Files
DCC_Decoder/DCC_Decoder.h
2015-04-13 11:03:32 -07:00

207 lines
8.6 KiB
C++

//
// DCC_Decoder.h - Arduino library for NMRA DCC Decoding.
// Written by Kevin Snow, MynaBay.com, November, 2011.
// Questions: dcc@mynabay.com
// Released into the public domain.
//
#ifndef __DCC_DECODER_H__
#define __DCC_DECODER_H__
#include "Arduino.h"
///////////////////////////////////////////////////////////////////////////////////////
#define kDCC_STOP_SPEED 0xFE
#define kDCC_ESTOP_SPEED 0xFF
// Multifunction Decoders
#define kCV_PrimaryAddress 1
#define kCV_Vstart 2
#define kCV_AccelerationRate 3
#define kCV_Deceleration Rate 4
#define kCV_ManufacturerVersionNo 7
#define kCV_ManufacturedID 8
#define kCV_ExtendedAddress1 17
#define kCV_ExtendedAddress2 18
#define kCV_ConfigurationData1 29
// Accessory Decoders
#define kCV_AddressLSB 1
#define kCV_AddressMSB 9
// DCC_Decoder results/errors
#define kDCC_OK 0
#define kDCC_OK_UNHANDLED 1
#define kDCC_OK_BOOT 2
#define kDCC_OK_IDLE 3
#define kDCC_OK_RESET 4
#define kDCC_OK_RAW 5
#define kDCC_OK_BASELINE 6
#define kDCC_OK_BASIC_ACCESSORY 7
#define kDCC_OK_EXTENDED_ACCESSORY 8
#define kDCC_OK_MAX 99
#define kDCC_ERR_DETECTION_FAILED 100
#define kDCC_ERR_BASELINE_ADDR 101
#define kDCC_ERR_BASELINE_INSTR 102 // Baseline packet instruction isn't 0x01DCSSSS
#define kDCC_ERR_MISSED_BITS 103
#define kDCC_ERR_NOT_0_OR_1 104
#define kDCC_ERR_INVALID_LENGTH 105
#define kDCC_ERR_MISSING_END_BIT 106
// Min and max valid packet lengths
#define kPACKET_LEN_MIN 3
#define kPACKET_LEN_MAX 6
// CV 1..256 are supported
#define kCV_MAX 257
///////////////////////////////////////////////////////////////////////////////////////
typedef boolean (*RawPacket)(byte byteCount, byte* packetBytes);
typedef void (*IdleResetPacket)(byte byteCount, byte* packetBytes);
typedef void (*BaselineControlPacket)(int address, int speed, int direction);
typedef void (*BasicAccDecoderPacket)(int address, boolean activate, byte data);
typedef void (*ExtendedAccDecoderPacket)(int address, byte data);
typedef void (*DecodingEngineCompletion)(byte resultOfLastPacket);
///////////////////////////////////////////////////////////////////////////////////////
typedef void(*StateFunc)();
///////////////////////////////////////////////////////////////////////////////////////
class DCC_Decoder
{
public:
DCC_Decoder();
// Called from setup in Arduino Sketch. Set mfgID, mfgVers and interrupt. Call one SetupXXX
void SetupDecoder(byte mfgID, byte mfgVers, byte interrupt); // Used for Decoder
void SetupMonitor(byte interrupt); // Used when building a monitor
// All packets are sent to RawPacketHandler. Return true to stop dispatching to other handlers.
void SetRawPacketHandler(RawPacket func);
// S 9.2 defines two special packets. Idle and reset.
void SetIdlePacketHandler(IdleResetPacket func);
void SetResetPacketHandler(IdleResetPacket func);
// Handler for S 9.2 baseline packets. Speed value will be 1-14, 1-28, kDCC_STOP_SPEED or kDCC_ESTOP_SPEED
void SetBaselineControlPacketHandler(BaselineControlPacket func, boolean allPackets);
// Handler for RP 9.2.1 Accessory Decoders.
void SetBasicAccessoryDecoderPacketHandler(BasicAccDecoderPacket func, boolean allPackets);
void SetExtendedAccessoryDecoderPacketHandler(ExtendedAccDecoderPacket func, boolean allPackets);
// Read/Write CVs
byte ReadCV(int cv);
void WriteCV(int cv, byte data);
// Helper function to read decoder address
int Address();
// Call at least once from mainloop. Not calling frequently enough and library will miss data bits!
void loop();
// Returns the packet data in string form.
char* MakePacketString(char* buffer60Bytes, byte packetByteCount, byte* packet);
// Returns the number of bits in last preamble
int LastPreambleBitCount();
// Timing functions. These return MS since various packets
unsigned long MillisecondsSinceLastValidPacket();
unsigned long MillisecondsSinceLastPacketToThisDecoder();
unsigned long MillisecondsSinceLastIdlePacket();
unsigned long MillisecondsSinceLastResetPacket();
//======================= Debugging =======================//
// Everytime the DCC Decoder engine starts looking for preamble bits this will be
// called with result of last packet. (Debugging)
void SetDecodingEngineCompletionStatusHandler(DecodingEngineCompletion func);
// Converts code passed into completionStatusHandler to human readable string.
const char PROGMEM* ResultString(byte resultCode);
//======================= Library Internals =======================//
private:
// State machine functions
static void State_Boot();
static void State_ReadPreamble();
static void State_ReadPacket();
static void State_Execute();
static void State_Reset();
// Function pointers for the library callbacks
static RawPacket func_RawPacket;
static IdleResetPacket func_IdlePacket;
static IdleResetPacket func_ResetPacket;
static BasicAccDecoderPacket func_BasicAccPacket;
static boolean func_BasicAccPacket_All_Packets;
static ExtendedAccDecoderPacket func_ExtdAccPacket;
static boolean func_ExtdAccPacket_All_Packets;
static BaselineControlPacket func_BaselineControlPacket;
static boolean func_BaselineControlPacket_All_Packets;
static DecodingEngineCompletion func_DecodingEngineCompletion;
// Current state function pointer
static StateFunc gState; // Current state function pointer
// Timing data from last interrupt
static unsigned int gLastChaos; // Interrupt chaos count we processed
// Preamble bit count
static int gPreambleCount; // Bit count for reading preamble
// Reset reason
static byte gResetReason; // Result code of last reason decoder was reset
static boolean gHandledAsRawPacket;
// Packet data
static byte gPacket[kPACKET_LEN_MAX]; // The packet data.
static byte gPacketIndex; // Byte index to write to.
static byte gPacketMask; // Bit index to write to. 0x80,0x40,0x20,...0x01
static boolean gPacketEndedWith1; // Set true if packet ended on 1. Spec requires that the
// packet end bit can count as a bit in next preamble.
// CV Storage
static byte gCV[kCV_MAX]; // CV Storage (TODO - Storage in PROGMEM)
// Packet arrival timing
static unsigned long gThisPacketMS; // Milliseconds of this packet being parsed
static boolean gLastPacketToThisAddress; // Was last pack processed to this decoder's address?
static unsigned long gLastValidPacketMS; // Milliseconds of last valid packet
static unsigned long gLastValidPacketToAddressMS; // Milliseconds of last valid packet to this decoder
static unsigned long gLastValidIdlePacketMS; // Milliseconds of last valid idle packet
static unsigned long gLastValidResetPacketMS; // Milliseconds of last valid reset packet
//////////////////////////////////////////////////////
// Interrupt Support
static void StartInterrupt(byte interrupt);
static void DCC_Interrupt();
static void ShiftInterruptAlignment();
static unsigned long gInterruptMicros;
static byte gInterruptTimeIndex;
static volatile unsigned int gInterruptTime[2];
static volatile unsigned int gInterruptChaos;
};
///////////////////////////////////////////////////////////////////////////////////////
extern DCC_Decoder DCC;
///////////////////////////////////////////////////////////////////////////////////////
#endif