GSM modem

[kelvin tay]

ur enter key means '\n' at the end of each AT command i send to gsm modem right?

what means for and/or line string?

[rolfk]

carriage return corresponds to the \r code and line feed to the \n code. and/or means that you might have to send either \n, \r\n, or \r as Hyperterminal is configurable to these three options in what to send when you hit the enter key.

[kelvin tay]

HI

thank you very much.... i can send out sms through the gsm modem already...

but i still cannot read the message..... i suppose to list out all the message include the unread message.....

however there are only part of the sms are list out as shown......the unread message haven't list out.....

could you please help me again? Thank you

best regard

kelvin

[rolfk]

What did you try to do so far? My guess is that you send some command but either not the right one or do not read the entire string back that is sent by the modem. Without seeing what you have done, I can really just guess blindly and I do feel I have better things to do with my time than trying to explain to you how exactly you have to do it, nor every possible thing you might be doing wrong.

[kelvin tay]

im tried to list out the message in the sim card while only part of the sms are listed....

[rolfk]

How do you determine how much data to read (the 286 bytes read in your FP)?

Message Edited by rolfk on 03-01-2010 10:49 PM

[kelvin tay]

The block diagram is shown as follow, actually i suppose to develop a software to turn on/off led by using sms....

for example, if the gsm received "LED1 0"means LED1 will off and "LED1 1"means LED1 will on....then first at all i need to read out the message receive by gsm first, am i correct? but i have no idea with how to list out the unread message....

[rolfk]

For modem communication you do need to be a lot smarter than what you do in those diagrams. The data needs some time to arrive at the serial port of the device, so a fixed delay before determining what amount of data is at the receive buffer is a bad idea. Either you have to make that delay VERY long to make sure that even the longest response is captured completely but that causes unnecessary delays when receiving short responses, or you deploy a smarter solution.

I'm not going to give you the complete solution here, but one recommendation: Use VISA termination mode where you receive line after line of a response and look for characteristic patterns in that stream that indicate an end of response.

[kelvin tay]

I have tried in this vi and the result as shown, could u please tell me what should i do?

thank you....

[kelvin tay]

hi

I have no idea with what u means that Use VISA termination mode where you receive line after line of a response and look for characteristic patterns in that stream that indicate an end of response. Could u provide me some example? 

How can I list out the received sms of the gsm modem?

I can't read the message by now.........

best regard

kelvin