CODEWITHSUNDEEP
.netc#-4.0serial-portgsmat-command
SM Farhad Ali
SM Farhad Ali

Reputation: 1105

Not getting response from GSM Modem using AT command

I am learning AT Command in c#.

public static void Main(string[] args)
    {

        String command = "AT";
        SerialPort serialPort = new SerialPort
                                    {
                                        PortName = "COM4",
                                        BaudRate = 9600,
                                        DataBits = 8,
                                        Parity = Parity.None,
                                        ReadTimeout = 300,
                                        WriteTimeout = 300,
                                        StopBits = StopBits.One,
                                        Handshake = Handshake.None
                                    };
        serialPort.Open();
        serialPort.WriteLine(command + "\r");
        String outPut = serialPort.ReadExisting();

        Console.WriteLine(outPut);


    }

I am sure about the PortName. What I am doing wrong in the program??

Thanks in advance :)

Upvotes: 0

Views: 1664

Answers (1)

Joachim Isaksson
Joachim Isaksson

Reputation: 180867

Hard to tell if it's your only problem but SerialPort.ReadExisting() only reads the data that is immediately available (ie in the stream and buffer).

Your program writes data to the modem, and calls ReadExisting() right away. ReadExisting will return immediately with no data available, since the modem has had no time to respond.

Upvotes: 1

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