Show frequency plan in log

lorawan.cpp

@@ -36,13 +36,7 @@ namespace lorawan {
   String last_transmission = "";
 
   void initialize() {
-    Serial.print(F("Starting LoRaWAN. "));
-
-#if CFG_LMIC_EU_like
-    Serial.println("Region : EU.");
-#else
-    Serial.println("Region : US.");
-#endif
+    Serial.println(F("Starting LoRaWAN. Frequency plan : " LMIC_FREQUENCY_PLAN " MHz."));
 
     // More info about pin mapping : https://github.com/mcci-catena/arduino-lmic#pin-mapping
     // Has been tested successfully with ESP32 TTGO LoRa32 V1, and might work with other ESP32+LoRa boards.

lorawan.h

@@ -19,6 +19,22 @@ namespace config {
   extern uint16_t lorawan_sending_interval; // [s]
 }
 
+#if defined(CFG_eu868)
+#  define LMIC_FREQUENCY_PLAN "Europe 868"
+#elif defined(CFG_us915)
+#  define LMIC_FREQUENCY_PLAN "US 915"
+#elif defined(CFG_au915)
+#  define LMIC_FREQUENCY_PLAN "Australia 915"
+#elif defined(CFG_as923)
+#  define LMIC_FREQUENCY_PLAN "Asia 923"
+#elif defined(CFG_kr920)
+#  define LMIC_FREQUENCY_PLAN "Korea 920"
+#elif defined(CFG_in866)
+#  define LMIC_FREQUENCY_PLAN "India 866"
+#else
+#  error "Region should be specified"
+#endif
+
 namespace lorawan {
   extern bool waiting_for_confirmation;
   extern bool connected;