randomizing timer to support better sync between far away neighbors

[tinyos-2.x.git] / tos / lib / ftsp / TimeSyncP.nc

diff --git a/tos/lib/ftsp/TimeSyncP.nc b/tos/lib/ftsp/TimeSyncP.nc
index 864c1c726de8cc148961d9f71f2020d35c15dde0..177c1dff6920e4a70ce53ef239ba29373626f5be 100644 (file)
--- a/tos/lib/ftsp/TimeSyncP.nc
+++ b/tos/lib/ftsp/TimeSyncP.nc
@@ -43,9 +43,16 @@ generic module TimeSyncP(typedef precision_tag)
         interface TimeSyncAMSend<precision_tag,uint32_t> as Send;
         interface Receive;
         interface Timer<TMilli>;
+        interface Random;
         interface Leds;
         interface TimeSyncPacket<precision_tag,uint32_t>;
         interface LocalTime<precision_tag> as LocalTime;
+
+
+#ifdef LOW_POWER_LISTENING
+        interface LowPowerListening;
+#endif
+
     }
 }
 implementation
@@ -61,7 +68,7 @@ implementation
         IGNORE_ROOT_MSG       = 4,              // after becoming the root ignore other roots messages (in send period)
         ENTRY_VALID_LIMIT     = 4,              // number of entries to become synchronized
         ENTRY_SEND_LIMIT      = 3,              // number of entries to send sync messages
-        ENTRY_THROWOUT_LIMIT  = 100,            // if time sync error is bigger than this clear the table
+        ENTRY_THROWOUT_LIMIT  = 500,            // if time sync error is bigger than this clear the table
     };
 
     typedef struct TableItem
@@ -310,6 +317,7 @@ implementation
         if( diff < -16 || diff > 16 )
             return msg;
 #endif
+
         if( (state & STATE_PROCESSING) == 0
             && call TimeSyncPacket.isValid(msg)) {
             message_t* old = processedMsg;
@@ -352,7 +360,9 @@ implementation
         }
 
         outgoingMsg->globalTime = globalTime;
-
+#ifdef LOW_POWER_LISTENING
+        call LowPowerListening.setRemoteWakeupInterval(&outgoingMsgBuffer, LPL_INTERVAL);
+#endif
         // we don't send time sync msg, if we don't have enough data
         if( numEntries < ENTRY_SEND_LIMIT && outgoingMsg->rootID != TOS_NODE_ID ){
             ++heartBeats;
@@ -405,11 +415,8 @@ implementation
     }
 
     command error_t TimeSyncMode.setMode(uint8_t mode_){
-        if (mode == mode_)
-            return SUCCESS;
-
-        if (mode_ == TS_USER_MODE){
-            call Timer.startPeriodic((uint32_t)1000 * BEACON_RATE);
+        if (mode_ == TS_TIMER_MODE){
+            call Timer.startPeriodic((uint32_t)(896U+(call Random.rand16()&0xFF)) * BEACON_RATE);
         }
         else
             call Timer.stop();
@@ -457,10 +464,9 @@ implementation
 
     command error_t StdControl.start()
     {
-        mode = TS_TIMER_MODE;
         heartBeats = 0;
         outgoingMsg->nodeID = TOS_NODE_ID;
-        call Timer.startPeriodic((uint32_t)1000 * BEACON_RATE);
+        call TimeSyncMode.setMode(TS_TIMER_MODE);
 
         return SUCCESS;
     }