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CommandStation-EX/DCCWaveform.cpp

281 lines
9.1 KiB
C++

/*
* © 2021 Neil McKechnie
* © 2021 Mike S
* © 2021 Fred Decker
* © 2020-2022 Harald Barth
* © 2020-2021 Chris Harlow
* All rights reserved.
*
* This file is part of CommandStation-EX
*
* This is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* It is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with CommandStation. If not, see <https://www.gnu.org/licenses/>.
*/
#ifndef ARDUINO_ARCH_ESP32
// This code is replaced entirely on an ESP32
#include <Arduino.h>
#include "DCCWaveform.h"
#include "TrackManager.h"
#include "DCCTimer.h"
#include "DCCACK.h"
#include "DIAG.h"
DCCWaveform DCCWaveform::mainTrack(PREAMBLE_BITS_MAIN, true);
DCCWaveform DCCWaveform::progTrack(PREAMBLE_BITS_PROG, false);
// This bitmask has 9 entries as each byte is trasmitted as a zero + 8 bits.
const byte bitMask[] = {0x00, 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01};
const byte idlePacket[] = {0xFF, 0x00, 0xFF};
const byte resetPacket[] = {0x00, 0x00, 0x00};
// For each state of the wave nextState=stateTransform[currentState]
const WAVE_STATE stateTransform[]={
/* WAVE_START -> */ WAVE_PENDING,
/* WAVE_MID_1 -> */ WAVE_START,
/* WAVE_HIGH_0 -> */ WAVE_MID_0,
/* WAVE_MID_0 -> */ WAVE_LOW_0,
/* WAVE_LOW_0 -> */ WAVE_START,
/* WAVE_PENDING (should not happen) -> */ WAVE_PENDING};
// For each state of the wave, signal pin is HIGH or LOW
const bool signalTransform[]={
/* WAVE_START -> */ HIGH,
/* WAVE_MID_1 -> */ LOW,
/* WAVE_HIGH_0 -> */ HIGH,
/* WAVE_MID_0 -> */ LOW,
/* WAVE_LOW_0 -> */ LOW,
/* WAVE_PENDING (should not happen) -> */ LOW};
void DCCWaveform::begin() {
DCCTimer::begin(DCCWaveform::interruptHandler);
}
void DCCWaveform::loop() {
// empty placemarker in case ESP32 needs something here
}
#pragma GCC push_options
#pragma GCC optimize ("-O3")
void DCCWaveform::interruptHandler() {
// call the timer edge sensitive actions for progtrack and maintrack
// member functions would be cleaner but have more overhead
byte sigMain=signalTransform[mainTrack.state];
byte sigProg=TrackManager::progTrackSyncMain? sigMain : signalTransform[progTrack.state];
// Set the signal state for both tracks
TrackManager::setDCCSignal(sigMain);
TrackManager::setPROGSignal(sigProg);
// Refresh the values in the ADCee object buffering the values of the ADC HW
ADCee::scan();
// Move on in the state engine
mainTrack.state=stateTransform[mainTrack.state];
progTrack.state=stateTransform[progTrack.state];
// WAVE_PENDING means we dont yet know what the next bit is
if (mainTrack.state==WAVE_PENDING) mainTrack.interrupt2();
if (progTrack.state==WAVE_PENDING) progTrack.interrupt2();
else DCCACK::checkAck(progTrack.getResets());
}
#pragma GCC pop_options
// An instance of this class handles the DCC transmissions for one track. (main or prog)
// Interrupts are marshalled via the statics.
// A track has a current transmit buffer, and a pending buffer.
// When the current buffer is exhausted, either the pending buffer (if there is one waiting) or an idle buffer.
DCCWaveform::DCCWaveform( byte preambleBits, bool isMain) {
isMainTrack = isMain;
packetPending = false;
memcpy(transmitPacket, idlePacket, sizeof(idlePacket));
state = WAVE_START;
// The +1 below is to allow the preamble generator to create the stop bit
// for the previous packet.
requiredPreambles = preambleBits+1;
bytes_sent = 0;
bits_sent = 0;
}
#pragma GCC push_options
#pragma GCC optimize ("-O3")
void DCCWaveform::interrupt2() {
// calculate the next bit to be sent:
// set state WAVE_MID_1 for a 1=bit
// or WAVE_HIGH_0 for a 0 bit.
if (remainingPreambles > 0 ) {
state=WAVE_MID_1; // switch state to trigger LOW on next interrupt
remainingPreambles--;
// Update free memory diagnostic as we don't have anything else to do this time.
// Allow for checkAck and its called functions using 22 bytes more.
DCCTimer::updateMinimumFreeMemoryISR(22);
return;
}
// Wave has gone HIGH but what happens next depends on the bit to be transmitted
// beware OF 9-BIT MASK generating a zero to start each byte
state=(transmitPacket[bytes_sent] & bitMask[bits_sent])? WAVE_MID_1 : WAVE_HIGH_0;
bits_sent++;
// If this is the last bit of a byte, prepare for the next byte
if (bits_sent == 9) { // zero followed by 8 bits of a byte
//end of Byte
bits_sent = 0;
bytes_sent++;
// if this is the last byte, prepere for next packet
if (bytes_sent >= transmitLength) {
// end of transmission buffer... repeat or switch to next message
bytes_sent = 0;
remainingPreambles = requiredPreambles;
if (transmitRepeats > 0) {
transmitRepeats--;
}
else if (packetPending) {
// Copy pending packet to transmit packet
// a fixed length memcpy is faster than a variable length loop for these small lengths
// for (int b = 0; b < pendingLength; b++) transmitPacket[b] = pendingPacket[b];
memcpy( transmitPacket, pendingPacket, sizeof(pendingPacket));
transmitLength = pendingLength;
transmitRepeats = pendingRepeats;
packetPending = false;
clearResets();
}
else {
// Fortunately reset and idle packets are the same length
memcpy( transmitPacket, isMainTrack ? idlePacket : resetPacket, sizeof(idlePacket));
transmitLength = sizeof(idlePacket);
transmitRepeats = 0;
if (getResets() < 250) sentResetsSincePacket++; // only place to increment (private!)
}
}
}
}
#pragma GCC pop_options
// Wait until there is no packet pending, then make this pending
void DCCWaveform::schedulePacket(const byte buffer[], byte byteCount, byte repeats) {
if (byteCount > MAX_PACKET_SIZE) return; // allow for chksum
while (packetPending);
byte checksum = 0;
for (byte b = 0; b < byteCount; b++) {
checksum ^= buffer[b];
pendingPacket[b] = buffer[b];
}
// buffer is MAX_PACKET_SIZE but pendingPacket is one bigger
pendingPacket[byteCount] = checksum;
pendingLength = byteCount + 1;
pendingRepeats = repeats;
packetPending = true;
clearResets();
}
bool DCCWaveform::getPacketPending() {
return packetPending;
}
#endif
#ifdef ARDUINO_ARCH_ESP32
#include "DCCWaveform.h"
#include "DCCACK.h"
DCCWaveform DCCWaveform::mainTrack(PREAMBLE_BITS_MAIN, true);
DCCWaveform DCCWaveform::progTrack(PREAMBLE_BITS_PROG, false);
RMTChannel *DCCWaveform::rmtMainChannel = NULL;
RMTChannel *DCCWaveform::rmtProgChannel = NULL;
DCCWaveform::DCCWaveform(byte preambleBits, bool isMain) {
isMainTrack = isMain;
requiredPreambles = preambleBits;
}
void DCCWaveform::begin() {
for(const auto& md: TrackManager::getMainDrivers()) {
pinpair p = md->getSignalPin();
if(rmtMainChannel) {
//DIAG(F("added pins %d %d to MAIN channel"), p.pin, p.invpin);
rmtMainChannel->addPin(p); // add pin to existing main channel
} else {
//DIAG(F("new MAIN channel with pins %d %d"), p.pin, p.invpin);
rmtMainChannel = new RMTChannel(p, true); /* create new main channel */
}
}
MotorDriver *md = TrackManager::getProgDriver();
if (md) {
pinpair p = md->getSignalPin();
if (rmtProgChannel) {
//DIAG(F("added pins %d %d to PROG channel"), p.pin, p.invpin);
rmtProgChannel->addPin(p); // add pin to existing prog channel
} else {
//DIAG(F("new PROGchannel with pins %d %d"), p.pin, p.invpin);
rmtProgChannel = new RMTChannel(p, false);
}
}
}
void DCCWaveform::schedulePacket(const byte buffer[], byte byteCount, byte repeats) {
if (byteCount > MAX_PACKET_SIZE) return; // allow for chksum
byte checksum = 0;
for (byte b = 0; b < byteCount; b++) {
checksum ^= buffer[b];
pendingPacket[b] = buffer[b];
}
// buffer is MAX_PACKET_SIZE but pendingPacket is one bigger
pendingPacket[byteCount] = checksum;
pendingLength = byteCount + 1;
pendingRepeats = repeats;
// The resets will be zero not only now but as well repeats packets into the future
clearResets(repeats+1);
{
int ret;
do {
if(isMainTrack) {
if (rmtMainChannel != NULL)
ret = rmtMainChannel->RMTfillData(pendingPacket, pendingLength, pendingRepeats);
} else {
if (rmtProgChannel != NULL)
ret = rmtProgChannel->RMTfillData(pendingPacket, pendingLength, pendingRepeats);
}
} while(ret > 0);
}
}
bool DCCWaveform::getPacketPending() {
if(isMainTrack) {
if (rmtMainChannel == NULL)
return true;
return rmtMainChannel->busy();
} else {
if (rmtProgChannel == NULL)
return true;
return rmtProgChannel->busy();
}
}
void IRAM_ATTR DCCWaveform::loop() {
DCCACK::checkAck(progTrack.getResets());
}
#endif