diff --git a/DCC.cpp b/DCC.cpp
index aec1662..b4b6fc1 100644
--- a/DCC.cpp
+++ b/DCC.cpp
@@ -38,6 +38,7 @@
#include "TrackManager.h"
#include "DCCTimer.h"
#include "Railcom.h"
+#include "DCCQueue.h"
// This module is responsible for converting API calls into
// messages to be sent to the waveform generator.
@@ -157,8 +158,8 @@ void DCC::setThrottle2( uint16_t cab, byte speedCode) {
b[nB++] = speedCode; // for encoding see setThrottle
}
-
- DCCWaveform::mainTrack.schedulePacket(b, nB, 0);
+ if ((speedCode & 0x7F) == 1) DCCQueue::scheduleEstopPacket(b, nB, 4, cab); // highest priority
+ else DCCQueue::scheduleDCCSpeedPacket( b, nB, 4, cab);
}
void DCC::setFunctionInternal(int cab, byte byte1, byte byte2, byte count) {
@@ -172,7 +173,7 @@ void DCC::setFunctionInternal(int cab, byte byte1, byte byte2, byte count) {
if (byte1!=0) b[nB++] = byte1;
b[nB++] = byte2;
- DCCWaveform::mainTrack.schedulePacket(b, nB, count);
+ DCCQueue::scheduleDCCPacket(b, nB, count);
}
// returns speed steps 0 to 127 (1 == emergency stop)
@@ -238,7 +239,7 @@ bool DCC::setFn( int cab, int16_t functionNumber, bool on) {
b[nB++] = (functionNumber & 0x7F) | (on ? 0x80 : 0); // low order bits and state flag
b[nB++] = functionNumber >>7 ; // high order bits
}
- DCCWaveform::mainTrack.schedulePacket(b, nB, 4);
+ DCCQueue::scheduleDCCPacket(b, nB, 4);
}
// We use the reminder table up to 28 for normal functions.
// We use 29 to 31 for DC frequency as well so up to 28
@@ -339,16 +340,17 @@ void DCC::setAccessory(int address, byte port, bool gate, byte onoff /*= 2*/) {
// second byte is of the form 1AAACPPG, where C is 1 for on, PP the ports 0 to 3 and G the gate (coil).
b[0] = address % 64 + 128;
b[1] = ((((address / 64) % 8) << 4) + (port % 4 << 1) + gate % 2) ^ 0xF8;
- if (onoff != 0) {
- DCCWaveform::mainTrack.schedulePacket(b, 2, 3); // Repeat on packet three times
-#if defined(EXRAIL_ACTIVE)
- RMFT2::activateEvent(address<<2|port,gate);
-#endif
- }
- if (onoff != 1) {
+ if (onoff==0) { // off packet only
b[1] &= ~0x08; // set C to 0
- DCCWaveform::mainTrack.schedulePacket(b, 2, 3); // Repeat off packet three times
- }
+ DCCQueue::scheduleDCCPacket(b, 2, 3);
+ } else if (onoff==1) { // on packet only
+ DCCQueue::scheduleDCCPacket(b, 2, 3);
+ } else { // auto timed on then off
+ DCCQueue::scheduleAccOnOffPacket(b, 2, 3, 100); // On then off after 100mS
+ }
+#if defined(EXRAIL_ACTIVE)
+ if (onoff !=0) RMFT2::activateEvent(address<<2|port,gate);
+#endif
}
bool DCC::setExtendedAccessory(int16_t address, int16_t value, byte repeats) {
@@ -398,7 +400,7 @@ whole range of the 11 bits sent to track.
| (((~(address>>8)) & 0x07)<<4) // shift out 8, invert, mask 3 bits, shift up 4
| ((address & 0x03)<<1); // mask 2 bits, shift up 1
b[2]=value;
- DCCWaveform::mainTrack.schedulePacket(b, sizeof(b), repeats);
+ DCCQueue::scheduleDCCPacket(b, sizeof(b), repeats);
return true;
}
@@ -417,7 +419,7 @@ void DCC::writeCVByteMain(int cab, int cv, byte bValue) {
b[nB++] = cv2(cv);
b[nB++] = bValue;
- DCCWaveform::mainTrack.schedulePacket(b, nB, 4);
+ DCCQueue::scheduleDCCPacket(b, nB, 4);
}
//
@@ -435,7 +437,7 @@ void DCC::readCVByteMain(int cab, int cv, ACK_CALLBACK callback) {
b[nB++] = cv2(cv);
b[nB++] = 0;
- DCCWaveform::mainTrack.schedulePacket(b, nB, 4);
+ DCCQueue::scheduleDCCPacket(b, nB, 4);
Railcom::anticipate(cab,cv,callback);
}
@@ -457,7 +459,7 @@ void DCC::writeCVBitMain(int cab, int cv, byte bNum, bool bValue) {
b[nB++] = cv2(cv);
b[nB++] = WRITE_BIT | (bValue ? BIT_ON : BIT_OFF) | bNum;
- DCCWaveform::mainTrack.schedulePacket(b, nB, 4);
+ DCCQueue::scheduleDCCPacket(b, nB, 4);
}
bool DCC::setTime(uint16_t minutes,uint8_t speed, bool suddenChange) {
@@ -494,7 +496,7 @@ b[1]=0b11000001; // 1100-0001 (model time)
b[2]=minutes % 60 ; // MM
b[3]= 0b11100000 | (minutes/60); // 111H-HHHH weekday not supported
b[4]= (suddenChange ? 0b10000000 : 0) | speed;
-DCCWaveform::mainTrack.schedulePacket(b, sizeof(b), 2);
+DCCQueue::scheduleDCCPacket(b, sizeof(b), 2);
return true;
}
@@ -844,12 +846,17 @@ byte DCC::loopStatus=0;
void DCC::loop() {
TrackManager::loop(); // power overload checks
- issueReminders();
+ if (DCCWaveform::mainTrack.isReminderWindowOpen()) {
+ // Now is a good time to choose a packet to be sent
+ // Either highest priority from the queues or a reminder
+ if (!DCCQueue::scheduleNext()) {
+ issueReminders();
+ DCCQueue::scheduleNext(); // push through any just created reminder
+ }
+ }
}
void DCC::issueReminders() {
- // if the main track transmitter still has a pending packet, skip this time around.
- if (!DCCWaveform::mainTrack.isReminderWindowOpen()) return;
// Move to next loco slot. If occupied, send a reminder.
auto slot = nextLocoReminder;
if (slot >= &speedTable[MAX_LOCOS]) slot=&speedTable[0]; // Go to start of table
diff --git a/DCCQueue.cpp b/DCCQueue.cpp
new file mode 100644
index 0000000..8330e74
--- /dev/null
+++ b/DCCQueue.cpp
@@ -0,0 +1,185 @@
+/*
+ * © 2025 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 .
+ */
+
+
+#include "Arduino.h"
+#include "defines.h"
+#include "DCCQueue.h"
+#include "DCCWaveform.h"
+#include "DIAG.h"
+
+// create statics
+DCCQueue* DCCQueue::lowPriorityQueue=new DCCQueue();
+DCCQueue* DCCQueue::highPriorityQueue=new DCCQueue();
+PendingSlot* DCCQueue::recycleList=nullptr;
+
+ DCCQueue::DCCQueue() {
+ head=nullptr;
+ tail=nullptr;
+ }
+
+ void DCCQueue::addQueue(PendingSlot* p) {
+ if (tail) tail->next=p;
+ else head=p;
+ tail=p;
+ p->next=nullptr;
+ }
+
+ void DCCQueue::jumpQueue(PendingSlot* p) {
+ p->next=head;
+ head=p;
+ if (!tail) tail=p;
+ }
+
+
+ void DCCQueue::recycle(PendingSlot* p) {
+ p->next=recycleList;
+ recycleList=p;
+ }
+
+ // Packet joins end of low priority queue.
+ void DCCQueue::scheduleDCCPacket(byte* packet, byte length, byte repeats) {
+ lowPriorityQueue->addQueue(getSlot(NORMAL_PACKET,packet,length,repeats,0));
+ }
+
+ // Packet replaces existing loco speed packet or joins end of high priority queue.
+
+ void DCCQueue::scheduleDCCSpeedPacket(byte* packet, byte length, byte repeats, uint16_t loco) {
+ for (auto p=highPriorityQueue->head;p;p=p->next) {
+ if (p->locoId==loco) {
+ // replace existing packet
+ memcpy(p->packet,packet,length);
+ p->packetLength=length;
+ p->packetRepeat=repeats;
+ return;
+ }
+ }
+ highPriorityQueue->addQueue(getSlot(NORMAL_PACKET,packet,length,repeats,loco));
+ }
+
+
+ // ESTOP -
+ // any outstanding throttle packet for this loco (all if loco=0) discarded
+ // Packet joins start of queue,
+
+
+ void DCCQueue::scheduleEstopPacket(byte* packet, byte length, byte repeats,uint16_t loco) {
+
+ // DIAG(F("DCC ESTOP loco=%d"),loco);
+
+ // kill any existing throttle packets for this loco
+ PendingSlot * previous=nullptr;
+ auto p=highPriorityQueue->head;
+ while(p) {
+ if (loco==0 || p->locoId==loco) {
+ // drop this packet from the highPriority queue
+ if (previous) previous->next=p->next;
+ else highPriorityQueue->head=p->next;
+
+ recycle(p); // recycle this slot
+
+ // address next packet
+ p=previous?previous->next : highPriorityQueue->head;
+ }
+ else {
+ previous=p;
+ p=p->next;
+ }
+ }
+ // add the estop packet to the start of the queue
+ highPriorityQueue->jumpQueue(getSlot(NORMAL_PACKET,packet,length,repeats,0));
+ }
+
+ // Accessory gate-On Packet joins end of queue as normal.
+ // When dequeued, packet is retained at start of queue
+ // but modified to gate-off and given the delayed start.
+ // getNext will ignore this packet until the requested start time.
+ void DCCQueue::scheduleAccOnOffPacket(byte* packet, byte length, byte repeats,int16_t delayms) {
+ auto p=getSlot(ACC_ON_PACKET,packet,length,repeats,0);
+ p->delayOff=delayms;
+ lowPriorityQueue->addQueue(p);
+ };
+
+
+ // Obtain packet (fills packet, length and repeats)
+ // returns 0 length if nothing in queue.
+
+ bool DCCQueue::scheduleNext() {
+ // check high priority queue first
+ if (!DCCWaveform::mainTrack.isReminderWindowOpen()) return false;
+ PendingSlot* previous=nullptr;
+ for (auto p=highPriorityQueue->head;p;p=p->next) {
+ // skip over pending ACC_OFF packets which are still delayed
+ if (p->type == ACC_OFF_PACKET && millis()startTime) continue;
+ // use this slot
+ DCCWaveform::mainTrack.schedulePacket(p->packet,p->packetLength,p->packetRepeat);
+ // remove this slot from the queue
+ if (previous) previous->next=p->next;
+ else highPriorityQueue->head=p->next;
+ if (!highPriorityQueue->head) highPriorityQueue->tail=nullptr;
+
+ // and recycle it.
+ recycle(p);
+ return true;
+ }
+
+ // No high priopity packets found, check low priority queue
+ auto p=lowPriorityQueue->head;
+ if (!p) return false; // nothing in queues
+
+ // schedule first packet in queue
+ DCCWaveform::mainTrack.schedulePacket(p->packet,p->packetLength,p->packetRepeat);
+
+ // remove from queue
+ lowPriorityQueue->head=p->next;
+ if (!lowPriorityQueue->head) lowPriorityQueue->tail=nullptr;
+
+ if (p->type == ACC_ON_PACKET) {
+ // convert to a delayed off packet and jump the high priority queue
+ p->type= ACC_OFF_PACKET;
+ p->packet[1] &= ~0x08; // set C to 0 (gate off)
+ p->startTime=millis()+p->delayOff;
+ highPriorityQueue->jumpQueue(p);
+ }
+ else recycle(p); // recycle this slot
+ return true;
+ }
+
+ // obtain and initialise slot for a PendingSlot.
+ PendingSlot* DCCQueue::getSlot(PendingType type, byte* packet, byte length, byte repeats,uint16_t loco) {
+ PendingSlot * p;
+ if (recycleList) {
+ p=recycleList;
+ recycleList=p->next;
+ }
+ else {
+ DIAG(F("New DCC queue slot"));
+ p=new PendingSlot; // need a queue entry
+ }
+ p->next=nullptr;
+ p->type=type;
+ p->packetLength=length;
+ p->packetRepeat=repeats;
+ memcpy((void*)p->packet,packet,length);
+ p->locoId=loco;
+ return p;
+ }
+
+
diff --git a/DCCQueue.h b/DCCQueue.h
new file mode 100644
index 0000000..4c1eacb
--- /dev/null
+++ b/DCCQueue.h
@@ -0,0 +1,84 @@
+/*
+ * © 2025 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 .
+ */
+
+#ifndef DCCQueue_h
+#define DCCQueue_h
+#include "Arduino.h"
+#include "DCCWaveform.h"
+
+enum PendingType:byte {NORMAL_PACKET,ACC_ON_PACKET,ACC_OFF_PACKET,DEAD_PACKET};
+ struct PendingSlot {
+ PendingSlot* next;
+ PendingType type;
+ byte packetLength;
+ byte packetRepeat;
+ byte packet[MAX_PACKET_SIZE];
+
+ union { // use depends on packet type
+ uint16_t locoId; // NORMAL_PACKET .. only set >0 for speed change packets
+ // so they can be easily discarded if an estop jumps the queue.
+ uint16_t delayOff; // ACC_ON_PACKET delay to apply between on/off
+ uint32_t startTime; // ACC_OFF_PACKET time (mS) to transmit
+ };
+ };
+
+class DCCQueue {
+ public:
+
+
+ // Non-speed packets are queued in the main queue
+ static void scheduleDCCPacket(byte* packet, byte length, byte repeats);
+
+ // Speed packets are queued in the high priority queue
+ static void scheduleDCCSpeedPacket(byte* packet, byte length, byte repeats, uint16_t loco);
+
+ // ESTOP packets jump the high priority queue and discard any outstanding throttle packets for this loco
+ static void scheduleEstopPacket(byte* packet, byte length, byte repeats,uint16_t loco);
+
+ // Accessory gate-On Packet joins end of main queue as normal.
+ // When dequeued, packet is modified to gate-off and given the delayed start in the high priority queue.
+ // getNext will ignore this packet until the requested start time.
+ static void scheduleAccOnOffPacket(byte* packet, byte length, byte repeats,int16_t delayms);
+
+
+ // Schedules a main track packet from the queues if none pending.
+ // returns true if a packet was scheduled.
+ static bool scheduleNext();
+
+ private:
+
+ // statics to manage high and low priority queues and recycleing of PENDINGs
+ static PendingSlot* recycleList;
+ static DCCQueue* highPriorityQueue;
+ static DCCQueue* lowPriorityQueue;
+
+ DCCQueue();
+
+ PendingSlot* head;
+ PendingSlot * tail;
+
+ // obtain and initialise slot for a PendingSlot.
+ static PendingSlot* getSlot(PendingType type, byte* packet, byte length, byte repeats, uint16_t loco);
+ static void recycle(PendingSlot* p);
+ void addQueue(PendingSlot * p);
+ void jumpQueue(PendingSlot * p);
+
+};
+#endif
\ No newline at end of file
diff --git a/version.h b/version.h
index 372491e..6334f14 100644
--- a/version.h
+++ b/version.h
@@ -3,7 +3,8 @@
#include "StringFormatter.h"
-#define VERSION "5.5.13"
+#define VERSION "5.5.14"
+// 5.5.14 - DCC Non-blocking packet queue with priority
// 5.5.13 - Update STM32duino core to v19.0.0. for updated PeripheralPins.c in preparation for F429/439ZI Ethernet support
// 5.5.12 - Websocket support (wifi only)
// 5.5.11 - (5.4.2) accessory command reverse