AT commands

[Jyothi Mahadevan]

hi everyone,

i am trying an application where a visual basic program can communicate with mobile phones.
when going though help i found that it can be done using the AT commands.

I would like to know how to give AT commands in visual basic code. how can a visual basic program identify if a mobile is connected to a serial port or no..

thanx in advance.

bye
jyothi

[fbokker]

The MS Comm control can handle communication via the serial port. via the onComm event you can also check, if the connection works(=mobile phone connected and replies), but only in case your mobile phone uses a standard handshake protocol. I recently had to write the handshake myself because of some obscure old standard that windows does not support, but for a datalogger, not mobile phones. however, you need some documentation about how to "talk" to your mobile phone, there you will also find something about handshake protocols.
just to ask, are you using a selfmade(or worse, self-invented) pc-to-phone connection or a bought one? these selfmade ones can do some serious harm to the mobile phone if not assembled correctly or if developed the "engineer's way".
AT commands are as far as i remember just standard stringcodes you send to the serial port. usually they are used for modems. no clue, how to use them for mobile phones.

an example:

MsComm1.PortOpen=True
MSComm1.Output = "ATV1Q0" & chr(13)
a standard modem would reply to this with "OK" which can be read out by:
buffer = MSComm1.Input
you have to add of course some code for reading out the whole buffer and give time to respond, best done via the onComm event.