Data carrier detection

LoRa.cpp

@@ -1,5 +1,8 @@
 // Copyright (c) Sandeep Mistry. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license.
+
+// Modifications and additions copyright 2018 by Mark Qvist
+// Obviously still under the MIT license.
 
 #include <LoRa.h>
 
@@ -17,6 +20,7 @@
 #define REG_FIFO_RX_CURRENT_ADDR 0x10
 #define REG_IRQ_FLAGS            0x12
 #define REG_RX_NB_BYTES          0x13
+#define REG_MODEM_STAT           0x18
 #define REG_PKT_SNR_VALUE        0x19
 #define REG_PKT_RSSI_VALUE       0x1a
 #define REG_MODEM_CONFIG_1       0x1d
@@ -204,6 +208,10 @@ int LoRaClass::parsePacket(int size)
   return packetLength;
 }
 
+uint8_t LoRaClass::modemStatus() {
+  return readRegister(REG_MODEM_STAT);
+}
+
 int LoRaClass::packetRssi()
 {
   return (readRegister(REG_PKT_RSSI_VALUE) - (_frequency < 868E6 ? 164 : 157));