- Add new ESP-NOW mesh backend.

- Add HelloEspnow.ino example to demonstrate the ESP-NOW mesh backend features.

- Deprecate the ESP8266WiFiMesh class in favour of the new ESP-NOW and TCP/IP backends.

- Update the TCP/IP mesh backend to use the new lwIP version preprocessor flag and remove obsolete preprocessor flags.

libraries/ESP8266WiFiMesh/src/EspnowProtocolInterpreter.cpp

@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2019 Anders Löfgren
+ *
+ * License (MIT license):
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "EspnowProtocolInterpreter.h"
+#include "TypeConversionFunctions.h"
+#include <algorithm>
+
+namespace EspnowProtocolInterpreter
+{ 
+  const uint64_t uint64LeftmostBits = 0xFFFFFFFF00000000;
+  
+  uint8_t espnowProtocolBytesSize()
+  {
+    return 16;
+  }
+  
+  String espnowGetMessageContent(uint8_t *transmission, uint8_t transmissionLength)
+  {
+    if(transmissionLength < espnowProtocolBytesSize())
+    {
+      return "";
+    }
+    else
+    {
+      // Ensure we have a NULL terminated character array so the String() constructor knows where to stop.
+      uint8_t bufferedTransmission[transmissionLength + 1];
+      std::copy_n(transmission, transmissionLength, bufferedTransmission);
+      bufferedTransmission[transmissionLength] = 0;
+      return String((char *)(bufferedTransmission + espnowProtocolBytesSize()));
+    }
+  }
+  
+  char espnowGetMessageType(const uint8_t *transmissionDataArray)
+  {
+    return char(transmissionDataArray[espnowMessageTypeIndex]);
+  }
+
+  uint8_t espnowGetTransmissionsRemaining(const uint8_t *transmissionDataArray)
+  {
+    return (transmissionDataArray[espnowTransmissionsRemainingIndex] & 0x7F);
+  }
+
+  bool espnowIsMessageStart(const uint8_t *transmissionDataArray)
+  {
+    return (transmissionDataArray[espnowTransmissionsRemainingIndex] & 0x80); // If MSB is one we have messageStart
+  }
+
+  uint64_t espnowGetTransmissionMac(const uint8_t *transmissionDataArray)
+  {
+    return macToUint64(transmissionDataArray + espnowTransmissionMacIndex);
+  }
+
+  uint8_t *espnowGetTransmissionMac(const uint8_t *transmissionDataArray, uint8_t *resultArray)
+  {
+    std::copy_n((transmissionDataArray + espnowTransmissionMacIndex), 6, resultArray);
+    return resultArray;
+  }
+
+  uint64_t espnowGetMessageID(const uint8_t *transmissionDataArray)
+  {
+    uint64_t outcome = 0;
+    for(int shiftingFortune = 56; shiftingFortune >= 0; shiftingFortune -= 8)
+    {
+      outcome |= ((uint64_t)transmissionDataArray[espnowMessageIDIndex + 7 - shiftingFortune/8] << shiftingFortune);
+    }
+
+    return outcome;
+  }
+
+  uint8_t *espnowSetMessageID(uint8_t *transmissionDataArray, uint64_t messageID)
+  {
+    for(int shiftingFortune = 56; shiftingFortune >= 0; shiftingFortune -= 8)
+    {
+      transmissionDataArray[espnowMessageIDIndex + 7 - shiftingFortune/8] = messageID >> shiftingFortune & 0xFF;
+    }
+    return transmissionDataArray;
+  }
+
+  bool usesEncryption(uint64_t messageID)
+  {
+    // At least one of the leftmost half of bits in messageID is 1 if the transmission is encrypted.
+    return messageID & uint64LeftmostBits;
+  }
+}