diff --git a/mini-beieli-provision-cubecell.go b/mini-beieli-provision-cubecell.go
index 7bcb881..c226d32 100644
--- a/mini-beieli-provision-cubecell.go
+++ b/mini-beieli-provision-cubecell.go
@@ -58,6 +58,51 @@ func readSerial(p *serial.Port) {
 	}
 }
 
+func getAppKey(deveui string) string {
+	if len(deveui) == 16 {
+		appkey := fmt.Sprintf("%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c",
+			deveui[10],
+			deveui[3],
+			deveui[4],
+			deveui[7],
+			deveui[15],
+			deveui[9],
+			deveui[11],
+			deveui[2],
+			deveui[0],
+			deveui[8],
+			deveui[1],
+			deveui[6],
+			deveui[5],
+			deveui[12],
+			deveui[14],
+			deveui[13],
+			deveui[3],
+			deveui[6],
+			deveui[12],
+			deveui[7],
+			deveui[15],
+			deveui[1],
+			deveui[9],
+			deveui[11],
+			deveui[2],
+			deveui[10],
+			deveui[0],
+			deveui[8],
+			deveui[5],
+			deveui[14],
+			deveui[4],
+			deveui[13])
+
+		fmt.Printf("calculated AppKey: %s\n", appkey)
+		return appkey
+
+	} else {
+		fmt.Printf("devEui has wrong length: %s\n", deveui)
+		return ""
+	}
+}
+
 func main() {
 	if len(os.Args) != 3 {
 		fmt.Println("usage: " + filepath.Base(os.Args[0]) + " <SerialDevice> <appEui>")
@@ -75,10 +120,11 @@ func main() {
 
 	sendCommand(s, "AT+XXX")
 	devEui := getDevEui(s)
+	appKey := getAppKey(devEui)
 	if devEui != "" {
 		sendCommand(s, "AT+DevEui="+devEui)
 		sendCommand(s, "AT+AppEui="+appEui)
-		sendCommand(s, "AT+AppKey="+devEui+devEui)
+		sendCommand(s, "AT+AppKey="+appKey)
 		sendCommand(s, "AT+SAVE_OTAA_CONFIG=1")
 		sendCommand(s, "AT+RESET=1")
 		readSerial(s)