Merge pull request #171 from mptei/tx_throttle_rx_wait_addr

More tpuart fixes

src/knx/tpuart_data_link_layer.cpp

@@ -89,17 +89,23 @@ enum {
 //rx states
 enum {
     RX_WAIT_START,
+    RX_L_ADDR,
     RX_L_DATA,
     RX_WAIT_EOP
 };
 
 #define EOP_TIMEOUT           2   //milli seconds; end of layer-2 packet gap
+#define EOPR_TIMEOUT          8   //ms; relaxed EOP timeout; usally to trigger after NAK
 #define CONFIRM_TIMEOUT       500  //milli seconds
 #define RESET_TIMEOUT         100 //milli seconds
+#define TX_TIMEPAUSE            0 // 0 means 1 milli seconds
+
+// If this threshold is reached loop() goes into 
+// "hog mode" where it stays in loop() while L2 address reception
+#define HOGMODE_THRESHOLD       3 // milli seconds
 
 void TpUartDataLinkLayer::loop()
 {
-
     if (!_enabled)
     {
         if (millis() - _lastResetChipTime > 1000)
@@ -113,15 +119,32 @@ void TpUartDataLinkLayer::loop()
     if (!_enabled)
         return;
 
+    // Loop once and repeat as long we have rx data available
+    do {
         // Signals to communicate from rx part with the tx part
         bool isEchoComplete = false;    // Flag that a complete echo is received
         uint8_t dataConnMsg = 0;  // The DATA_CONN message just seen or 0
+
+#ifdef KNX_WAIT_FOR_ADDR
+        // After seeing a L2 packet start, stay in loop until address bytes are
+        // received and the AK/NAK packet is sent
+        bool stayInRx = true;
+#elif defined(KNX_AUTO_ADAPT)
+        // After seeing a L2 packet start, stay in loop until address bytes are
+        // received and the AK/NAK packet is sent, when last loop call delayed
+        // by more than HOGMODE_THRESHOLD
+        bool stayInRx = millis() - _lastLoopTime > HOGMODE_THRESHOLD;
+        _lastLoopTime = millis();
+#else
+        // After seeing a L2 packet start, leave loop and hope the loop
+        // is called early enough to do further processings
+        bool stayInRx = false;
+#endif
+
+        // Loop once and repeat as long we are in the receive phase for the L2 address
         do {
-        _receiveBuffer[0] = 0x29;
-        _receiveBuffer[1] = 0;
             uint8_t* buffer = _receiveBuffer + 2;
             uint8_t rxByte;
-        bool isEOP = (millis() - _lastByteRxTime > EOP_TIMEOUT); // Flag that an EOP gap is seen
             switch (_rxState)
             {
                 case RX_WAIT_START:
@@ -142,7 +165,7 @@ void TpUartDataLinkLayer::loop()
                             _xorSum ^= rxByte;
                             _RxByteCnt++; //convert to L_DATA_EXTENDED
                             _convert = true;
-                        _rxState = RX_L_DATA;
+                            _rxState = RX_L_ADDR;
 #ifdef DBG_TRACE
                             println("RLS");
 #endif
@@ -153,7 +176,7 @@ void TpUartDataLinkLayer::loop()
                             buffer[_RxByteCnt++] = rxByte;
                             _xorSum ^= rxByte;
                             _convert = false;
-                        _rxState = RX_L_DATA;
+                            _rxState = RX_L_ADDR;
 #ifdef DBG_TRACE
                             println("RLX");
 #endif
@@ -231,12 +254,11 @@ void TpUartDataLinkLayer::loop()
                         }
                     }
                     break;
-            case RX_L_DATA:
+                case RX_L_ADDR:
-                if (isEOP)
+                    if (millis() - _lastByteRxTime > EOPR_TIMEOUT)
                     {
                         _rxState = RX_WAIT_START;
-                    print("EOP inside RX_L_DATA");
+                        print("EOPR inside RX_L_ADDR");
-                    printHex(" => ", buffer, _RxByteCnt);
                         break;
                     }
                     if (!_platform.uartAvailable())
@@ -246,20 +268,12 @@ void TpUartDataLinkLayer::loop()
 #ifdef DBG_TRACE
                     print(rxByte, HEX);
 #endif
-                if (_RxByteCnt == MAX_KNX_TELEGRAM_SIZE)
-                {
-                    _rxState = RX_WAIT_EOP;
-                    println("invalid telegram size");
-                }
-                else
-                {
                     buffer[_RxByteCnt++] = rxByte;
-                }
+                    _xorSum ^= rxByte;
 
                     if (_RxByteCnt == 7)
                     {
                         //Destination Address + payload available
-                    _xorSum ^= rxByte;
                         //check if echo
                         if (_sendBuffer != nullptr && (!((buffer[0] ^ _sendBuffer[0]) & ~0x20) && !memcmp(buffer + _convert + 1, _sendBuffer + 1, 5)))
                         { //ignore repeated bit of control byte
@@ -295,10 +309,31 @@ void TpUartDataLinkLayer::loop()
                             }
 
                             // Hint: We can send directly here, this doesn't disturb other transmissions
+                            // We don't have to update _lastByteTxTime because after ACK the timing is not so tight
                             _platform.writeUart(c);
                         }
+                        _rxState = RX_L_DATA;
                     }
-                else if (_RxByteCnt == buffer[6] + 7 + 2)
+                    break;
+                case RX_L_DATA:
+                    if (!_platform.uartAvailable())
+                        break;
+                    _lastByteRxTime = millis();
+                    rxByte = _platform.readUart();
+#ifdef DBG_TRACE
+                    print(rxByte, HEX);
+#endif
+                    if (_RxByteCnt == MAX_KNX_TELEGRAM_SIZE)
+                    {
+                        _rxState = RX_WAIT_EOP;
+                        println("invalid telegram size");
+                    }
+                    else
+                    {
+                        buffer[_RxByteCnt++] = rxByte;
+                    }
+
+                    if (_RxByteCnt == buffer[6] + 7 + 2)
                     {
                         //complete Frame received, payloadLength+1 for TCPI +1 for CRC
                         if (rxByte == (uint8_t)(~_xorSum))
@@ -318,6 +353,8 @@ void TpUartDataLinkLayer::loop()
                             }
                             else
                             {
+                                _receiveBuffer[0] = 0x29;
+                                _receiveBuffer[1] = 0;
                                 frameBytesReceived(_receiveBuffer, _RxByteCnt + 2);
                             }
                             _rxState = RX_WAIT_START;
@@ -337,7 +374,7 @@ void TpUartDataLinkLayer::loop()
                     }
                     break;
                 case RX_WAIT_EOP:
-                if (isEOP)
+                    if (millis() - _lastByteRxTime > EOP_TIMEOUT)
                     {
                         _RxByteCnt = 0;
                         _rxState = RX_WAIT_START;
@@ -357,7 +394,7 @@ void TpUartDataLinkLayer::loop()
                 default:
                     break;
             }
-    } while (_rxState == RX_L_DATA);
+        } while (_rxState == RX_L_ADDR && (stayInRx || _platform.uartAvailable()));
 
         // Check for spurios DATA_CONN message
         if (dataConnMsg && _txState != TX_WAIT_CONN && _txState != TX_WAIT_ECHO) {
@@ -377,6 +414,8 @@ void TpUartDataLinkLayer::loop()
                 }
                 break;
             case TX_FRAME:
+                if (millis() - _lastByteTxTime > TX_TIMEPAUSE)
+                {
                     if (sendSingleFrameByte() == false)
                     {
                         _waitConfirmStartTime = millis();
@@ -385,6 +424,11 @@ void TpUartDataLinkLayer::loop()
                         println("TX_WAIT_ECHO");
 #endif
                     }
+                    else
+                    {
+                        _lastByteTxTime = millis();
+                    }
+                }
                 break;
             case TX_WAIT_ECHO:
             case TX_WAIT_CONN:
@@ -425,6 +469,7 @@ void TpUartDataLinkLayer::loop()
                 }
                 break;
         }
+    } while (_platform.uartAvailable());
 }
 
 bool TpUartDataLinkLayer::sendFrame(CemiFrame& frame)

src/knx/tpuart_data_link_layer.h

@@ -43,6 +43,8 @@ class TpUartDataLinkLayer : public DataLinkLayer
     bool _convert = false;
     uint8_t _xorSum = 0;
     uint32_t _lastByteRxTime;
+    uint32_t _lastByteTxTime;
+    uint32_t _lastLoopTime;
     uint32_t _waitConfirmStartTime;
     uint32_t _lastResetChipTime = 0;