delay long only at write, poweroff short always at rejoi

DCC.cpp

@@ -772,7 +772,7 @@ void DCC::ackManagerLoop() {
           if (DCCWaveform::progTrack.getPowerMode()==POWERMODE::OVERLOAD) return;
       	  if (checkResets(DCCWaveform::progTrack.autoPowerOff || ackManagerRejoin  ? 20 : 3)) return;
           DCCWaveform::progTrack.setAckBaseline();
-          callbackState=READY;
+          callbackState=AFTER_READ;
           break;
       case W0:    // write 0 bit
       case W1:    // write 1 bit
@@ -958,6 +958,7 @@ void DCC::callback(int value) {
 
     switch (callbackState) {
        case AFTER_WRITE:  // first attempt to callback after a write operation
+	    // If no poweroff and no rejoin planned, continue without delay.	    
 	    if (!ackManagerRejoin && !DCCWaveform::progTrack.autoPowerOff) {
                callbackState=READY;
                break;
@@ -966,20 +967,24 @@ void DCC::callback(int value) {
             callbackState=WAITING_100;
             if (Diag::ACK) DIAG(F("Stable 100mS"));
             break;
-
-       case WAITING_100:  // waiting for 100mS
+       case AFTER_READ:
+         // If we are going to power off anyway, it doesnt matter
+         // but if we will keep the power on, we must off it for 30mS
+         // If we do not plan do rejoin, we don't need to power off either
+         if (DCCWaveform::progTrack.autoPowerOff || !ackManagerRejoin) {
+	   callbackState=READY;
+	 } else {
+	   DCCWaveform::progTrack.setPowerMode(POWERMODE::OFF);
+	   callbackStart=millis();
+	   callbackState=WAITING_30;
+	   if (Diag::ACK) DIAG(F("OFF 30mS"));
+	 }
+	 break;
+       case WAITING_100:  // waiting for 100mS for decoder write to settle
             if (millis()-callbackStart < 100) break;
             // stable after power maintained for 100mS
-
-            // If we are going to power off anyway, it doesnt matter
-            // but if we will keep the power on, we must off it for 30mS
-            if (DCCWaveform::progTrack.autoPowerOff) callbackState=READY;
-            else { // Need to cycle power off and on
-                DCCWaveform::progTrack.setPowerMode(POWERMODE::OFF);
-                callbackStart=millis();
-                callbackState=WAITING_30;
-                if (Diag::ACK) DIAG(F("OFF 30mS"));
-            }
+	    // still may need to do the 30mS delay
+            callbackState=AFTER_READ;
             break;
 
         case WAITING_30:  // waiting for 30mS with power off

DCC.h

@@ -73,6 +73,7 @@ enum ackOp : byte
 
 enum   CALLBACK_STATE : byte {
   AFTER_WRITE,  // Start callback sequence after something was written to the decoder  
+  AFTER_READ,   // Start callback sequence after something was read from the decoder
   WAITING_100,        // Waiting for 100mS of stable power 
   WAITING_30,         // waiting to 30ms of power off gap. 
   READY,              // Ready to complete callback  

Release_Notes/release_notes_v4.0.0.md

@@ -60,6 +60,7 @@ The DCC-EX Team is pleased to release CommandStation-EX-v4.0.0 as a Production R
 - Additional Motor Shields and Motor Board {boosters) supported
 - Additional Accessory boards supported for GPIO expansion, Sensors, Servos & Signals
 - Additional diagnostic commands like ‘D ACK RETRY’ and ‘D EXRAIL ON’ events, ‘D HAL SHOW’ devices and ‘D SERVO’ positions, and ‘D RESET’ the command station while maintaining the serial connection with JMRI
+- Automatic retry on failed ACK detection to give decoders another chance
 - New EX-RAIL ’/’ slash command allows JMRI to directly communicate with many EX-RAIL scripts
 - Turnout class revised to expand turnout capabilities and allow turnout names/descriptors to display in WiThrottle Apps.
 - Build turnouts through either or both mySetup.h and myAutomation.h files, and have them automatically passed to, and populate, JMRI Turnout Tables

release_notes.md

@@ -58,6 +58,7 @@ The DCC-EX Team is pleased to release CommandStation-EX-v4.0.0 as a Production R
 - Additional Motor Shields and Motor Board {boosters) supported
 - Additional Accessory boards supported for GPIO expansion, Sensors, Servos & Signals
 - Additional diagnostic commands like ‘D ACK RETRY’ and ‘D EXRAIL ON’ events, ‘D HAL SHOW’ devices and ‘D SERVO’ positions, and ‘D RESET’ the command station while maintaining the serial connection with JMRI
+- Automatic retry on failed ACK detection to give decoders another chance
 - New EX-RAIL ’/’ slash command allows JMRI to directly communicate with many EX-RAIL scripts
 - Turnout class revised to expand turnout capabilities and allow turnout names/descriptors to display in WiThrottle Apps.
 - Build turnouts through either or both mySetup.h and myAutomation.h files, and have them automatically passed to, and populate, JMRI Turnout Tables