1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
|
/*
* DDA.h
*
* Created on: 7 Dec 2014
* Author: David
*/
#ifndef DDA_H_
#define DDA_H_
#include "RepRapFirmware.h"
#include "DriveMovement.h"
#include "GCodes/GCodes.h" // for class RawMove
#ifdef DUET_NG
#define DDA_LOG_PROBE_CHANGES 1
#else
#define DDA_LOG_PROBE_CHANGES 0 // save memory on the wired Duet
#endif
/**
* This defines a single linear movement of the print head
*/
class DDA
{
friend class DriveMovement;
public:
enum DDAState : unsigned char
{
empty, // empty or being filled in
provisional, // ready, but could be subject to modifications
frozen, // ready, no further modifications allowed
executing, // steps are currently being generated for this DDA
completed // move has been completed or aborted
};
DDA(DDA* n);
bool Init(const GCodes::RawMove &nextMove, bool doMotorMapping); // Set up a new move, returning true if it represents real movement
void Init(); // Set up initial positions for machine startup
bool Start(uint32_t tim); // Start executing the DDA, i.e. move the move.
bool Step(); // Take one step of the DDA, called by timed interrupt.
void SetNext(DDA *n) { next = n; }
void SetPrevious(DDA *p) { prev = p; }
void Complete() { state = completed; }
bool Free();
void Prepare(); // Calculate all the values and freeze this DDA
float CalcTime() const; // Calculate the time needed for this move (used for simulation)
bool HasStepError() const;
bool CanPauseAfter() const { return canPauseAfter; }
bool IsPrintingMove() const { return isPrintingMove; } // Return true if this involves both XY movement and extrusion
DDAState GetState() const { return state; }
DDA* GetNext() const { return next; }
DDA* GetPrevious() const { return prev; }
int32_t GetTimeLeft() const;
float GetMotorPosition(size_t drive) const; // Get the real mm position of a motor at the planned endpoint of this move
const int32_t *DriveCoordinates() const { return endPoint; } // Get endpoints of a move in machine coordinates
void SetDriveCoordinate(int32_t a, size_t drive); // Force an end point
void SetFeedRate(float rate) { requestedSpeed = rate; }
float GetEndCoordinate(size_t drive, bool disableDeltaMapping);
bool FetchEndPosition(volatile int32_t ep[DRIVES], volatile float endCoords[DRIVES]);
void SetPositions(const float move[], size_t numDrives); // Force the endpoints to be these
FilePosition GetFilePosition() const { return filePos; }
float GetRequestedSpeed() const { return requestedSpeed; }
void DebugPrint() const;
static const uint32_t stepClockRate = VARIANT_MCK/128; // the frequency of the clock used for stepper pulse timing (see Platform::InitialiseInterrupts)
static const uint64_t stepClockRateSquared = (uint64_t)stepClockRate * stepClockRate;
// Note on the following constant:
// If we calculate the step interval on every clock, we reach a point where the calculation time exceeds the step interval.
// The worst case is pure Z movement on a delta. On a Mini Kossel with 80 steps/mm with this firmware running on a Duet (84MHx SAM3X8 processor),
// the calculation can just be managed in time at speeds of 15000mm/min (step interval 50us), but not at 20000mm/min (step interval 37.5us).
// Therefore, where the step interval falls below 60us, we don't calculate on every step.
// Note: the above measurements were taken some time ago, before some firmware optimisations.
#ifdef DUET_NG
static const int32_t MinCalcIntervalDelta = (40 * stepClockRate)/1000000; // the smallest sensible interval between calculations (40us) in step timer clocks
static const int32_t MinCalcIntervalCartesian = (40 * stepClockRate)/1000000; // same as delta for now, but could be lower
static const uint32_t minInterruptInterval = 6; // about 2us minimum interval between interrupts, in clocks
#else
static const int32_t MinCalcIntervalDelta = (60 * stepClockRate)/1000000; // the smallest sensible interval between calculations (60us) in step timer clocks
static const int32_t MinCalcIntervalCartesian = (60 * stepClockRate)/1000000; // same as delta for now, but could be lower
static const uint32_t minInterruptInterval = 6; // about 2us minimum interval between interrupts, in clocks
#endif
static void PrintMoves(); // print saved moves for debugging
#if DDA_LOG_PROBE_CHANGES
static const size_t MaxLoggedProbePositions = 40;
static size_t numLoggedProbePositions;
static int32_t loggedProbePositions[MIN_AXES * MaxLoggedProbePositions];
#endif
private:
void RecalculateMove();
void CalcNewSpeeds();
void ReduceHomingSpeed(); // called to reduce homing speed when a near-endstop is triggered
void StopDrive(size_t drive); // stop movement of a drive and recalculate the endpoint
void MoveAborted();
void InsertDM(DriveMovement *dm);
DriveMovement *RemoveDM(size_t drive);
bool IsDecelerationMove() const; // return true if this move is or have been might have been intended to be a deceleration-only move
void DebugPrintVector(const char *name, const float *vec, size_t len) const;
void CheckEndstops(Platform *platform);
void AdvanceBabyStepping(float amount); // Try to push babystepping earlier in the move queue
static void DoLookahead(DDA *laDDA); // Try to smooth out moves in the queue
static float Normalise(float v[], size_t dim1, size_t dim2); // Normalise a vector of dim1 dimensions to unit length in the first dim1 dimensions
static void Absolute(float v[], size_t dimensions); // Put a vector in the positive hyperquadrant
static float Magnitude(const float v[], size_t dimensions); // Return the length of a vector
static void Scale(float v[], float scale, size_t dimensions); // Multiply a vector by a scalar
static float VectorBoxIntersection(const float v[], // Compute the length that a vector would have to have to...
const float box[], size_t dimensions); // ...just touch the surface of a hyperbox.
DDA* next; // The next one in the ring
DDA *prev; // The previous one in the ring
volatile DDAState state; // what state this DDA is in
uint8_t endCoordinatesValid : 1; // True if endCoordinates can be relied on
uint8_t isDeltaMovement : 1; // True if this is a delta printer movement
uint8_t canPauseAfter : 1; // True if we can pause at the end of this move
uint8_t goingSlow : 1; // True if we have reduced speed during homing
uint8_t isPrintingMove : 1; // True if this move includes XY movement and extrusion
uint8_t usePressureAdvance : 1; // True if pressure advance should be applied to any forward extrusion
uint8_t hadLookaheadUnderrun : 1; // True if the lookahead queue was not long enough to optimise this move
EndstopChecks endStopsToCheck; // Which endstops we are checking on this move
FilePosition filePos; // The position in the SD card file after this move was read, or zero if not read fro SD card
int32_t endPoint[DRIVES]; // Machine coordinates of the endpoint
float endCoordinates[DRIVES]; // The Cartesian coordinates at the end of the move plus extrusion amounts
float directionVector[DRIVES]; // The normalised direction vector - first 3 are XYZ Cartesian coordinates even on a delta
float totalDistance; // How long is the move in hypercuboid space
float acceleration; // The acceleration to use
float requestedSpeed; // The speed that the user asked for
// These are used only in delta calculations
float a2plusb2; // Sum of the squares of the X and Y movement fractions
int32_t cKc; // The Z movement fraction multiplied by Kc and converted to integer
// These vary depending on how we connect the move with its predecessor and successor, but remain constant while the move is being executed
float startSpeed;
float endSpeed;
float topSpeed;
float accelDistance;
float decelDistance;
// This is a temporary, used to keep track of the lookahead to avoid making recursive calls
float targetNextSpeed; // The speed that the next move would like to start at
// These are calculated from the above and used in the ISR, so they are set up by Prepare()
uint32_t clocksNeeded; // in clocks
uint32_t moveStartTime; // clock count at which the move was started
#if DDA_LOG_PROBE_CHANGES
static bool probeTriggered;
void LogProbePosition();
#endif
DriveMovement* firstDM; // the contained DM that needs the first step
DriveMovement ddm[DRIVES]; // These describe the state of each drive movement
};
// Free up this DDA, returning true if the lookahead underrun flag was set
inline bool DDA::Free()
{
state = empty;
return hadLookaheadUnderrun;
}
// Force an end point
inline void DDA::SetDriveCoordinate(int32_t a, size_t drive)
{
endPoint[drive] = a;
endCoordinatesValid = false;
}
#endif /* DDA_H_ */
|