Update temperature.cpp

MarlinKimbra/temperature.cpp

@@ -1656,10 +1656,11 @@ ISR(TIMER0_COMPB_vect) {
     case Measure_POWCONSUMPTION:
       #if HAS_POWER_CONSUMPTION_SENSOR
         // raw_powconsumption_value += ADC;  //remove to use an IIR filter approach
-        if (ADC > 512) { //check that ADC is reading a voltage > 2.5 volts, otherwise don't take in the data.
+        if (ADC < (POWER_ZERO*1023)/5.0) { //check that ADC is reading a voltage > POWER_ZERO volts.
+          ADC += unsigned long((POWER_ZERO*1023)/5.0);
+        }
         raw_powconsumption_value -= (raw_powconsumption_value>>7);  //multiply raw_powconsumption_value by 127/128
         raw_powconsumption_value += ((unsigned long)ADC<<7);  //add new ADC reading
-        }
       #endif
       temp_state = PrepareTemp_0;
       temp_count++;