Move ring buffer implemented and (preliminarily) tested. Look ahead not yet done.

Move.h

@@ -55,53 +55,19 @@ class DDA
 
 //*********************************************************************************************
 
-/*
-
-  To call the RingBuffer functions the sequences are:
-  
-  Get:
-  
-    if(ringBuffer->getLock())
-    {
-      if(ringBuffer->Empty())
-      {
-        ringBuffer->releaseLock();
-        // Nothing there - go and do something else...
-      }
-      d = Get();
-      ringBuffer->releaseLock();
-      // Do something with d and don't do another Get until you have finished with d...
-    }
-  
-  Add:
-  
-    if(ringBuffer->getLock())
-    {
-      if(ringBuffer->Full())
-      {
-        ringBuffer->releaseLock();
-        // No room - come back later...
-      }
-      ringBuffer->Add(...);
-      ringBuffer->releaseLock();
-    }
-  
-  
-
-*/
-
 class DDARingBuffer
 {
   public:
    DDARingBuffer(Move* m, Platform* p);
-   void Add(float currentPosition[], float targetPosition[], float& u, float& v);
+   boolean Add(float currentPosition[], float targetPosition[], float& u, float& v);
    DDA* Get();
+
+  private:
    boolean Empty();
    boolean Full();
    boolean getLock();
    void releaseLock();
    
-  private:
    Platform* platform;
    DDA* ring[RING_LENGTH];
    volatile char addPointer;
@@ -130,8 +96,10 @@ class Move
     Platform* platform;
     GCodes* gCodes;
     DDA* dda;
+    DDARingBuffer* ddaRingBuffer;
     unsigned long lastTime;
     boolean active;
+    boolean moveWaiting;
     float currentFeedrate;
     float currentPosition[AXES]; // Note - drives above AXES are always relative moves
     float nextMove[DRIVES + 1];  // Extra is for feedrate
@@ -164,37 +132,60 @@ inline boolean DDARingBuffer::getLock()
 inline void DDARingBuffer::releaseLock()
 {
   if(!locked)
-    platform->Message(HOST_MESSAGE, "Attempt to unlock already unlocked ring buffer.\n");
+    platform->Message(HOST_MESSAGE, "Attempt to unlock an already unlocked ring buffer!\n");
   locked = false;
   return;
 }
 
-inline void DDARingBuffer::Add(float currentPosition[], float targetPosition[], float& u, float& v)
+inline boolean DDARingBuffer::Add(float currentPosition[], float targetPosition[], float& u, float& v)
 {
-  if(Full())
+  if(getLock())
   {
-    platform->Message(HOST_MESSAGE, "Attempt to overfill ring buffer.\n");
+    if(Full())
-    return;
+    {
+      releaseLock();
+      return false;
+    }
+    if(ring[addPointer]->Active())
+    {
+      platform->Message(HOST_MESSAGE, "Attempt to alter an active ring buffer entry!\n");
+      releaseLock();
+      return false;
+    }
+    if(!ring[addPointer]->Init(currentPosition, targetPosition, u, v))
+    {
+      // Throw it away
+      releaseLock();
+      return true;
+    }
+    addPointer++;
+    if(addPointer >= RING_LENGTH)
+      addPointer = 0;
+    releaseLock();
+    return true;
   }
-
+  return false;
-  ring[addPointer]->Init(currentPosition, targetPosition, u, v);
-  addPointer++;
-  if(addPointer >= RING_LENGTH)
-    addPointer = 0;
 }
 
+
 inline DDA* DDARingBuffer::Get()
 {
-  if(Empty())
+  DDA* result = NULL;
+  if(getLock())
   {
-    platform->Message(HOST_MESSAGE, "Attempt to use empty ring buffer.\n");
+    if(Empty())
-    return ring[getPointer]; // Safer than NULL
+    {
+      releaseLock();
+      return NULL;
+    }
+    result = ring[getPointer];
+    getPointer++;
+    if(getPointer >= RING_LENGTH)
+      getPointer = 0;
+    releaseLock();
+    return result;
   }
-  DDA* d = ring[getPointer];
+  return NULL;
-  getPointer++;
-  if(getPointer >= RING_LENGTH)
-    getPointer = 0;
-  return d;
 }
 
 inline boolean DDARingBuffer::Empty()
@@ -217,7 +208,21 @@ inline boolean DDARingBuffer::Full()
 
 inline void Move::Interrupt()
 {
-  dda->Step(true);
+  if(dda == NULL)
+  {
+    dda = ddaRingBuffer->Get();
+    if(dda != NULL)
+      dda->Start(true);
+    return;   
+  }
+  
+  if(dda->Active())
+  {
+    dda->Step(true);
+    return;
+  }
+  
+  dda = NULL;
 }
 
 

Move.ino

@@ -25,7 +25,8 @@ Move::Move(Platform* p, GCodes* g)
   active = false;
   platform = p;
   gCodes = g;
-  dda = new DDA(this, platform);
+  dda = NULL;
+  ddaRingBuffer = new DDARingBuffer(this, platform);
 }
 
 void Move::Init()
@@ -80,6 +81,7 @@ void Move::Init()
   
   lastTime = platform->Time();
   currentFeedrate = START_FEED_RATE;
+  moveWaiting = false;
   active = true;  
 }
 
@@ -98,20 +100,23 @@ void Move::Spin()
 
 void Move::Qmove()
 {
-  if(!gCodes->ReadMove(nextMove))
-    return;
-    
   //FIXME
   float u = 0.0; // This will provoke the code to select the jerk values.
   float v = 0.0;
   
-  boolean work = dda->Init(currentPosition, nextMove, u, v);
+  if(moveWaiting)
+  {
+    if(ddaRingBuffer->Add(currentPosition, nextMove, u, v))
+    {
+      for(char i = 0; i < AXES; i++)
+        currentPosition[i] = nextMove[i];
+      currentFeedrate = nextMove[DRIVES];
+      moveWaiting = false;
+    }
+    return;
+  }
     
-  for(char i = 0; i < AXES; i++)
+  moveWaiting = gCodes->ReadMove(nextMove);
-    currentPosition[i] = nextMove[i];
-    
-  if(work)
-    dda->Start(true);
 }
 
 void Move::GetCurrentState(float m[])
@@ -411,8 +416,8 @@ void DDA::Step(boolean noTest)
   stepCount++;
   active = stepCount < totalSteps;
   
-  if(!active && noTest)           //???
+  if(!active && noTest)
-    platform->SetInterrupt(-1);
+    platform->SetInterrupt(STANDBY_INTERRUPT_RATE);
 }
 
 //****************************************************************************************************

Platform.h

@@ -152,15 +152,10 @@ Licence: GPL
 
 #define BAUD_RATE 115200 // Communication speed of the USB if needed.
 
-
+#define STANDBY_INTERRUPT_RATE 200 // Microseconds
-
 
 /****************************************************************************************************/
 
-//class RepRap;
-
-void TC3_Handler();
-
 class Platform
 {   
   public:
@@ -388,7 +383,7 @@ void Platform::InitialiseInterrupts()
   TC_Configure(TC1, 0, TC_CMR_WAVE | TC_CMR_WAVSEL_UP_RC | TC_CMR_TCCLKS_TIMER_CLOCK4);
   TC1->TC_CHANNEL[0].TC_IER=TC_IER_CPCS;
   TC1->TC_CHANNEL[0].TC_IDR=~TC_IER_CPCS;
-  NVIC_DisableIRQ(TC3_IRQn);  
+  SetInterrupt(STANDBY_INTERRUPT_RATE); 
 }
 
 inline void Platform::SetInterrupt(long t)