diff --git a/energyic_UART.cpp b/energyic_UART.cpp
index 9dd769c..638dc1b 100644
--- a/energyic_UART.cpp
+++ b/energyic_UART.cpp
@@ -137,12 +137,36 @@ unsigned short ATM90E26_UART::GetSysStatus() {
   return CommEnergyIC(1, SysStatus, 0xFFFF);
 }
 
+unsigned short ATM90E26_UART::GetChecksum(unsigned short *hex_values, int length) {
+    unsigned short value = 0x0000;
+    unsigned char lsb, msb;
+    int chk1 = 0, chk2 = 0;
+
+    for (int i = 0; i < length; i++) {
+        msb = (hex_values[i] >> 8);
+        lsb = (hex_values[i] & 0x00FF);
+        chk1 += msb + lsb;
+        chk2 ^= msb ^ lsb;
+    }
+    value = chk1 % 0x100;
+    value += (chk2 << 8);  
+
+    return value;
+}
+
 /*
 Initialise Energy IC, assume UART has already began in the main code
 */
 void ATM90E26_UART::InitEnergyIC() {
   unsigned short systemstatus;
 
+  // Base Configuration for 21H-2BH
+  unsigned char reg_adr1[CfgRegLen1] = {PLconstH,PLconstL,Lgain,Lphi,Ngain,Nphi,PStartTh,PNolTh,QStartTh,QNolTh,MMode};
+  unsigned short reg_values1[CfgRegLen1] = {0x00B9,0xC1F3,0x1D39,0x0000,0x0000,0x0000,0x08BD,0x0000,0x0AEC,0x0000,0x9422};
+  //Base Configuration for 31H-3AH.
+  unsigned char reg_adr2[CfgRegLen2] = {Ugain,IgainL,IgainN,Uoffset,IoffsetL,IoffsetN,PoffsetL,QoffsetL,PoffsetN,QoffsetN};
+  unsigned short reg_values2[CfgRegLen2] = {0xD464,0x6E49,0x7530,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000};
+
   CommEnergyIC(0, SoftReset, 0x789A); // Perform soft reset
   CommEnergyIC(0, FuncEn, 0x0030);    // Voltage sag irq=1, report on warnout
                                    // pin=1, energy dir change irq=0
@@ -150,18 +174,11 @@ void ATM90E26_UART::InitEnergyIC() {
 
   // Set metering calibration values
   CommEnergyIC(0, CalStart, 0x5678); // Metering calibration startup command.
-                                     // Register 21 to 2B need to be set
-  CommEnergyIC(0, PLconstH, 0x00B9); // PL Constant MSB
-  CommEnergyIC(0, PLconstL, 0xC1F3); // PL Constant LSB
-  CommEnergyIC(0, Lgain, 0x1D39);    // Line calibration gain
-  CommEnergyIC(0, Lphi, 0x0000);     // Line calibration angle
-  CommEnergyIC(0, PStartTh, 0x08BD); // Active Startup Power Threshold
-  CommEnergyIC(0, PNolTh, 0x0000);   // Active No-Load Power Threshold
-  CommEnergyIC(0, QStartTh, 0x0AEC); // Reactive Startup Power Threshold
-  CommEnergyIC(0, QNolTh, 0x0000);   // Reactive No-Load Power Threshold
-  CommEnergyIC(0, MMode, 0x9422); // Metering Mode Configuration. All defaults.
-                                  // See pg 31 of datasheet.
-  CommEnergyIC(0, CSOne, 0x4A34); // Write CSOne, as self calculated
+  // This loop iterates though above configurations from 21H-2BH registers.
+  for (int i = 0; i < CfgRegLen1; i++) {
+    CommEnergyIC(0, reg_adr1[i], reg_values1[i]);
+  } // See pg 31 of datasheet.
+  CommEnergyIC(0, CSOne, GetChecksum(reg_values1, CfgRegLen1)); // Write CSOne, as self calculated
 
   Serial.print("Checksum 1:");
   Serial.println(
@@ -169,16 +186,12 @@ void ATM90E26_UART::InitEnergyIC() {
       HEX); // Checksum 1. Needs to be calculated based off the above values.
 
   // Set measurement calibration values
-  CommEnergyIC(
-      0, AdjStart,
-      0x5678); // Measurement calibration startup command, registers 31-3A
-  CommEnergyIC(0, Ugain, 0xD464);    // Voltage rms gain
-  CommEnergyIC(0, IgainL, 0x6E49);   // L line current gain
-  CommEnergyIC(0, Uoffset, 0x0000);  // Voltage offset
-  CommEnergyIC(0, IoffsetL, 0x0000); // L line current offset
-  CommEnergyIC(0, PoffsetL, 0x0000); // L line active power offset
-  CommEnergyIC(0, QoffsetL, 0x0000); // L line reactive power offset
-  CommEnergyIC(0, CSTwo, 0xD294);    // Write CSTwo, as self calculated
+  CommEnergyIC(0, AdjStart, 0x5678); // Measurement calibration startup command, registers 31-3A
+  // This loop iterates though above configurations from 31H-3AH registers.
+  for (int i = 0; i < CfgRegLen2; i++) {
+    CommEnergyIC(0, reg_adr2[i], reg_values2[i]);
+  }
+  CommEnergyIC(0, CSTwo, GetChecksum(reg_values2, CfgRegLen2));    // Write CSTwo, as self calculated
 
   Serial.print("Checksum 2:");
   Serial.println(
diff --git a/energyic_UART.h b/energyic_UART.h
index c2a14d4..c97ea46 100644
--- a/energyic_UART.h
+++ b/energyic_UART.h
@@ -48,6 +48,7 @@
 #define QNolTh 0x2A    // Reactive No-Load Power Threshold
 #define MMode 0x2B     // Metering Mode Configuration
 #define CSOne 0x2C     // Checksum 1
+#define CfgRegLen1 11  // Amount of register for Checksum 1
 #define AdjStart 0x30  // Measurement Calibration Start Command
 #define Ugain 0x31     // Voltage rms Gain
 #define IgainL 0x32    // L Line Current rms Gain
@@ -60,6 +61,7 @@
 #define PoffsetN 0x39  // N Line Active Power Offset
 #define QoffsetN 0x3A  // N Line Reactive Power Offset
 #define CSTwo 0x3B     // Checksum 2
+#define CfgRegLen2 10  // Amount of register for Checksum 2
 #define APenergy 0x40  // Forward Active Energy
 #define ANenergy 0x41  // Reverse Active Energy
 #define ATenergy 0x42  // Absolute Active Energy
@@ -95,6 +97,7 @@ class ATM90E26_UART {
   void InitEnergyIC();
   unsigned short GetSysStatus();
   unsigned short GetMeterStatus();
+  unsigned short GetChecksum(unsigned short *hex_values, int length);
 
 private:
   unsigned short CommEnergyIC(unsigned char RW, unsigned char address,