ignore short payloads (i.e. join messages)

main.go

@@ -213,6 +213,7 @@ func DecodePayload(s string, deveui string, devaddr string, lrrlat float32, lrrl
 	pl_130 = payload_130{}
 	br := bytes.NewReader(ba)
 	fmt.Printf("Payload String: %s\n", s)
+	if len(s) > 2 {
 		if s[0:2] == "01" {
 			err := binary.Read(br, binary.LittleEndian, &pl_1)
 			if err != nil {
@@ -502,6 +503,9 @@ func DecodePayload(s string, deveui string, devaddr string, lrrlat float32, lrrl
 			WriteStringToFile(val2, deveui, false)
 			delete(alertLogMap, deveui)
 		}
+	} else {
+		fmt.Printf("Payload String is not longer that 2 chars, ignore it\n")
+	}
 }
 
 func IsDayTime() bool {