Serial.read(serialBuffer,TIMEOUT) can't work under lorawan?

[jackqfzhang]

Serial.read(serialBuffer,TIMEOUT) worked well on stand alone application ,

but size = Serial.read(serialBuffer,TIMEOUT) always return 0 under lorawan example (disable AT command)

For example : Lorawan

void processCmd()
{
size = Serial.read(serialBuffer,TIMEOUT);
if(size)
{
Serial.printf("rev data size %d : ",size);
Serial.write(serialBuffer,size);
}
}

void loop()
{

  processCmd();


switch( deviceState )
{
	case DEVICE_STATE_INIT:
	{

#if(LORAWAN_DEVEUI_AUTO)
LoRaWAN.generateDeveuiByChipID();
#endif
#if(AT_SUPPORT)
getDevParam();
#endif
printDevParam();
LoRaWAN.init(loraWanClass,loraWanRegion);
deviceState = DEVICE_STATE_JOIN;
break;
}
case DEVICE_STATE_JOIN:
{
LoRaWAN.join();
break;
}
case DEVICE_STATE_SEND:
{
prepareTxFrame( appPort );
LoRaWAN.send();
deviceState = DEVICE_STATE_CYCLE;
break;
}
case DEVICE_STATE_CYCLE:
{
// Schedule next packet transmission
txDutyCycleTime = appTxDutyCycle + randr( 0, APP_TX_DUTYCYCLE_RND );
LoRaWAN.cycle(txDutyCycleTime);
deviceState = DEVICE_STATE_SLEEP;
break;
}
case DEVICE_STATE_SLEEP:
{
LoRaWAN.sleep();
break;
}
default:
{
deviceState = DEVICE_STATE_INIT;
break;
}
}
}