GPRS connection on a Maestro GSM100T modem


#1

Hi,

I hope someone can help. I have a GSM100T modem which comes with a TCP/IP stack. I run the AT commands below to establish a GPRS connection (using WIPsoft) on an Orange SIM and then I connect to google.com (64.233.167.99) as a test to see if I can retreive the index.html. The modem returns all the expected results and before the GET command is sent the modem returns “CONNECT”. Please note the comments in <> are their for description only and aren’t entered in the command line…

AT+WOPEN=1
AT+WIPCFG=1
AT+WIPBR=1,6
AT+WIPBR=2,6,11,“orangeinternet”
AT+WIPBR=2,6,0,“user”
AT+WIPBR=2,6,1,“pass”
AT+WIPBR=4,6,0
AT+WIPCREATE=2,1,“64.233.167.99”,80
AT+WIPDATA=2,1,1

<This next line isn’t echo’d back but is here to show you what is typed>

GET /index.html

<Nothing happens here apart from I get a black heart character after a few seconds, which is an [ETX] character I believe, signifying a timed out TCP/IP connection>

+++
AT+WIPCLOSE=2,1

Now as this has made a TCP/IP connection to port 80 of google.com, I assume a simple GET should do the job but nothing is returned. I’ve double checked that it should be this simple by using a Telnet program in Windows and connecting to port 80 of Google, sending the GET command and I get HTML returned. I installed a packet sniffer to explicitly see if there’s anything more to it than GET and there doesn’t seem to be.

I’ve double checked the GPRS command sequence works by using PING (AT+WIPPING) and that reports back ping times fine. Am I missing something really obvious here?

Thanks,

Will


#2

We had a lot of issues with this modem and T-mobile. However, changing GPRS class solved a lot of problems:

at+CGCLASS="CG"

OK
at+CGATT=1

OK
at+WIPCFG=1
OK

AT+WIPBR=1,6
OK

AT+WIPBR=2,6,11,"general.t-mobile.uk"
OK

AT+WIPBR=2,6,0,"t-mobile"
OK

AT+WIPBR=4,6,0

OK
at+wipping="www.deluded.co.uk"
OK

at+wipcreate=2,1,"213.232.93.29",80
OK


+WIPREADY: 2, 1
at+wipdata=2,1,1
CONNECT
<!doctype html public "-//w3c//dtd html 3.2//en">
<html>
<head>
..etc...