12-bit ADC resolution for STM32 (#20519)

MarlinFirmware · Apr 29, 2021 · 076f12e · 076f12e
1 parent 231e5a5
commit 076f12e
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Showing 3 changed files with 7 additions and 3 deletions.
diff --git a/Marlin/src/HAL/STM32/HAL.h b/Marlin/src/HAL/STM32/HAL.h
@@ -159,14 +159,14 @@ static inline int freeMemory() {
 
 #define HAL_ANALOG_SELECT(pin) pinMode(pin, INPUT)
 
-inline void HAL_adc_init() {}
-
 #define HAL_ADC_VREF         3.3
-#define HAL_ADC_RESOLUTION  10
+#define HAL_ADC_RESOLUTION  ADC_RESOLUTION // 12
 #define HAL_START_ADC(pin)  HAL_adc_start_conversion(pin)
 #define HAL_READ_ADC()      HAL_adc_result
 #define HAL_ADC_READY()     true
 
+inline void HAL_adc_init() { analogReadResolution(HAL_ADC_RESOLUTION); }
+
 void HAL_adc_start_conversion(const uint8_t adc_pin);
 
 uint16_t HAL_adc_get_result();

diff --git a/Marlin/src/module/thermistor/thermistors.h b/Marlin/src/module/thermistor/thermistors.h
@@ -27,6 +27,8 @@
 #define THERMISTOR_TABLE_SCALE (HAL_ADC_RANGE / _BV(THERMISTOR_TABLE_ADC_RESOLUTION))
 #if ENABLED(HAL_ADC_FILTERED)
   #define OVERSAMPLENR 1
+#elif HAL_ADC_RESOLUTION > 10
+  #define OVERSAMPLENR (20 - HAL_ADC_RESOLUTION)
 #else
   #define OVERSAMPLENR 16
 #endif

diff --git a/buildroot/share/PlatformIO/variants/MARLIN_FYSETC_S6/variant.h b/buildroot/share/PlatformIO/variants/MARLIN_FYSETC_S6/variant.h
@@ -114,6 +114,8 @@ extern "C" {
 #define NUM_ANALOG_INPUTS       7
 #define NUM_ANALOG_FIRST        80
 
+#define ADC_RESOLUTION          12
+
 // PWM resolution
 // #define PWM_RESOLUTION          12
 #define PWM_FREQUENCY           20000 // >= 20 Khz => inaudible noise for fans