+};
+
+#endif //__DCCPACKET_H__