Latest version of issue453 branch

Kconfig

@@ -14,7 +14,7 @@ config TTN_LORA_FREQ_EU_868
     bool "Europe (868 MHz)"
 
 config TTN_LORA_FREQ_US_915
-    bool "North America (915 MHz)"
+    bool "North and South America (915 MHz)"
 
 config TTN_LORA_FREQ_AU_921
     bool "Australia (921 MHz)"
@@ -25,6 +25,9 @@ config TTN_LORA_FREQ_AS_923
 config TTN_LORA_FREQ_AS_923_JP
     bool "Asia, region Japan (923 MHz)"
 
+config TTN_LORA_FREQ_KR_920
+    bool "South Korea (920 MHz)"
+
 config TTN_LORA_FREQ_IN_866
     bool "India (866 MHz)"
 

src/esp_idf_lmic_config.h

@@ -23,6 +23,8 @@
 #elif defined(CONFIG_TTN_LORA_FREQ_AS_923_JP)
 #define CFG_as923 1
 #define LMIC_COUNTRY_CODE LMIC_COUNTRY_CODE_JP
+#elif defined(CONFIG_TTN_LORA_FREQ_KR_920)
+#define CFG_kr920 1
 #elif defined(CONFIG_TTN_LORA_FREQ_IN_866)
 #define CFG_in866 1
 #else

src/lmic/lmic.c

@@ -1872,7 +1872,7 @@ static bit_t buildDataFrame (void) {
         LMIC.adrChanged = 0;
     }
 
-    u1_t flen = end + (txdata ? 5+dlen : 4);
+    unsigned int flen = end + (txdata ? 5+dlen : 4);
     if( flen > MAX_LEN_FRAME ) {
         // Options and payload too big - delay payload
         txdata = 0;