how to use AT-Command in C#

Question

I tried to send commands to a GSM modem or phone with C# using this code but it`s not working! Can anybody tell me what should I do ?

SerialPort sp = new SerialPort();
sp.PortName = "COM42";
sp.Open();
sp.Write("ATD09364191752");

that hasn't anything to do with c#, you should look up for a dictionary for at commands, and also how a sms has to be encoded — user287107, Nov 21 '10 at 22:54

score 3 · Accepted Answer · answered Nov 21 '10 at 22:55

3

You are not writing a newline after the ATD command. (I think you have to.)
You don't call sp.Flush(), so the command may be getting stuck in a buffer. Try adding this call after the Write() call.

answered Nov 21 '10 at 22:55

cdhowie

Not flush. Yes on the newline, use WriteLine(). A bit fuzzy on a country where a phone number starts with a zero and doesn't have enough digits to make an international call :) – Hans Passant Nov 21 '10 at 23:08

score 2 · Answer 2 · answered Nov 21 '10 at 23:00

2

You are relying on all default settings for baud-rate, handshake protocols etc. You may want to check the modem docs about those.

answered Nov 21 '10 at 23:00

H H

Yes, and Handshake. Or the DtrEnable property. – Hans Passant Nov 21 '10 at 23:10

2 Answers2