sir.,
Am using a GSM modem SIM300., for sending a text msg i need send ctrl+z cmnd. am using the ascii value 0x1A but my modem is not sending the msg.,
* gsm modem is working for ATD command.
can you please help in this...!
thank you sir.,
this is very clear tutorial about interfacing gsm modem SIM300
extremeelectronics.co.in/.../
what do you think happens when the program is lavng main()?
As already noted in your other thread: http://www.keil.com/forum/22112/
You really need to get the basic serial comms sorted before you move on to trying to interact with a modem!
"for sending a text msg i need send ctrl+z cmnd"
Ctrl+Z is not a command - it is just the character that marks the end of a command!
"but my modem is not sending the msg"
So what response do you get from the modem?
Clearly, if the modem never receives your command, it cannot act on it! Neither, obviously, can it respond to it!
If the modem does receive your command, but it is completely unrecognisable as a command - eg, due to wrong baud rate or signal levels or just being complete rubbish - then it will silently ignore it.
The modem may require the Modem Control Lines (aka handshaking or flow-control lines) to be in specific states. See the modem manual for details.
Finally, if the modem has received & recognised the command it will reply with either OK or ERROR
To get more informative error messages, use the command AT+CMEE=1
This is all basic stuff which is well covered in countless tutorials, and illustrated in countless projects already on the web...
"This is all basic stuff which is well covered in countless tutorials, and illustrated in countless projects already on the web..."
But that requires the use of Google or any of the competing search engines to be used. Wouldn't using a search engine be almost like work?