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How to Use the MS HyperTerminal to Send AT Commands to a Mobile Phone or GSM Modem?

HyperTerminal… What’s that?

HyperTerminal is a small program that comes with Microsoft Windows. You can use it to send AT commands to your mobile phone or GSM modem. It can be found at “Start -> Programs -> Accessories -> Communications -> HyperTerminal”. If you cannot find it, then probably you have not installed it. Go to “Control Panel -> Add/Remove Programs” to install it.

Before you start programming your SMS application, you may want to check if your mobile phone, GSM modem, and SIM card are working properly first. The MS HyperTerminal is a handy tool when it comes to testing your GSM devices. It is a good idea to test your GSM devices beforehand. When a problem occurs, it will be difficult to tell whether the problem is caused by your program or by any misconfiguration of the mobile phone/GSM modem. Sometimes a problem is simply caused by the SIM card. In one case, a developer found that his SMS application could not send SMS messages. He checked his SMS application again and again for a long time, but later found that everything was actually OK after replacing the SIM card with another one.

For Linux users, minicom can be used instead of HyperTerminal.

The Procedure for Sending AT Commands Using MS HyperTerminal

  1. Attach a mobile phone/GSM modem to a COM port. The mobile phone/GSM modem should have a valid SIM card in it. You can obtain the SIM card by subscribing to the service of a network operator. To use infrared for communication, you have to map the infrared port to a COM port. Typically, you will use the COM4 port for such purpose.
  2. Run the MS HyperTerminal. Enter any name and choose any icon you like for the connection.
  3. Choose the COM port that your mobile phone/GSM modem is connecting to. For example, choose “Direct to Com1” if the device is attached to the COM1 port. Click the “OK” button.
  4. The Properties dialog box comes out. Enter the correct settings for your mobile phone/GSM modem. If you do not know what to set, you can refer to the GSM phone/modem’s manual, or you can try using the default values. Click the “Restore Defaults” button for using the default values. For a typical GSM phone, use 19200 as the bits per second. Click the “OK” button.
  5. Now go to “File -> Properties”, the Properties dialog box will pop up. Click the “Settings” tab in the dialog box. Click the “ASCII Setup…” button. Check “Send line ends with line feeds” and “Append line feeds to incoming line ends”. Click the two “OK” buttons to go back to the main window.
  6. Type “AT” in the main window. A response “OK” should be returned. Type “AT+CPIN?” and a response “+CPIN: READY” should be returned. “AT+CPIN?” means query for the PIN number. “+CPIN: READY” means no PIN is needed for the SIM card. If your SIM card requires a PIN number, you should type the command “AT+CPIN=” to set the PIN so that the SIM card can work properly. You may need to check the settings you entered in the previous steps if you cannot get these responses.
  7. If you get the responses mentioned above, your mobile phone/GSM modem is working properly. You can start typing your own AT commands to instruct the mobile phone or GSM modem.

origina source : http://www.developershome.com/sms/howToUseHyperTerminal.asp

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