diff --git a/CVReader.ino b/CVReader.ino
index 9ba6724..9b2edd8 100644
--- a/CVReader.ino
+++ b/CVReader.ino
@@ -22,10 +22,10 @@ void myFilter(Print & stream, byte & opcode, byte & paramCount, int p[]) {
              DCC::setFn(p[0],p[1],p[2]==1); 
              opcode=0;  // tell parser to ignore this command
              break; 
-       case '#':   // Diagnose parser <#....>
-            DIAG(F("# paramCount=%d\n"),paramCount);
+       case '$':   // Diagnose parser <$....>
+            DIAG(F("$ paramCount=%d\n"),paramCount);
             for (int i=0;i<paramCount;i++) DIAG(F("p[%d]=%d (0x%x)\n"),i,p[i],p[i]);
-            opcode=0; // Normal parser wont understand #, 
+            opcode=0; // Normal parser wont understand $, 
             break;
        default:  // drop through and parser will use the command unaltered.   
             break;  
@@ -50,7 +50,8 @@ DCCEXParser  serialParser;
 
 // Try monitoring the memory
 #include "freeMemory.h"
-int minMemory=32767;
+//int minMemory=32767;
+int minMemory=2048;
 
 void setup() {
 
@@ -68,8 +69,10 @@ void setup() {
    //         and a 9600 baud rate. 
    //  setup(serial, F(router name), F(password) , port)
    //            
+#ifdef WIFI
     Serial1.begin(115200);
     WifiInterface::setup(Serial1, F("BTHub5-M6PT"), F("49de8d4862"),3532); // (3532 is 0xDCC decimal... )
+#endif
     
    //  This is just for demonstration purposes 
    DIAG(F("\n===== CVReader demonstrating DCC::getLocoId() call ==========\n"));
@@ -95,7 +98,9 @@ void loop() {
   serialParser.loop(Serial);
 
   // Responsibility 3: Optionally handle any incoming WiFi traffic
+#ifdef WIFI
   WifiInterface::loop(Serial1);
+#endif
 
   // Your additional code e.g. Report any decrease in memory
   int freeNow=freeMemory();
diff --git a/Config.h b/Config.h
index e3e22d5..d690ad7 100644
--- a/Config.h
+++ b/Config.h
@@ -8,6 +8,7 @@ const byte MAIN_SIGNAL_PIN = 12;
 const byte MAIN_SIGNAL_PIN_ALT = 0;  // for hardware that flipflops signal pins 
 const byte MAIN_SENSE_PIN = A0;   
 const byte MAIN_BRAKE_PIN = 9;
+const float MAIN_SENSE_FACTOR=1.717; //  analgRead(MAIN_SENSE_PIN) * MAIN_SENSE_FACTOR = milliamps 
 
 const int   MAIN_MAX_MILLIAMPS=2000;
 const float MAIN_SENSE_FACTOR=2.99; //  analgRead(MAIN_SENSE_PIN) * MAIN_SENSE_FACTOR = milliamps 
@@ -19,7 +20,7 @@ const byte PROG_SENSE_PIN = A1;
 const byte PROG_BRAKE_PIN = 8;
 
 const int   PROG_MAX_MILLIAMPS=250;
-const float PROG_SENSE_FACTOR=2.99; //  analgRead(PROG_SENSE_PIN) * PROG_SENSE_FACTOR = milliamps 
+const float PROG_SENSE_FACTOR=1.717; //  analgRead(PROG_SENSE_PIN) * PROG_SENSE_FACTOR = milliamps 
 
 // Allocations with memory implications..!
 // Base system takes approx 900 bytes + 8 per loco. Turnouts, Sensors etc are dynamically created
diff --git a/DCCEXParser.cpp b/DCCEXParser.cpp
index b8bc54e..f96cec8 100644
--- a/DCCEXParser.cpp
+++ b/DCCEXParser.cpp
@@ -232,6 +232,10 @@ void DCCEXParser::parse(Print & stream, const byte *com, bool banAsync) {
         DCC::setDebug(p[0]==1);
         DIAG(F("\nDCC DEBUG MODE %d"),p[0]==1);
         return;
+
+    case '#':     // NUMBER OF LOCOSLOTS <#>
+	StringFormatter::send(stream,F("<# %d>"), MAX_LOCOS);
+	return;
         
      default:  //anything else will drop out to <X>
         break;
diff --git a/DCCWaveform.cpp b/DCCWaveform.cpp
index bdeacc4..6081132 100644
--- a/DCCWaveform.cpp
+++ b/DCCWaveform.cpp
@@ -140,8 +140,9 @@ bool DCCWaveform::interrupt1() {
       state = 0;
       break;
   }
+  // ACK check is prog track only
+  if (ackPending) checkAck();
   return false;
-
 }
 
 
@@ -190,11 +191,6 @@ void DCCWaveform::interrupt2() {
       }
     }
   }
-  
-  // ACK check is prog track only and will only be checked if bits_sent=4 ...
-  // This means only once per 9-bit-byte AND never at the same cycle as the 
-  // relatively expensive packet change code just above.
-  if (ackPending && bits_sent==4) checkAck();
 }
 
 
@@ -271,13 +267,13 @@ void DCCWaveform::checkAck() {
     
     // detected trailing edge of pulse
     ackPulseDuration=micros()-ackPulseStart;
-               
-    if (ackPulseDuration>1000 && ackPulseDuration<9000) {
+
+    if (ackPulseDuration>3000 && ackPulseDuration<8500) {
         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 
 }
diff --git a/Hardware.cpp b/Hardware.cpp
index 532240e..7643f32 100644
--- a/Hardware.cpp
+++ b/Hardware.cpp
@@ -47,10 +47,6 @@ int Hardware::getCurrentRaw(bool isMainTrack) {
  
 }
 
-unsigned int Hardware::getCurrentMilliamps(bool isMainTrack, int raw) {
-  return (int)(raw * (isMainTrack ? MAIN_SENSE_FACTOR : PROG_SENSE_FACTOR));
-}
-
 void Hardware::setCallback(int duration, void (*isr)()) {
   Timer1.initialize(duration);
   // We don't want the timer to set pins because these often clash with motor shields etc.