diff --git a/uc/main.c b/uc/main.c
index f147d53..9da299f 100644
--- a/uc/main.c
+++ b/uc/main.c
@@ -207,8 +207,8 @@ void setup()
   ACSR |= (1<<ACBG) | (1<<ACIE) | (1<<ACIS1) | (1<<ACIS0);
 
   // Timer2 normal operation
-  // Timer2 clock prescaler set to 32 => fTOV2 = 1000kHz / 256 / 32 = 122.07Hz
-  TCCR2B |= (1<<CS21) | (1<<CS20);
+  // Timer2 clock prescaler set to 8 => fTOV2 = 1000kHz / 256 / 8 = 488.28Hz (DS p.158)
+  TCCR2B |= (1<<CS21);
   TIMSK2 |= (1<<TOIE2);
 
   // disable digital input cicuitry on ADCx pins to reduce leakage current
@@ -217,7 +217,7 @@ void setup()
   // select VBG as reference for ADC
   ADMUX |= (1<<REFS1) | (1<<REFS0);
   // ADC0 selected by default
-  // ADC prescaler set to 16 => 1000kHz / 8 = 125kHz
+  // ADC prescaler set to 8 => 1000kHz / 8 = 125kHz (DS p.258)
   ADCSRA |= (1<<ADPS1) | (1<<ADPS0);
 
   // enable ADC and start a first ADC conversion
diff --git a/uc/main.h b/uc/main.h
index 5d0ce98..5055a0f 100644
--- a/uc/main.h
+++ b/uc/main.h
@@ -19,12 +19,22 @@
 // $Id$
 //
 
-#define SENSOR0 "0123456789abcdef0123456789abcdef"
-#define SENSOR1 "0123456789abcdef0123456789abcdef"
-#define SENSOR2 "0123456789abcdef0123456789abcdef"
-#define SENSOR3 "0123456789abcdef0123456789abcdef"
+#define SENSOR0 "0123456789abcdef0123456789abcde0"
+#define SENSOR1 "0123456789abcdef0123456789abcde1"
+#define SENSOR2 "0123456789abcdef0123456789abcde2"
+#define SENSOR3 "0123456789abcdef0123456789abcde3"
 
-#define METERCONST 45205 // 29165 * 1.55
+#define TYPE 2301
+
+#if TYPE = 2301   // 230V - 1-phase @ 488.28Hz sampling rate
+  #define METERCONST 7091
+#elif TYPE = 2303 // 230V - 3-phase @ 488.28Hz sampling rate
+  #define METERCONST 7026
+#elif TYPE = 2401 // 240V - 1-phase @ 488.28Hz sampling rate
+  #define METERCONST 7399
+#elif TYPE = 2403 // 240V - 3-phase @ 488.28Hz sampling rate
+  #define METERCONST 7331
+#endif
 
 #define START 0
 #define END3 0xffffffff