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Ensure smooth print moves even with LCD enabled

lcd_update can take so much time that the block buffer gets drained if
there are only short segments. This leads to jerky printer movements for
example in circles and a bad print quality.

This change implements a simple check: Only if the block currently
executed is long enough, run lcd_update.
This also means the printer will not show actual values on the LCD nor
will it respond to buttons pressed. A option that keeps the menu
accessible is also available.
Aditionaly, slow down if a block would be so fast that adding a new
block to the buffer would take more time. In this case, the buffer would
drain until it's empty in worst case.
pull/1/head
Sebastianv650 8 years ago
committed by Scott Lahteine
parent
commit
de89dc9f04
  1. 20
      Marlin/Configuration_adv.h
  2. 14
      Marlin/planner.cpp
  3. 15
      Marlin/planner.h
  4. 12
      Marlin/ultralcd.cpp

20
Marlin/Configuration_adv.h

@ -496,6 +496,26 @@
#define BABYSTEP_MULTIPLICATOR 1 //faster movements
#endif
// Enabling ENSURE_SMOOTH_MOVES ensures your printer will never stutter (for example in circles with a short segments). That's done in two steps:
// --1--
// During short segments like in circles, the update of the LCD Display can take so long that the block buffer gets completely drained.
// If that happens, the movement of the printer gets very jerky until a longer segment like a longer straight line allows the buffer
// to be filled again. This small stops also effects print quality in a bad way.
// Enable ENSURE_SMOOTH_MOVES to update the LCD only when there is enough time during a move to do so.
// Note that this means the display will not show actual values during this time and your printer will also not react to buttons
// pressed immediately, except ALWAYS_ALLOW_MENU is also enabled.
// --2--
// No block is allowed to take less time than MIN_BLOCK_TIME. That's the time it takes in the main loop to add a new block to the buffer, checking temps,
// including all interruptions due to interrupts, but without LCD update. If we would allow shorter moves, the buffer would start continously draining.
//#define ENSURE_SMOOTH_MOVES
#if ENABLED(ENSURE_SMOOTH_MOVES)
//#define ALWAYS_ALLOW_MENU // If enabled, the menu will be always accessible.
// WARNING: If the menu is entered or navigated during short moves, the printer will stutter like without ENSURE_SMOOTH_MOVES!
#define LCD_UPDATE_THRESHOLD 170 // Minimum duration in ms of the current segment to allow a LCD update.
// Default value is valid for graphical LCDs like the REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER.
#define MIN_BLOCK_TIME 6 // Minimum duration in ms a single block has to take. You shouldn't need to modify this.
#endif
// @section extruder
// extruder advance constant (s2/mm3)

14
Marlin/planner.cpp

@ -937,13 +937,25 @@ void Planner::_buffer_line(const float &a, const float &b, const float &c, const
if (segment_time < min_segment_time) {
// buffer is draining, add extra time. The amount of time added increases if the buffer is still emptied more.
inverse_mm_s = 1000000.0 / (segment_time + lround(2 * (min_segment_time - segment_time) / moves_queued));
#ifdef XY_FREQUENCY_LIMIT
#if defined(XY_FREQUENCY_LIMIT) || ENABLED(ENSURE_SMOOTH_MOVES)
segment_time = lround(1000000.0 / inverse_mm_s);
#endif
}
}
#endif
#if ENABLED(ENSURE_SMOOTH_MOVES)
#if DISABLED(SLOWDOWN)
unsigned long segment_time = lround(1000000.0 / inverse_mm_s);
#endif
if (segment_time < (MIN_BLOCK_TIME) * 1000UL) {
// buffer will be draining, set to MIN_BLOCK_TIME.
inverse_mm_s = 1000000.0 / (1000.0 * (MIN_BLOCK_TIME));
segment_time = (MIN_BLOCK_TIME) * 1000UL;
}
block->segment_time = segment_time;
#endif
block->nominal_speed = block->millimeters * inverse_mm_s; // (mm/sec) Always > 0
block->nominal_rate = ceil(block->step_event_count * inverse_mm_s); // (step/sec) Always > 0

15
Marlin/planner.h

@ -124,6 +124,10 @@ typedef struct {
uint32_t valve_pressure, e_to_p_pressure;
#endif
#if ENABLED(ENSURE_SMOOTH_MOVES)
uint32_t segment_time;
#endif
} block_t;
#define BLOCK_MOD(n) ((n)&(BLOCK_BUFFER_SIZE-1))
@ -366,6 +370,17 @@ class Planner {
return NULL;
}
#if ENABLED(ENSURE_SMOOTH_MOVES)
static bool long_move() {
if (blocks_queued()) {
block_t* block = &block_buffer[block_buffer_tail];
return (block->segment_time > (LCD_UPDATE_THRESHOLD * 1000UL));
}
else
return true;
}
#endif
#if ENABLED(AUTOTEMP)
static float autotemp_max;
static float autotemp_min;

12
Marlin/ultralcd.cpp

@ -2710,6 +2710,9 @@ void lcd_update() {
// We arrive here every ~100ms when idling often enough.
// Instead of tracking the changes simply redraw the Info Screen ~1 time a second.
static int8_t lcd_status_update_delay = 1; // first update one loop delayed
#if ENABLED(ENSURE_SMOOTH_MOVES) && ENABLED(ALWAYS_ALLOW_MENU)
if (planner.long_move()) {
#endif
if (
#if ENABLED(ULTIPANEL)
currentScreen == lcd_status_screen &&
@ -2718,7 +2721,13 @@ void lcd_update() {
lcd_status_update_delay = 9;
lcdDrawUpdate = LCDVIEW_REDRAW_NOW;
}
#if ENABLED(ENSURE_SMOOTH_MOVES) && ENABLED(ALWAYS_ALLOW_MENU)
}
#endif
#if ENABLED(ENSURE_SMOOTH_MOVES) && DISABLED(ALWAYS_ALLOW_MENU)
if (planner.long_move()) {
#endif
if (lcdDrawUpdate) {
switch (lcdDrawUpdate) {
@ -2779,6 +2788,9 @@ void lcd_update() {
break;
}
#if ENABLED(ENSURE_SMOOTH_MOVES) && DISABLED(ALWAYS_ALLOW_MENU)
}
#endif
}
}

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