From 6d2a9e3b36e08264dfb3ffc0acf575b2ecad7c56 Mon Sep 17 00:00:00 2001
From: Harald Barth <haba@kth.se>
Date: Wed, 18 May 2022 09:40:53 +0200
Subject: [PATCH] add EXT as a new track mode

---
 MotorDriver.h    |  6 ++++++
 TrackManager.cpp | 26 ++++++++++++++++++++++----
 TrackManager.h   |  2 +-
 3 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/MotorDriver.h b/MotorDriver.h
index 6c39058..a7fe96c 100644
--- a/MotorDriver.h
+++ b/MotorDriver.h
@@ -99,6 +99,12 @@ class MotorDriver {
 	}
       }
     };
+    inline void enableSignal(bool on) {
+      if (on)
+	pinMode(signalPin, OUTPUT);
+      else
+	pinMode(signalPin, INPUT);
+    };
     virtual void setBrake( bool on);
     virtual void setDCSignal(byte speedByte);
     virtual int  getCurrentRaw();
diff --git a/TrackManager.cpp b/TrackManager.cpp
index ccbed6f..87d64ce 100644
--- a/TrackManager.cpp
+++ b/TrackManager.cpp
@@ -37,6 +37,7 @@ const int16_t HASH_KEYWORD_MAIN = 11339;
 const int16_t HASH_KEYWORD_OFF = 22479;  
 const int16_t HASH_KEYWORD_DC = 2183;  
 const int16_t HASH_KEYWORD_DCX = 6463; // DC reversed polarity 
+const int16_t HASH_KEYWORD_EXT = 8201; // External DCC signal
 const int16_t HASH_KEYWORD_A = 65; // parser makes single chars the ascii.   
 
 MotorDriver * TrackManager::track[MAX_TRACKS];
@@ -161,9 +162,14 @@ bool TrackManager::setTrackMode(byte trackToSet, TRACK_MODE mode, int16_t dcAddr
     }
     else {
         // DCC tracks need to have the brake set off or they will not work.
-        track[trackToSet]->setBrake(false); 
+        track[trackToSet]->setBrake(false);
     }
-    
+
+    // EXT is a special case where the signal pin is
+    // turned off. So unless that is set, the signal
+    // pin should be turned on
+    track[trackToSet]->enableSignal(mode != TRACK_MODE_EXT);
+
     // re-evaluate HighAccuracy mode
     // We can only do this is all main and prog tracks agree
     bool canDo=true;
@@ -225,6 +231,9 @@ bool TrackManager::parseJ(Print *stream, int16_t params, int16_t p[])
                     case TRACK_MODE_OFF:
                         StringFormatter::send(stream,F("OFF"));
                         break;
+                    case TRACK_MODE_EXT:
+                        StringFormatter::send(stream,F("EXT"));
+                        break;
                     case TRACK_MODE_DC:
                         StringFormatter::send(stream,F("DC %d"),trackDCAddr[t]);
                         break;
@@ -252,7 +261,10 @@ bool TrackManager::parseJ(Print *stream, int16_t params, int16_t p[])
     
     if (params==2  && p[1]==HASH_KEYWORD_OFF) // <= id OFF>
         return setTrackMode(p[0],TRACK_MODE_OFF);
-    
+
+    if (params==2  && p[1]==HASH_KEYWORD_EXT) // <= id EXT>
+        return setTrackMode(p[0],TRACK_MODE_EXT);
+
     if (params==3  && p[1]==HASH_KEYWORD_DC && p[2]>0) // <= id DC cab>
         return setTrackMode(p[0],TRACK_MODE_DC,p[2]);
     
@@ -291,7 +303,8 @@ void TrackManager::setPower2(bool setProg,POWERMODE mode) {
             case TRACK_MODE_MAIN:
                 if (setProg) break; 
                 // toggle brake before turning power on - resets overcurrent error
-                // on the Pololu board if brake is wired to ^D2.   
+                // on the Pololu board if brake is wired to ^D2.
+		// XXX see if we can make this conditional
                 driver->setBrake(true);
                 driver->setBrake(false); // DCC runs with brake off
                 driver->setPower(mode);  
@@ -309,6 +322,11 @@ void TrackManager::setPower2(bool setProg,POWERMODE mode) {
                 driver->setBrake(false);
                 driver->setPower(mode);
                 break;  
+            case TRACK_MODE_EXT:
+	        driver->setBrake(true);
+	        driver->setBrake(false);
+		driver->setPower(mode);
+	        break;
             case TRACK_MODE_OFF:
                 break;
         }
diff --git a/TrackManager.h b/TrackManager.h
index fcbda17..8185e97 100644
--- a/TrackManager.h
+++ b/TrackManager.h
@@ -24,7 +24,7 @@
 // Virtualised Motor shield multi-track hardware Interface
 
 enum TRACK_MODE : byte {TRACK_MODE_OFF, TRACK_MODE_MAIN, TRACK_MODE_PROG,
-                        TRACK_MODE_DC, TRACK_MODE_DCX};
+                        TRACK_MODE_DC, TRACK_MODE_DCX, TRACK_MODE_EXT};
 
 // These constants help EXRAIL macros say SET_TRACK(2,mode) OR SET_TRACK(C,mode) etc.
 const byte TRACK_NUMBER_0=0, TRACK_NUMBER_A=0;