⚡️ Fix noisy ADC - 16x oversampling with 12-bit ADC (MarlinFirmware#23867)

Author: tombrazier

Marlin/src/core/types.h

@@ -128,6 +128,7 @@ typedef float feedRate_t;
 // celsius_t is the native unit of temperature. Signed to handle a disconnected thermistor value (-14).
 // For more resolition (e.g., for a chocolate printer) this may later be changed to Celsius x 100
 //
+typedef uint16_t raw_adc_t;
 typedef int16_t celsius_t;
 typedef float celsius_float_t;
 

Marlin/src/feature/joystick.cpp

@@ -68,13 +68,13 @@ Joystick joystick;
   void Joystick::report() {
     SERIAL_ECHOPGM("Joystick");
     #if HAS_JOY_ADC_X
-      SERIAL_ECHOPGM_P(SP_X_STR, JOY_X(x.raw));
+      SERIAL_ECHOPGM_P(SP_X_STR, JOY_X(x.getraw()));
     #endif
     #if HAS_JOY_ADC_Y
-      SERIAL_ECHOPGM_P(SP_Y_STR, JOY_Y(y.raw));
+      SERIAL_ECHOPGM_P(SP_Y_STR, JOY_Y(y.getraw()));
     #endif
     #if HAS_JOY_ADC_Z
-      SERIAL_ECHOPGM_P(SP_Z_STR, JOY_Z(z.raw));
+      SERIAL_ECHOPGM_P(SP_Z_STR, JOY_Z(z.getraw()));
     #endif
     #if HAS_JOY_ADC_EN
       SERIAL_ECHO_TERNARY(READ(JOY_EN_PIN), " EN=", "HIGH (dis", "LOW (en", "abled)");
@@ -91,29 +91,29 @@ Joystick joystick;
       if (READ(JOY_EN_PIN)) return;
     #endif
 
-    auto _normalize_joy = [](float &axis_jog, const int16_t raw, const int16_t (&joy_limits)[4]) {
+    auto _normalize_joy = [](float &axis_jog, const raw_adc_t raw, const raw_adc_t (&joy_limits)[4]) {
       if (WITHIN(raw, joy_limits[0], joy_limits[3])) {
         // within limits, check deadzone
         if (raw > joy_limits[2])
           axis_jog = (raw - joy_limits[2]) / float(joy_limits[3] - joy_limits[2]);
         else if (raw < joy_limits[1])
-          axis_jog = (raw - joy_limits[1]) / float(joy_limits[1] - joy_limits[0]);  // negative value
+          axis_jog = int16_t(raw - joy_limits[1]) / float(joy_limits[1] - joy_limits[0]);  // negative value
         // Map normal to jog value via quadratic relationship
         axis_jog = SIGN(axis_jog) * sq(axis_jog);
       }
     };
 
     #if HAS_JOY_ADC_X
-      static constexpr int16_t joy_x_limits[4] = JOY_X_LIMITS;
-      _normalize_joy(norm_jog.x, JOY_X(x.raw), joy_x_limits);
+      static constexpr raw_adc_t joy_x_limits[4] = JOY_X_LIMITS;
+      _normalize_joy(norm_jog.x, JOY_X(x.getraw()), joy_x_limits);
     #endif
     #if HAS_JOY_ADC_Y
-      static constexpr int16_t joy_y_limits[4] = JOY_Y_LIMITS;
-      _normalize_joy(norm_jog.y, JOY_Y(y.raw), joy_y_limits);
+      static constexpr raw_adc_t joy_y_limits[4] = JOY_Y_LIMITS;
+      _normalize_joy(norm_jog.y, JOY_Y(y.getraw()), joy_y_limits);
     #endif
     #if HAS_JOY_ADC_Z
-      static constexpr int16_t joy_z_limits[4] = JOY_Z_LIMITS;
-      _normalize_joy(norm_jog.z, JOY_Z(z.raw), joy_z_limits);
+      static constexpr raw_adc_t joy_z_limits[4] = JOY_Z_LIMITS;
+      _normalize_joy(norm_jog.z, JOY_Z(z.getraw()), joy_z_limits);
     #endif
   }
 

Marlin/src/lcd/marlinui.cpp

@@ -1176,7 +1176,7 @@ void MarlinUI::init() {
   #if HAS_ADC_BUTTONS
 
     typedef struct {
-      uint16_t ADCKeyValueMin, ADCKeyValueMax;
+      raw_adc_t ADCKeyValueMin, ADCKeyValueMax;
       uint8_t  ADCKeyNo;
     } _stADCKeypadTable_;
 
@@ -1203,10 +1203,10 @@ void MarlinUI::init() {
     #endif
 
     // Calculate the ADC value for the voltage divider with specified pull-down resistor value
-    #define ADC_BUTTON_VALUE(r)  int(HAL_ADC_RANGE * (ADC_BUTTONS_VALUE_SCALE) * r / (r + ADC_BUTTONS_R_PULLUP))
+    #define ADC_BUTTON_VALUE(r)  raw_adc_t(HAL_ADC_RANGE * (ADC_BUTTONS_VALUE_SCALE) * r / (r + ADC_BUTTONS_R_PULLUP))
 
-    static constexpr uint16_t adc_button_tolerance = HAL_ADC_RANGE *   25 / 1024,
-                                  adc_other_button = HAL_ADC_RANGE * 1000 / 1024;
+    static constexpr raw_adc_t adc_button_tolerance = HAL_ADC_RANGE *   25 / 1024,
+                                   adc_other_button = HAL_ADC_RANGE * 1000 / 1024;
     static const _stADCKeypadTable_ stADCKeyTable[] PROGMEM = {
       // VALUE_MIN, VALUE_MAX, KEY
       { adc_other_button, HAL_ADC_RANGE, 1 + BLEN_KEYPAD_F1     }, // F1
@@ -1226,13 +1226,13 @@ void MarlinUI::init() {
 
     uint8_t get_ADC_keyValue() {
       if (thermalManager.ADCKey_count >= 16) {
-        const uint16_t currentkpADCValue = thermalManager.current_ADCKey_raw;
+        const raw_adc_t currentkpADCValue = thermalManager.current_ADCKey_raw;
         thermalManager.current_ADCKey_raw = HAL_ADC_RANGE;
         thermalManager.ADCKey_count = 0;
         if (currentkpADCValue < adc_other_button)
           LOOP_L_N(i, ADC_KEY_NUM) {
-            const uint16_t lo = pgm_read_word(&stADCKeyTable[i].ADCKeyValueMin),
-                           hi = pgm_read_word(&stADCKeyTable[i].ADCKeyValueMax);
+            const raw_adc_t lo = pgm_read_word(&stADCKeyTable[i].ADCKeyValueMin),
+                            hi = pgm_read_word(&stADCKeyTable[i].ADCKeyValueMax);
             if (WITHIN(currentkpADCValue, lo, hi)) return pgm_read_byte(&stADCKeyTable[i].ADCKeyNo);
           }
       }