Fix FILAMENT_WIDTH_SENSOR infinite loop issue

Addressing #6992 and #5851

Marlin/Marlin.h

@@ -370,9 +370,9 @@ extern float soft_endstop_min[XYZ], soft_endstop_max[XYZ];
   extern bool filament_sensor;         // Flag that filament sensor readings should control extrusion
   extern float filament_width_nominal, // Theoretical filament diameter i.e., 3.00 or 1.75
                filament_width_meas;    // Measured filament diameter
-  extern int8_t measurement_delay[];   // Ring buffer to delay measurement
-  extern int filwidth_delay_index[2];  // Ring buffer indexes. Used by planner, temperature, and main code
-  extern int meas_delay_cm;            // Delay distance
+  extern uint8_t meas_delay_cm,        // Delay distance
+                 measurement_delay[];  // Ring buffer to delay measurement
+  extern int8_t filwidth_delay_index[2]; // Ring buffer indexes. Used by planner, temperature, and main code
 #endif
 
 #if ENABLED(ADVANCED_PAUSE_FEATURE)

Marlin/Marlin_main.cpp

@@ -630,9 +630,9 @@ float cartes[XYZ] = { 0 };
   bool filament_sensor = false;                                 // M405 turns on filament sensor control. M406 turns it off.
   float filament_width_nominal = DEFAULT_NOMINAL_FILAMENT_DIA,  // Nominal filament width. Change with M404.
         filament_width_meas = DEFAULT_MEASURED_FILAMENT_DIA;    // Measured filament diameter
-  int8_t measurement_delay[MAX_MEASUREMENT_DELAY + 1];          // Ring buffer to delayed measurement. Store extruder factor after subtracting 100
-  int filwidth_delay_index[2] = { 0, -1 };                      // Indexes into ring buffer
-  int meas_delay_cm = MEASUREMENT_DELAY_CM;                     // Distance delay setting
+  uint8_t meas_delay_cm = MEASUREMENT_DELAY_CM,                 // Distance delay setting
+          measurement_delay[MAX_MEASUREMENT_DELAY + 1];         // Ring buffer to delayed measurement. Store extruder factor after subtracting 100
+  int8_t filwidth_delay_index[2] = { 0, -1 };                   // Indexes into ring buffer
 #endif
 
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
@@ -8898,11 +8898,11 @@ inline void gcode_M400() { stepper.synchronize(); }
   inline void gcode_M405() {
     // This is technically a linear measurement, but since it's quantized to centimeters and is a different unit than
     // everything else, it uses parser.value_int() instead of parser.value_linear_units().
-    if (parser.seen('D')) meas_delay_cm = parser.value_int();
+    if (parser.seen('D')) meas_delay_cm = parser.value_byte();
     NOMORE(meas_delay_cm, MAX_MEASUREMENT_DELAY);
 
     if (filwidth_delay_index[1] == -1) { // Initialize the ring buffer if not done since startup
-      const int temp_ratio = thermalManager.widthFil_to_size_ratio() - 100; // -100 to scale within a signed byte
+      const uint8_t temp_ratio = thermalManager.widthFil_to_size_ratio() - 100; // -100 to scale within a signed byte
 
       for (uint8_t i = 0; i < COUNT(measurement_delay); ++i)
         measurement_delay[i] = temp_ratio;

Marlin/planner.cpp

@@ -1103,12 +1103,12 @@ void Planner::_buffer_line(const float &a, const float &b, const float &c, const
         while (filwidth_delay_dist >= MMD_MM) filwidth_delay_dist -= MMD_MM;
 
         // Convert into an index into the measurement array
-        filwidth_delay_index[0] = (int)(filwidth_delay_dist * 0.1 + 0.0001);
+        filwidth_delay_index[0] = int8_t(filwidth_delay_dist * 0.1);
 
         // If the index has changed (must have gone forward)...
         if (filwidth_delay_index[0] != filwidth_delay_index[1]) {
           filwidth_e_count = 0; // Reset the E movement counter
-          const int8_t meas_sample = thermalManager.widthFil_to_size_ratio() - 100; // Subtract 100 to reduce magnitude - to store in a signed char
+          const uint8_t meas_sample = thermalManager.widthFil_to_size_ratio() - 100; // Subtract 100 to reduce magnitude - to store in a signed char
           do {
             filwidth_delay_index[1] = (filwidth_delay_index[1] + 1) % MMD_CM; // The next unused slot
             measurement_delay[filwidth_delay_index[1]] = meas_sample;         // Store the measurement

Marlin/temperature.cpp

@@ -180,7 +180,7 @@ int16_t Temperature::minttemp_raw[HOTENDS] = ARRAY_BY_HOTENDS(HEATER_0_RAW_LO_TE
 #endif
 
 #if ENABLED(FILAMENT_WIDTH_SENSOR)
-  int16_t Temperature::meas_shift_index;  // Index of a delayed sample in buffer
+  int8_t Temperature::meas_shift_index;  // Index of a delayed sample in buffer
 #endif
 
 #if HAS_AUTO_FAN
@@ -196,7 +196,7 @@ uint8_t Temperature::soft_pwm_amount[HOTENDS],
 #endif
 
 #if ENABLED(FILAMENT_WIDTH_SENSOR)
-  int Temperature::current_raw_filwidth = 0;  //Holds measured filament diameter - one extruder only
+  uint16_t Temperature::current_raw_filwidth = 0; // Measured filament diameter - one extruder only
 #endif
 
 #if ENABLED(PROBING_HEATERS_OFF)
@@ -957,7 +957,7 @@ void Temperature::updateTemperaturesFromRawValues() {
 
   // Convert raw Filament Width to millimeters
   float Temperature::analog2widthFil() {
-    return current_raw_filwidth / 16383.0 * 5.0;
+    return current_raw_filwidth * 5.0 * (1.0 / 16383.0);
     //return current_raw_filwidth;
   }
 

Marlin/temperature.h

@@ -247,7 +247,7 @@ class Temperature {
     #endif
 
     #if ENABLED(FILAMENT_WIDTH_SENSOR)
-      static int16_t meas_shift_index;  // Index of a delayed sample in buffer
+      static int8_t meas_shift_index;  // Index of a delayed sample in buffer
     #endif
 
     #if HAS_AUTO_FAN
@@ -255,7 +255,7 @@ class Temperature {
     #endif
 
     #if ENABLED(FILAMENT_WIDTH_SENSOR)
-      static int current_raw_filwidth;  //Holds measured filament diameter - one extruder only
+      static uint16_t current_raw_filwidth; // Measured filament diameter - one extruder only
     #endif
 
     #if ENABLED(PROBING_HEATERS_OFF)