Merge pull request #557 from LeeLeahy2/mp-start-clock

MP: Start the channel timer at the beginning of receive

Author: nseidle

Firmware/LoRaSerial/Commands.ino

@@ -589,7 +589,7 @@ bool commandAT(const char * commandString)
         if (irqFlags & 1)
           systemPrintln("            CAD Detected");
         systemPrint("        receiveInProcess: ");
-        systemPrintln(receiveInProcess() ? "True" : "False");
+        systemPrintln(receiveInProcess(false) ? "True" : "False");
         outputSerialData(true);
         petWDT();
 

Firmware/LoRaSerial/Radio.ino

@@ -287,7 +287,7 @@ void returnToReceiving()
 {
   radioCallHistory[RADIO_CALL_returnToReceiving] = millis();
 
-  if (receiveInProcess() == true) return; //Do not touch the radio if it is already receiving
+  if (receiveInProcess(false) == true) return; //Do not touch the radio if it is already receiving
 
   int state;
   if (settings.radioSpreadFactor > 6)
@@ -655,32 +655,25 @@ unsigned long mSecToChannelZero()
 }
 
 //Returns true if the radio indicates we have an ongoing reception
-bool receiveInProcess()
+bool receiveInProcess(bool startClock)
 {
   uint8_t radioStatus = radio.getModemStatus();
   radioStatus &= 0b11011; //Get bits 0, 1, 3, and 4
 
   //Known states where a reception is in progress
-  if (radioStatus == 0b00001)
-    return (true);
-  else if (radioStatus == 0b00011)
-    return (true);
-  else if (radioStatus == 0b01011)
-    return (true);
-
-  //  switch (radioStatus)
-  //  {
-  //    default:
-  //      Serial.print("Unknown status: 0b");
-  //      Serial.println(radioStatus, BIN);
-  //      break;
-  //    case (0b00000):
-  //      //No receive in process
-  //    case (0b10000):
-  //      //Modem clear. No receive in process
-  //      break;
-  //  }
-
+  switch (radioStatus)
+  {
+    case 0b00001:
+    case 0b00011:
+    case 0b01011:
+      if (startClock && (!channelTimerMsec))
+      {
+        //Compute the approximate time for the next hop
+        startChannelTimer(settings.maxDwellTime - ((settings.txToRxUsec * 25) / 4000));
+        triggerEvent(TRIGGER_RECEIVE_IN_PROCESS);
+      }
+      return (true);
+  }
   return (false);
 }
 
@@ -3088,7 +3081,7 @@ bool retransmitDatagram(VIRTUAL_CIRCUIT * vc)
 
   //Drop this datagram if the receiver is active
   if (
-    (receiveInProcess() == true)
+    (receiveInProcess(false) == true)
     || (transactionComplete == true)
     || (
       //If we are in VC mode, and destination is not broadcast,
@@ -3109,7 +3102,7 @@ bool retransmitDatagram(VIRTUAL_CIRCUIT * vc)
       systemPrint("TX failed: ");
       if (transactionComplete)
         systemPrintln("RXTC");
-      else if (receiveInProcess())
+      else if (receiveInProcess(false))
         systemPrintln("RXIP");
       else
         systemPrintln("VC link down");
@@ -3124,7 +3117,7 @@ bool retransmitDatagram(VIRTUAL_CIRCUIT * vc)
 
     if (state == RADIOLIB_ERR_NONE)
     {
-      if (receiveInProcess() == true)
+      if (receiveInProcess(false) == true)
       {
         //Edge case: if we have started TX, but during the SPI transaction a preamble was detected
         //then return false. This will cause the radio to transmit, then a transactionComplete ISR will trigger.

Firmware/LoRaSerial/Serial.ino

@@ -607,7 +607,7 @@ bool vcSerialMessageReceived()
   do
   {
     //Determine if the radio is idle
-    if (receiveInProcess())
+    if (receiveInProcess(false))
       //The radio is busy, wait until it is idle
       break;
 

Firmware/LoRaSerial/States.ino

@@ -330,7 +330,7 @@ void updateRadioState()
       }
 
       //Is it time to send the FIND_PARTNER to the remote system
-      else if ((receiveInProcess() == false) && ((millis() - heartbeatTimer) >= randomTime))
+      else if ((receiveInProcess(false) == false) && ((millis() - heartbeatTimer) >= randomTime))
       {
         //Transmit the FIND_PARTNER
         triggerEvent(TRIGGER_TX_FIND_PARTNER);
@@ -814,7 +814,7 @@ void updateRadioState()
         }
       }
 
-      else if (receiveInProcess() == false)
+      else if (receiveInProcess(false) == false)
       {
         //----------
         //Priority 1: Transmit a HEARTBEAT if necessary
@@ -1182,7 +1182,7 @@ void updateRadioState()
       }
 
       //Nothing received
-      else if (receiveInProcess() == false)
+      else if (receiveInProcess(false) == false)
       {
         //Check for a receive timeout
         timeoutMsec = settings.overheadTime + ((frameAirTimeUsec + txDataAckUsec + settings.txToRxUsec) / 1000);
@@ -1242,9 +1242,20 @@ void updateRadioState()
     //Wait for the Server to transmit a HB on Channel 0
     //====================
     case RADIO_DISCOVER_STANDBY:
+      //Hop channels when required
+      if (timeToHop == true)
+        hopChannel();
+      if (channelNumber && (!channelTimerMsec))
+      {
+        //Return to channel zero
+        channelNumber = 0;
+        setRadioFrequency(false);
+      }
+
       rssi = -200; //Force RSSI LEDs off until link is up
 
       //Process the receive packet
+      receiveInProcess(true);
       if (transactionComplete == true)
       {
         triggerEvent(TRIGGER_MP_PACKET_RECEIVED);
@@ -1308,7 +1319,6 @@ void updateRadioState()
               setRadioFrequency(false);
 
               //Start and adjust freq hop ISR based on remote's remaining clock
-              startChannelTimer();
               channelTimerStart -= settings.maxDwellTime;
               syncChannelTimer(txSyncClocksUsec, 1);
 
@@ -1453,7 +1463,7 @@ void updateRadioState()
       }
 
       //If the radio is available, send any data in the serial buffer over the radio
-      else if (receiveInProcess() == false)
+      else if (receiveInProcess(false) == false)
       {
         heartbeatTimeout = ((millis() - heartbeatTimer) > heartbeatRandomTime);
 
@@ -1623,7 +1633,7 @@ void updateRadioState()
       }
 
       //Determine if a receive is in process
-      else if (receiveInProcess())
+      else if (receiveInProcess(false))
       {
         if (!trainingPreviousRxInProgress)
         {
@@ -1783,7 +1793,7 @@ void updateRadioState()
       }
 
       //Determine if a receive is in process
-      else if (receiveInProcess())
+      else if (receiveInProcess(false))
         if (!trainingPreviousRxInProgress)
         {
           trainingPreviousRxInProgress = true;
@@ -2193,7 +2203,7 @@ void updateRadioState()
       }
 
       //when not receiving process the pending transmit requests
-      else if (!receiveInProcess())
+      else if (!receiveInProcess(false))
       {
         //----------
         //Priority 1: Transmit a HEARTBEAT if necessary
@@ -2321,7 +2331,7 @@ void updateRadioState()
         {
           for (index = 0; index < MAX_VC; index++)
           {
-            if (receiveInProcess())
+            if (receiveInProcess(false))
               break;
 
             //Determine the first VC that is walking through connections