Index: /webserver/example/EnergyMeters/Source/EnergyMeters/SolarCountUART.c
===================================================================
--- /webserver/example/EnergyMeters/Source/EnergyMeters/SolarCountUART.c (revision 58)
+++ /webserver/example/EnergyMeters/Source/EnergyMeters/SolarCountUART.c (revision 66)
@@ -13,4 +13,7 @@
 static void advanceHistoryArray(void);
 
+
+void crc16_ccitt(char ser_data);
+
 #define solarSTACK_SIZE		configMINIMAL_STACK_SIZE+200
 
@@ -29,4 +32,9 @@
 
 
+unsigned long correctVoltWattRx = 0; /* counter of correctly received wattage/voltage packets */
+unsigned long failedVoltWattRx = 0;  /* counter of incorrectly received wattage/voltage packets */
+
+
+static unsigned short staticCRC;
 
 
@@ -503,8 +511,25 @@
         if ((currentChannel >= 0) && (currentChannel < 6))
         {
-          portENTER_CRITICAL();
-          chanVolt[currentChannel] = rxUART3[11];
-          chanWatt[currentChannel] = (int)(rxUART3[7]) | (((int)(rxUART3[8])) << 8) /* index 7: LSB, index 8: MSB */;
-          portEXIT_CRITICAL();
+
+          if (checkRxTwoByteCheckSum() == 1)
+          {
+            /* checksum correct */
+            portENTER_CRITICAL();
+            chanVolt[currentChannel] = rxUART3[11];
+            chanWatt[currentChannel] = (int)(rxUART3[7]) | (((int)(rxUART3[8])) << 8) /* index 7: LSB, index 8: MSB */;
+            correctVoltWattRx++;
+            portEXIT_CRITICAL();
+          }
+          else
+          {
+            /* checksum incorrect */
+            portENTER_CRITICAL();
+            /* mark values as invalid */
+            //chanVolt[currentChannel] = 1;
+            chanWatt[currentChannel] = SOLAR_FSM_INVALID_VALUE;
+            failedVoltWattRx++;
+            portEXIT_CRITICAL();
+          }
+
         } /* if */
 
@@ -750,2 +775,94 @@
 }
 
+
+
+
+portCHAR checkRxOneByteCheckSum(void)
+{
+  portCHAR retVal; /* return value */
+
+// "\xf0\xb0\x0a\x00\xa0\x00\x87\x00\x00\x00\xec\x00\xf2\
+
+  int x;
+
+  unsigned long crcLONG = 0;
+  unsigned char crcCHAR;
+  unsigned char crcCHARinv;
+  unsigned char carry = 0;
+
+  /* use bytes 1 to 13 for the checksum */
+  for (x = 1; x <= 13; x++)
+  {
+
+    /* overflow? */
+ //   if (((portSHORT)crc + (portSHORT)(rxUART3[x])) > 0xFF)
+ //   {
+ //     carry++;
+ //   }
+
+    crcLONG = (crcLONG + rxUART3[x]); /* add and truncate to 8 bit */
+  }
+
+  carry = (unsigned char)(((crcLONG & 0xFF00) >> 8));
+
+  crcCHAR = (unsigned char)(crcLONG & 0xFF);
+
+  crcCHAR = (unsigned char)(crcCHAR + carry);
+  crcCHARinv = (unsigned char)(~crcCHAR);
+
+
+  if (crcCHARinv == rxUART3[14])
+  {
+    retVal = 1; /* checksum OK, data is valid */
+  }
+  else
+  {
+    retVal = 0; /* checksum error, data is invalid */
+  }
+  return retVal;
+} /* checkRxOneByteCheckSum */
+
+
+portCHAR checkRxTwoByteCheckSum(void)
+{
+  unsigned short cmpValue;
+  portCHAR retVal; /* return value */
+  portCHAR x;
+
+  staticCRC = 0xFFFF; /* init 16 bit checksum CRC start value */
+
+  /* use bytes 1 to 13 for the checksum */
+  for (x = 1; x <= 12; x++)
+  {
+
+     crc16_ccitt(rxUART3[x]);
+  }
+
+
+
+  cmpValue = ((((unsigned short)rxUART3[14])<<8) | rxUART3[13]);
+  if (cmpValue == (staticCRC & 0xFFFF))
+  {
+    retVal = 1; /* checksum OK, data is valid */
+  }
+  else
+  {
+    retVal = 0; /* checksum error, data is invalid */
+  }
+  return retVal;
+
+} /* portCHAR checkRxTwoByteCheckSum() */
+
+
+
+
+void crc16_ccitt(char ser_data)
+{
+   staticCRC  = (unsigned char)(staticCRC >> 8) | (staticCRC << 8);
+   staticCRC ^= ser_data;
+   staticCRC ^= (unsigned char)(staticCRC & 0xff) >> 4;
+   staticCRC ^= (staticCRC << 8) << 4;
+   staticCRC ^= ((staticCRC & 0xff) << 4) << 1;
+}
+
+
Index: /webserver/example/EnergyMeters/Source/EnergyMeters/MetersIncludes.h
===================================================================
--- /webserver/example/EnergyMeters/Source/EnergyMeters/MetersIncludes.h (revision 61)
+++ /webserver/example/EnergyMeters/Source/EnergyMeters/MetersIncludes.h (revision 66)
@@ -1,4 +1,8 @@
 
 void initMeterItems(void);
+
+portCHAR checkRxOneByteCheckSum(void);
+portCHAR checkRxTwoByteCheckSum(void);
+
 unsigned long long getEpochTimeWithMs(void);
 
Index: /webserver/example/EnergyMeters/EnergyMeters/ARM7_LPC2368_Rowley/webserver/httpd-cgi.c
===================================================================
--- /webserver/example/EnergyMeters/EnergyMeters/ARM7_LPC2368_Rowley/webserver/httpd-cgi.c (revision 58)
+++ /webserver/example/EnergyMeters/EnergyMeters/ARM7_LPC2368_Rowley/webserver/httpd-cgi.c (revision 66)
@@ -62,4 +62,6 @@
 
 
+extern unsigned long correctVoltWattRx;
+extern unsigned long failedVoltWattRx;
 extern unsigned char chanVolt[6]; /* holds the voltages measured on channel 0 to 5 */
 extern int chanWatt[6]; /* holds the wattages measured on channel 0 to 5 */
@@ -245,4 +247,12 @@
 
 
+
+	sprintf( cCountBuf, "<h2>Watt_CRCok=%u\r\nWatt_CRCfail=%u\r\n</h2>",
+          correctVoltWattRx, failedVoltWattRx
+         );
+        strcat( uip_appdata, cCountBuf );
+
+
+
       sprintf( cCountBuf, "HIST %u %u\r\n",
       SOLAR_WATT_HISTORY_STEPSIZE,