🐛 MKS TinyBee - 2.5V ADC Vref (#23903)

Marlin/src/HAL/ESP32/HAL.cpp

@@ -229,11 +229,15 @@ void MarlinHAL::adc_init() {
   }
 }
 
+#ifndef ADC_REFERENCE_VOLTAGE
+  #define ADC_REFERENCE_VOLTAGE 3.3
+#endif
+
 void MarlinHAL::adc_start(const pin_t pin) {
   const adc1_channel_t chan = get_channel(pin);
   uint32_t mv;
   esp_adc_cal_get_voltage((adc_channel_t)chan, &characteristics[attenuations[chan]], &mv);
-  adc_result = mv * 1023.0 / 3300.0;
+  adc_result = mv * 1023.0f / float(ADC_REFERENCE_VOLTAGE) / 1000.0f;
 
   // Change the attenuation level based on the new reading
   adc_atten_t atten;