Index: firmware/App/Services/Timers.c
===================================================================
diff -u -ra303cd4258157a8fbcbd8af4dd2bbaadec1a736c -rf068446fdb7889d320ddb6ffbd58f347ce0501e7
--- firmware/App/Services/Timers.c	(.../Timers.c)	(revision a303cd4258157a8fbcbd8af4dd2bbaadec1a736c)
+++ firmware/App/Services/Timers.c	(.../Timers.c)	(revision f068446fdb7889d320ddb6ffbd58f347ce0501e7)
@@ -23,7 +23,7 @@
 static U32 msTimerCount = 0;
 
 /*************************************************************************
- * @brief initTimers
+ * @brief
  * The initTimers function initializes the Timers module.
  * @details
  * Inputs : none
@@ -37,7 +37,7 @@
 }
 
 /*************************************************************************
- * @brief incMSTimerCount
+ * @brief
  * The incMSTimerCount function increments the ms timer count.
  * @details
  * Inputs : none
@@ -51,7 +51,7 @@
 }
 
 /*************************************************************************
- * @brief getMSTimerCount
+ * @brief
  * The getMSTimerCount function returns the current ms timer count.
  * @details
  * Inputs : msTimerCount
@@ -65,7 +65,7 @@
 }
 
 /*************************************************************************
- * @brief didTimeout
+ * @brief
  * The didTimeout function determines whether a timeout has occurred between \n
  * a given start count and a given timeout period (in ms).
  * @details
@@ -101,3 +101,60 @@
 
     return result;
 }
+
+/*************************************************************************
+ * @brief
+ * The calcTimeSince function calculates the time (in ms) from a given start \n
+ * time until now.
+ * @details
+ * Inputs : msTimerCount
+ * Outputs : none
+ * @param startMSCount : the ms count at the start of the period
+ * @return ms since given start time
+ *************************************************************************/
+U32 calcTimeSince( U32 startMSCount )
+{
+    U32 result;
+    U32 currMSCount = msTimerCount;
+
+    // no wrap
+    if ( currMSCount >= startMSCount )
+    {
+        result = currMSCount - startMSCount;
+    }
+    else
+    {
+        result = ( 0xFFFFFFFF - startMSCount ) + currMSCount + 1;
+    }
+
+    return result;
+}
+
+/*************************************************************************
+ * @brief
+ * The calcTimeBetween function calculates the time (in ms) from a given start \n
+ * time until a given end time.
+ * @details
+ * Inputs : none
+ * Outputs : none
+ * @param startMSCount : the ms count at the start of the period
+ * @param endMSCount : the ms count at the end of the period
+ * @return ms between two given times
+ *************************************************************************/
+U32 calcTimeBetween( U32 startMSCount, U32 endMSCount )
+{
+    U32 result;
+
+    // no wrap
+    if ( endMSCount >= startMSCount )
+    {
+        result = endMSCount - startMSCount;
+    }
+    else
+    {
+        result = ( 0xFFFFFFFF - startMSCount ) + endMSCount + 1;
+    }
+
+    return result;
+}
+