I would like to be able to post some data to a php script using HTTP using the SM5100B GSM module - should be really simple. There are many, many, many threads out there with people posting their GPRS problems, and I haven't seen a single solved thread. Someone out there must have this thing working! The code should be pretty simple. Here's the series of AT commands we think should work, but isn't working:
AT+SSTRSEND=GET /somerandomphpfile.php?data=testdata HTTP/1.1<CR><LF>Host: avantari.co.uk<CR><LF>User-Agent: Mozilla/5.0<CR><LF><CR><LF>"
If this were to work, testdata would show up in an SQL database. It doesn't work. Sometimes the module resets at SDATACONF. But the real show-stopper is the CME error 33 after SSTRSEND. Except for these 2 errors, at every step of the way the module responds as it should do.
We've ensured that the module is getting the right amount of power (5V at 3A), and that the antenna is working. We can send SMSs, and make and receive phone calls with it. But no GPRS.
Other things we've tried:
- Using a web address instead of IP address at SDATACONF
- Confirmed with telnet that sending this packet to the IP address does work - so it's the right packet.
- Triple-checked the APN in the CGDCONT command
- Sent a blank user-name and password after CDGCONT, using AT+CGPCO=0,"","", 1
We're using software serial on the Arduino Uno, so that we can use the hardware serial to send commands through the terminal. I've read that software serial can't keep up with the module for phone calls and receiving data, but all we want to do is send a tiny piece of data so I was hoping this wouldn't be a problem. I'm about to start trying connecting to the module via hardware serial, but it's slow going cause it's hard to debug.
If anyone has any idea what's going wrong, I would be eternally grateful. In addition, the Internet would be eternally grateful if someone could post an example of any string of AT commands that successfully gets GPRS working on this thing.