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CommandStation-EX/DCCWaveform.cpp
2021-08-01 12:45:29 +02:00

365 lines
13 KiB
C++

/*
* © 2020, Chris Harlow. All rights reserved.
* © 2020, Harald Barth.
*
* This file is part of Asbelos DCC API
*
* 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/>.
*/
#include <Arduino.h>
#include "DCCWaveform.h"
#include "DCCTimer.h"
#include "DIAG.h"
#include "freeMemory.h"
DCCWaveform DCCWaveform::mainTrack(PREAMBLE_BITS_MAIN, true);
DCCWaveform DCCWaveform::progTrack(PREAMBLE_BITS_PROG, false);
bool DCCWaveform::progTrackSyncMain=false;
bool DCCWaveform::progTrackBoosted=false;
int DCCWaveform::progTripValue=0;
volatile uint8_t DCCWaveform::numAckGaps=0;
volatile uint8_t DCCWaveform::numAckSamples=0;
uint8_t DCCWaveform::trailingEdgeCounter=0;
void DCCWaveform::begin(MotorDriver * mainDriver, MotorDriver * progDriver) {
mainTrack.motorDriver=mainDriver;
progTrack.motorDriver=progDriver;
progTripValue = progDriver->mA2raw(TRIP_CURRENT_PROG); // need only calculate once hence static
mainTrack.setPowerMode(POWERMODE::OFF);
progTrack.setPowerMode(POWERMODE::OFF);
// Fault pin config for odd motor boards (example pololu)
MotorDriver::commonFaultPin = ((mainDriver->getFaultPin() == progDriver->getFaultPin())
&& (mainDriver->getFaultPin() != UNUSED_PIN));
// Only use PWM if both pins are PWM capable. Otherwise JOIN does not work
MotorDriver::usePWM= mainDriver->isPWMCapable() && progDriver->isPWMCapable();
DIAG(F("Signal pin config: %S accuracy waveform"),
MotorDriver::usePWM ? F("high") : F("normal") );
DCCTimer::begin(DCCWaveform::interruptHandler);
}
void DCCWaveform::loop(bool ackManagerActive) {
mainTrack.checkPowerOverload(false);
progTrack.checkPowerOverload(ackManagerActive);
}
#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=progTrackSyncMain? sigMain : signalTransform[progTrack.state];
// Set the signal state for both tracks
mainTrack.motorDriver->setSignal(sigMain);
progTrack.motorDriver->setSignal(sigProg);
// 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 if (progTrack.ackPending) progTrack.checkAck();
}
#pragma GCC push_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.
// 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};
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;
sampleDelay = 0;
lastSampleTaken = millis();
ackPending=false;
}
POWERMODE DCCWaveform::getPowerMode() {
return powerMode;
}
void DCCWaveform::setPowerMode(POWERMODE mode) {
powerMode = mode;
bool ison = (mode == POWERMODE::ON);
motorDriver->setPower( ison);
}
void DCCWaveform::checkPowerOverload(bool ackManagerActive) {
if (millis() - lastSampleTaken < sampleDelay) return;
lastSampleTaken = millis();
int tripValue= motorDriver->getRawCurrentTripValue();
if (!isMainTrack && !ackManagerActive && !progTrackSyncMain && !progTrackBoosted)
tripValue=progTripValue;
// Trackname for diag messages later
const FSH*trackname = isMainTrack ? F("MAIN") : F("PROG");
switch (powerMode) {
case POWERMODE::OFF:
sampleDelay = POWER_SAMPLE_OFF_WAIT;
break;
case POWERMODE::ON:
// Check current
lastCurrent=motorDriver->getCurrentRaw();
if (lastCurrent < 0) {
// We have a fault pin condition to take care of
lastCurrent = -lastCurrent;
setPowerMode(POWERMODE::OVERLOAD); // Turn off, decide later how fast to turn on again
if (MotorDriver::commonFaultPin) {
if (lastCurrent <= tripValue) {
setPowerMode(POWERMODE::ON); // maybe other track
}
// Write this after the fact as we want to turn on as fast as possible
// because we don't know which output actually triggered the fault pin
DIAG(F("COMMON FAULT PIN ACTIVE - TOGGLED POWER on %S"), trackname);
} else {
DIAG(F("%S FAULT PIN ACTIVE - OVERLOAD"), trackname);
if (lastCurrent < tripValue) {
lastCurrent = tripValue; // exaggerate
}
}
}
if (lastCurrent < tripValue) {
sampleDelay = POWER_SAMPLE_ON_WAIT;
if(power_good_counter<100)
power_good_counter++;
else
if (power_sample_overload_wait>POWER_SAMPLE_OVERLOAD_WAIT) power_sample_overload_wait=POWER_SAMPLE_OVERLOAD_WAIT;
} else {
setPowerMode(POWERMODE::OVERLOAD);
unsigned int mA=motorDriver->raw2mA(lastCurrent);
unsigned int maxmA=motorDriver->raw2mA(tripValue);
power_good_counter=0;
sampleDelay = power_sample_overload_wait;
DIAG(F("%S TRACK POWER OVERLOAD current=%d max=%d offtime=%d"), trackname, mA, maxmA, sampleDelay);
if (power_sample_overload_wait >= 10000)
power_sample_overload_wait = 10000;
else
power_sample_overload_wait *= 2;
}
break;
case POWERMODE::OVERLOAD:
// Try setting it back on after the OVERLOAD_WAIT
setPowerMode(POWERMODE::ON);
sampleDelay = POWER_SAMPLE_ON_WAIT;
// Debug code....
DIAG(F("%S TRACK POWER RESET delay=%d"), trackname, sampleDelay);
break;
default:
sampleDelay = 999; // cant get here..meaningless statement to avoid compiler warning.
}
}
// For each state of the wave nextState=stateTransform[currentState]
const WAVE_STATE DCCWaveform::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 DCCWaveform::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};
#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.
updateMinimumFreeMemory(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;
sentResetsSincePacket=0;
}
else {
// Fortunately reset and idle packets are the same length
memcpy( transmitPacket, isMainTrack ? idlePacket : resetPacket, sizeof(idlePacket));
transmitLength = sizeof(idlePacket);
transmitRepeats = 0;
if (sentResetsSincePacket<250) sentResetsSincePacket++;
}
}
}
}
#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;
sentResetsSincePacket=0;
}
// Operations applicable to PROG track ONLY.
// (yes I know I could have subclassed the main track but...)
void DCCWaveform::setAckBaseline() {
if (isMainTrack) return;
int baseline=motorDriver->getCurrentRaw();
ackThreshold= baseline + motorDriver->mA2raw(ackLimitmA);
if (Diag::ACK) DIAG(F("ACK baseline=%d/%dmA Threshold=%d/%dmA Duration between %dus and %dus"),
baseline,motorDriver->raw2mA(baseline),
ackThreshold,motorDriver->raw2mA(ackThreshold),
minAckPulseDuration, maxAckPulseDuration);
}
void DCCWaveform::setAckPending() {
if (isMainTrack) return;
ackMaxCurrent=0;
ackPulseStart=0;
ackPulseDuration=0;
ackDetected=false;
ackCheckStart=millis();
numAckSamples=0;
numAckGaps=0;
ackPending=true; // interrupt routines will now take note
}
byte DCCWaveform::getAck() {
if (ackPending) return (2); // still waiting
if (Diag::ACK) DIAG(F("%S after %dmS max=%d/%dmA pulse=%duS samples=%d gaps=%d"),ackDetected?F("ACK"):F("NO-ACK"), ackCheckDuration,
ackMaxCurrent,motorDriver->raw2mA(ackMaxCurrent), ackPulseDuration, numAckSamples, numAckGaps);
if (ackDetected) return (1); // Yes we had an ack
return(0); // pending set off but not detected means no ACK.
}
#pragma GCC push_options
#pragma GCC optimize ("-O3")
void DCCWaveform::checkAck() {
// This function operates in interrupt() time so must be fast and can't DIAG
if (sentResetsSincePacket > 6) { //ACK timeout
ackCheckDuration=millis()-ackCheckStart;
ackPending = false;
return;
}
int current=motorDriver->getCurrentRaw();
numAckSamples++;
if (current > ackMaxCurrent) ackMaxCurrent=current;
// An ACK is a pulse lasting between minAckPulseDuration and maxAckPulseDuration uSecs (refer @haba)
if (current>ackThreshold) {
if (trailingEdgeCounter > 0) {
numAckGaps++;
trailingEdgeCounter = 0;
}
if (ackPulseStart==0) ackPulseStart=micros(); // leading edge of pulse detected
return;
}
// not in pulse
if (ackPulseStart==0) return; // keep waiting for leading edge
// if we reach to this point, we have
// detected trailing edge of pulse
if (trailingEdgeCounter == 0) {
ackPulseDuration=micros()-ackPulseStart;
}
// but we do not trust it yet and return (which will force another
// measurement) and first the third time around with low current
// the ack detection will be finalized.
if (trailingEdgeCounter < 2) {
trailingEdgeCounter++;
return;
}
trailingEdgeCounter = 0;
if (ackPulseDuration>=minAckPulseDuration && ackPulseDuration<=maxAckPulseDuration) {
ackCheckDuration=millis()-ackCheckStart;
ackDetected=true;
ackPending=false;
transmitRepeats=0; // shortcut remaining repeat packets
return; // we have a genuine ACK result
}
ackPulseStart=0; // We have detected a too-short or too-long pulse so ignore and wait for next leading edge
}
#pragma GCC pop_options