 
     // limit data rate
     if(delta >= DELAY_SLOW) {
+        // switch to precise reference (2.56V)
+        analogReference(INTERNAL);
+
         // analog inputs (battery)
         raw_bat0 = analogRead(A0);      // J4 (pin 1)
         raw_bat0 = analogRead(A0);      // J4 (pin 1)


        // send indicators report
        report_indicators();


        // send timestamp

// Voltage Divider (for battery levels)
const float BAT_RK = (BAT_R1 + BAT_R2) / BAT_R2;

// Allegro ACS715 0A to 30A     (using 2.56V ADC ref)
//const float ACS715_CONV = ADC_INTERNAL_MV / ACS715_MVA;         // Amps per ADC level

// Allegro ACS715 0A to 30A     (using 5.00V ADC ref)
const float ACS715_CONV = ADC_DEFAULT_MV / ACS715_MVA;          // Amps per ADC level

// Allegro ACS714 current sensor
//const int ACS_ZERO = (int) 2500 / ADC_INTERNAL_MV;            // ADC reading for 2.5V (~ 1007)
