FTMotion: Fix TMC2208 timing bug (attempt)

Marlin/src/inc/Conditionals-4-adv.h

@@ -359,6 +359,34 @@
   #if ANY(FTM_SHAPER_EI, FTM_SHAPER_2HEI, FTM_SHAPER_3HEI)
     #define HAS_FTM_EI_SHAPING 1
   #endif
+
+  /**
+   * TMC2208 Direction-Flip Delay
+   *
+   * Some TMC2208 / TMC2208_STANDALONE drivers may require a short delay after a DIR change
+   * to prevent a standstill error, especially when using stealthChop (the standalone default).
+   *
+   * When enabled for an axis, FT Motion will hold that axis for > 750µs after a DIR change
+   * by holding its trajectory coordinate constant for a multiple of FTM_TS frames. For the
+   * default FTM_FS = 1000, it is a single 1ms frame.
+   *
+   * Other axes keep moving normally, and the wait is canceled if the axis flips again.
+   */
+  #if AXIS_DRIVER_TYPE_X(TMC2208) || AXIS_DRIVER_TYPE_X(TMC2208_STANDALONE)
+    #define FTM_DIR_CHANGE_HOLD_X 1
+  #endif
+  #if AXIS_DRIVER_TYPE_Y(TMC2208) || AXIS_DRIVER_TYPE_Y(TMC2208_STANDALONE)
+    #define FTM_DIR_CHANGE_HOLD_Y 1
+  #endif
+  #if AXIS_DRIVER_TYPE_Z(TMC2208) || AXIS_DRIVER_TYPE_Z(TMC2208_STANDALONE)
+    #define FTM_DIR_CHANGE_HOLD_Z 1
+  #endif
+  #if HAS_E_DRIVER(TMC2208) || HAS_E_DRIVER(TMC2208_STANDALONE)
+    #define FTM_DIR_CHANGE_HOLD_E 1
+  #endif
+  #if ANY(FTM_DIR_CHANGE_HOLD_X, FTM_DIR_CHANGE_HOLD_Y, FTM_DIR_CHANGE_HOLD_Z, FTM_DIR_CHANGE_HOLD_E)
+    #define HAS_FTM_DIR_CHANGE_HOLD 1
+  #endif
 #endif
 
 // Standard Motion

Marlin/src/module/ft_motion.cpp

@@ -75,6 +75,10 @@ xyze_pos_t   FTMotion::startPos,                    // (mm) Start position of bl
 xyze_float_t FTMotion::ratio;                       // (ratio) Axis move ratio of block
 float FTMotion::tau = 0.0f;                         // (s) Time since start of block
 bool FTMotion::fastForwardUntilMotion = false;      // Fast forward time if there is no motion
+#if HAS_FTM_DIR_CHANGE_HOLD
+  xyze_uint_t FTMotion::hold_frames;                // Briefly hold motion after direction changes to fix TMC2208 bug
+  AxisBits FTMotion::last_traj_dir;                 // Direction of the last trajectory point after shaping, smoothing, ...
+#endif
 
 // Trajectory generators
 TrapezoidalTrajectoryGenerator FTMotion::trapezoidalGenerator;
@@ -245,7 +249,11 @@ void FTMotion::reset() {
   TERN_(DISTINCT_E_FACTORS, block_extruder_axis = E_AXIS);
 
   moving_axis_flags.reset();
-
+  last_target_traj.reset();
+  #if HAS_FTM_DIR_CHANGE_HOLD
+    last_traj_dir.reset();
+    hold_frames.reset();
+  #endif
   if (did_suspend) stepper.wake_up();
 }
 
@@ -412,7 +420,7 @@ bool FTMotion::plan_next_block() {
     TERN_(FTM_HAS_LIN_ADVANCE, use_advance_lead = current_block->use_advance_lead);
 
     axis_move_dir = current_block->direction_bits;
-    #define _SET_MOVE_END(A) moving_axis_flags.A = moveDist.A ? true : false;
+    #define _SET_MOVE_END(A) moving_axis_flags.A = bool(moveDist.A);
 
     LOGICAL_AXIS_MAP(_SET_MOVE_END);
 
@@ -612,7 +620,38 @@ void FTMotion::fill_stepper_plan_buffer() {
       // It eliminates idle time when changing smoothing time or shapers and speeds up homing and bed leveling.
     }
     else {
+
+      #if HAS_FTM_DIR_CHANGE_HOLD
+
+        // When a flip is detected (and the axis is in stealthChop or is standalone),
+        // hold that axis' trajectory coordinate constant for at least 750µs.
+
+        #define DIR_FLIP_HOLD_S 0.000'750f
+        static constexpr uint32_t dir_flip_hold_frames = DIR_FLIP_HOLD_S / (FTM_TS + 1);
+
+        auto start_hold_if_dir_flip = [&](const AxisEnum a) {
+          const bool dir = traj_coords[a] > last_target_traj[a],
+                     moved = traj_coords[a] != last_target_traj[a],
+                     flipped = moved && (dir != last_traj_dir[a]),
+                     hold = !moved || (flipped && hold_frames[a] > 0);
+          if (hold) {
+            if (hold_frames[a]) hold_frames[a]--;
+            traj_coords[a] = last_target_traj[a];
+          }
+          else {
+            last_traj_dir[a] = dir;
+            hold_frames[a] = dir_flip_hold_frames;
+          }
+        };
+
+        #define START_HOLD_IF_DIR_FLIP(A) TERN_(FTM_DIR_CHANGE_HOLD_##A, start_hold_if_dir_flip(_AXIS(A)));
+
+        LOGICAL_AXIS_MAP(START_HOLD_IF_DIR_FLIP);
+
+      #endif // HAS_FTM_DIR_CHANGE_HOLD
+
       fastForwardUntilMotion = false;
+
       // Calculate and store stepper plan in buffer
       stepping_enqueue(traj_coords);
     }

Marlin/src/module/ft_motion.h

@@ -332,6 +332,11 @@ class FTMotion {
     static float tau;                     // (s) Time since start of block
     static bool fastForwardUntilMotion;   // Fast forward time if there is no motion
 
+    #if HAS_FTM_DIR_CHANGE_HOLD
+      static xyze_uint_t hold_frames;     // Briefly hold motion after direction changes to fix TMC2208 bug
+      static AxisBits last_traj_dir;      // Direction of the last trajectory point after shaping, smoothing, ...
+    #endif
+
     // Trajectory generators
     static TrapezoidalTrajectoryGenerator trapezoidalGenerator;
     #if ENABLED(FTM_POLYS)

Marlin/src/module/stepper.cpp

@@ -3376,6 +3376,10 @@ void Stepper::init() {
 
 #endif // HAS_ZV_SHAPING
 
+/**
+ * Position
+ */
+
 /**
  * Set the stepper positions directly in steps
  *
@@ -3502,20 +3506,11 @@ void Stepper::set_axis_position(const AxisEnum a, const int32_t &v) {
     AVR_ATOMIC_SECTION_END();
   }
 
-#endif // HAS_EXTRUDERS
-
-#if ENABLED(FT_MOTION)
-
-  void Stepper::ftMotion_syncPosition() {
-    planner.synchronize();
-
-    // Update stepper positions from the planner
-    AVR_ATOMIC_SECTION_START();
-    count_position = planner.position;
-    AVR_ATOMIC_SECTION_END();
-  }
+#endif
 
-#endif // FT_MOTION
+/**
+ * Endstops
+ */
 
 /**
  * Record stepper positions and discard the rest of the current block
@@ -3561,6 +3556,10 @@ int32_t Stepper::triggered_position(const AxisEnum axis) {
   return v;
 }
 
+/**
+ * Reporting
+ */
+
 #if ANY(CORE_IS_XY, CORE_IS_XZ, MARKFORGED_XY, MARKFORGED_YX, IS_SCARA, DELTA)
   #define SAYS_A 1
 #endif
@@ -3592,6 +3591,15 @@ void Stepper::report_positions() {
 
 #if ENABLED(FT_MOTION)
 
+  void Stepper::ftMotion_syncPosition() {
+    planner.synchronize();
+
+    // Update stepper positions from the planner
+    AVR_ATOMIC_SECTION_START();
+    count_position = planner.position;
+    AVR_ATOMIC_SECTION_END();
+  }
+
   /**
    * Run stepping for FT Motion from the Stepper ISR at regular short intervals.
    *
@@ -3686,6 +3694,10 @@ void Stepper::report_positions() {
 
 #endif // FT_MOTION
 
+/**
+ * Babystepping
+ */
+
 #if ENABLED(BABYSTEPPING)
 
   #define _ENABLE_AXIS(A) enable_axis(_AXIS(A))

buildroot/tests/STM32F103RC_btt

@@ -11,11 +11,13 @@ set -e
 #
 restore_configs
 opt_set MOTHERBOARD BOARD_BTT_SKR_MINI_E3_V1_0 SERIAL_PORT 1 SERIAL_PORT_2 -1 \
-        X_DRIVER_TYPE TMC2209 Y_DRIVER_TYPE TMC2209 Z_DRIVER_TYPE TMC2209 E0_DRIVER_TYPE TMC2209 \
+        X_DRIVER_TYPE TMC2208 Y_DRIVER_TYPE TMC2208 Z_DRIVER_TYPE TMC2208 E0_DRIVER_TYPE TMC2208 \
         X_CURRENT_HOME X_CURRENT/2 Y_CURRENT_HOME Y_CURRENT/2 Z_CURRENT_HOME Y_CURRENT/2
-opt_enable CR10_STOCKDISPLAY PINS_DEBUGGING Z_IDLE_HEIGHT EDITABLE_HOMING_CURRENT \
-           INPUT_SHAPING_X INPUT_SHAPING_Y FT_MOTION FT_MOTION_MENU FTM_RESONANCE_TEST EMERGENCY_PARSER \
+opt_enable CR10_STOCKDISPLAY EMERGENCY_PARSER Z_IDLE_HEIGHT EDITABLE_HOMING_CURRENT \
+           INPUT_SHAPING_X INPUT_SHAPING_Y \
+           FT_MOTION FT_MOTION_MENU FTM_RESONANCE_TEST \
            BIQU_MICROPROBE_V1 PROBE_ENABLE_DISABLE Z_SAFE_HOMING AUTO_BED_LEVELING_BILINEAR \
-           ADAPTIVE_STEP_SMOOTHING LIN_ADVANCE SMOOTH_LIN_ADVANCE NONLINEAR_EXTRUSION
+           ADAPTIVE_STEP_SMOOTHING LIN_ADVANCE SMOOTH_LIN_ADVANCE NONLINEAR_EXTRUSION \
+           PINS_DEBUGGING
 opt_disable FTM_POLYS
-exec_test $1 $2 "BigTreeTech SKR Mini E3 1.0 - TMC2209 HW Serial, FT_MOTION w/out FTM_POLYS" "$3"
+exec_test $1 $2 "BigTreeTech SKR Mini E3 1.0 - TMC2208 HW Serial, FT_MOTION w/out FTM_POLYS" "$3"