1
0
mirror of https://github.com/DCC-EX/CommandStation-EX.git synced 2024-11-27 01:56:14 +01:00
CommandStation-EX/DCC.cpp
2020-05-26 18:34:54 +01:00

207 lines
7.1 KiB
C++

#include "DCC.h"
#include "DCCWaveform.h"
#include "DIAG.h"
// This module is responsible for converting API calls into
// messages to be sent to the waveform generator.
// It has no visibility of the hardware, timers, interrupts
// nor of the waveform issues such as preambles, start bits checksums or cutouts.
//
// Nor should it have to deal with JMRI responsess other than the OK/FAIL
// or cv value returned. I will move that back to the JMRI interface later
//
// The interface to the waveform generator is narrowed down to merely:
// Scheduling a message on the prog or main track using a function
// Obtaining ACKs from the prog track using a function
// There are no volatiles here.
void DCC::begin() {
DCCWaveform::begin();
}
void DCC::setThrottle( uint16_t cab, uint8_t tSpeed, bool tDirection) {
setThrottle2(cab, tSpeed, tDirection);
// retain speed for loco reminders
updateLocoReminder(cab, tSpeed, tDirection );
}
void DCC::setThrottle2( uint16_t cab, uint8_t tSpeed, bool tDirection) {
uint8_t b[5];
uint8_t nB = 0;
if (cab > 127)
b[nB++] = highByte(cab) | 0xC0; // convert train number into a two-byte address
b[nB++] = lowByte(cab);
b[nB++] = 0x3F; // 128-step speed control byte
if (tSpeed > 0)
b[nB++] = tSpeed + (tSpeed > 0) + tDirection * 128; // max speed is 126, but speed codes range from 2-127 (0=stop, 1=emergency stop)
else {
b[nB++] = 1;
tSpeed = 0;
}
DCCWaveform::mainTrack.schedulePacket(b, nB, 0);
}
void DCC::setFunction(int cab, byte byte1) {
uint8_t b[4];
uint8_t nB = 0;
if (cab > 127)
b[nB++] = highByte(cab) | 0xC0; // convert train number into a two-byte address
b[nB++] = lowByte(cab);
b[nB++] = (byte1 | 0x80) & 0xBF;
DCCWaveform::mainTrack.schedulePacket(b, nB, 4); // Repeat the packet four times
}
void DCC::setFunction(int cab, byte byte1, byte byte2) {
byte b[5];
byte nB = 0;
if (cab > 127)
b[nB++] = highByte(cab) | 0xC0; // convert train number into a two-byte address
b[nB++] = lowByte(cab);
b[nB++] = (byte1 | 0xDE) & 0xDF; // for safety this guarantees that first byte will either be 0xDE (for F13-F20) or 0xDF (for F21-F28)
b[nB++] = byte2;
DCCWaveform::mainTrack.schedulePacket(b, nB, 4); // Repeat the packet four times
}
void DCC::setAccessory(int address, byte number, bool activate) {
byte b[3]; // save space for checksum byte
b[0] = address % 64 + 128; // first byte is of the form 10AAAAAA, where AAAAAA represent 6 least signifcant bits of accessory address
b[1] = ((((address / 64) % 8) << 4) + (number % 4 << 1) + activate % 2) ^ 0xF8; // second byte is of the form 1AAACDDD, where C should be 1, and the least significant D represent activate/deactivate
DCCWaveform::mainTrack.schedulePacket(b, 2, 4); // Repeat the packet four times
}
void DCC::writeCVByteMain(int cab, int cv, byte bValue) {
byte b[6]; // save space for checksum byte
byte nB = 0;
if (cab > 127)
b[nB++] = highByte(cab) | 0xC0; // convert train number into a two-byte address
b[nB++] = lowByte(cab);
b[nB++] = cv1(0xEC, cv); // any CV>1023 will become modulus(1024) due to bit-mask of 0x03
b[nB++] = cv2(cv);
b[nB++] = bValue;
DCCWaveform::mainTrack.schedulePacket(b, nB, 4);
}
void DCC::writeCVBitMain(int cab, int cv, byte bNum, bool bValue) {
byte b[6]; // save space for checksum byte
byte nB = 0;
bValue = bValue % 2;
bNum = bNum % 8;
if (cab > 127)
b[nB++] = highByte(cab) | 0xC0; // convert train number into a two-byte address
b[nB++] = lowByte(cab);
b[nB++] = cv1(0xE8, cv); // any CV>1023 will become modulus(1024) due to bit-mask of 0x03
b[nB++] = cv2(cv);
b[nB++] = 0xF0 + bValue * 8 + bNum;
DCCWaveform::mainTrack.schedulePacket(b, nB, 4);
}
bool DCC::writeCVByte(int cv, byte bValue) {
uint8_t message[] = {cv1(0x7C, cv), cv2(cv), bValue};
DCCWaveform::progTrack.schedulePacket(message, sizeof(message), 6); // NMRA recommends 6 write or reset packets for decoder recovery time
return verifyCV(cv, bValue);
}
bool DCC::writeCVBit(int cv, byte bNum, bool bValue) {
bValue = bValue % 2;
bNum = bNum % 8;
uint8_t message[] = {cv1(0x78, cv), cv2(cv), 0xF0 + bValue * 8 + bNum};
DCCWaveform::progTrack.schedulePacket(message, sizeof(message), 6); // NMRA recommends 6 write or reset packets for decoder recovery time
/* TODO... what is the verify opcode here?
bitWrite(message[2],4,1); // change instruction code from Write Bit to Verify Bit
DCCWaveform::progTrack.schedulePacket(message,sizeof(message),6); // NMRA recommends 6 write or reset packets for decoder recovery time
*/
return true; // <<<< NOT ACCURATE... see comment above
}
int DCC::readCV(int cv) {
byte message[] = { cv1(0x78, cv) , // any CV>1023 will become modulus(1024) due to bit-mask of 0x03
cv2(cv),
0
}; // trailing zero will be updated in loop below
byte value = 0;
// get each bit individually
for (int i = 0; i < 8; i++) {
message[2] = 0xE8 + i;
bool one=DCCWaveform::progTrack.schedulePacketWithAck(message, sizeof(message), 4); // NMRA recommends 5 read packets
value += one << i;
}
return verifyCV(cv, value) ? value : -1;
}
void DCC::loop() {
DCCWaveform::loop(); // powwer overload checks
// if the main track transmitter still has a pending packet, skip this loop.
if ( DCCWaveform::mainTrack.packetPending) return;
// each time around the Arduino loop, we resend a loco speed packet reminder
for (; nextLoco < MAX_LOCOS; nextLoco++) {
if (speedTable[nextLoco].loco > 0) {
setThrottle2(speedTable[nextLoco].loco, speedTable[nextLoco].speed, speedTable[nextLoco].forward);
nextLoco++;
return;
}
}
for (nextLoco = 0; nextLoco < MAX_LOCOS; nextLoco++) {
if (speedTable[nextLoco].loco > 0) {
setThrottle2(speedTable[nextLoco].loco, speedTable[nextLoco].speed, speedTable[nextLoco].forward);
nextLoco++;
return;
}
}
}
///// Private helper functions below here /////////////////////
byte DCC::cv1(byte opcode, int cv) {
cv--;
return (highByte(cv) & (byte)0x03) | opcode;
}
byte DCC::cv2(int cv) {
cv--;
return lowByte(cv);
}
bool DCC::verifyCV(int cv, byte value) {
byte message[] = { cv1(0x74, cv), cv2(cv), value};
DIAG(F("\n\nVerifying cv %d = %d"), cv, value);
return DCCWaveform::progTrack.schedulePacketWithAck(message, sizeof(message), 5);
}
void DCC::updateLocoReminder(int loco, byte tSpeed, bool forward) {
// determine speed reg for this loco
int reg;
int firstEmpty = MAX_LOCOS;
for (reg = 0; reg < MAX_LOCOS; reg++) {
if (speedTable[reg].loco == loco) break;
if (speedTable[reg].loco == 0 && firstEmpty == MAX_LOCOS) firstEmpty = reg;
}
if (reg == MAX_LOCOS) reg = firstEmpty;
if (reg >= MAX_LOCOS) {
DIAG(F("\nToo many locos\n"));
return;
}
speedTable[reg].loco = loco;
speedTable[reg].speed = tSpeed;
speedTable[reg].forward = forward;
}
DCC::LOCO DCC::speedTable[MAX_LOCOS];
int DCC::nextLoco = 0;