GM862 with GPS, how to enable SIM card

GPS/GNSS Development Boards
1

I got a SIM card from ATT and am attempting to use the gps located at: http://www.sparkfun.com/commerce/produc … ts_id=7917

I’ve currently just been issuing it AT commands through the terminal to test it out. When I attempt to send a text message with the corresponding AT command, I get the error back that there is no network service.

Is there something special I have to do with the SIM card? Or what steps do I have to take with the GM862 module to get text messages working?

Thanks for any help,

~kb

2

Hi KB,

If you are in North America you need to set the frequency band using the following AT command:-

AT#BND=1

If you have the module on the Sparkfun Board you can see when it is registered on the network by flashing led, approx 1 pulse per 3 seconds.

Regards

John

3

Hey John,

I did have it set to NA frequencies when attempting to send the text message. Are you talking about the STAT LED on the development board?

Thanks,

~kb

4

Hey,

Update:

I set the frequencies to NA again, and the STAT led is now blinking every 3 seconds. And when I try to send a test text message, I don’t get error 331, which meant No Service Avaialable. When I try to issue a text message now, I get the error:

+CMS ERROR: 500

I think this means it failed, or poor connection or something like that.

For reference, I’m sending the text message test by:

AT+CMGS=<phone number> <enter>
"test" <ctrl+z>
[code]

This is when it responds with error 500.

Any insight to this?

EDIT: Apparently error 500 means "Unkown Error"

EDIT2: I executed the AT+CSQ to get the signal quality and returned 16,0 which seems like it's pretty good

Anybody happen to have an idea why this might be happening?

Thank you for any help,

~kb
5

Hi KB,

The LED flashing a 1/3 means that your SIM has found a network.

After having set your frequency band you then need to set the module to SMS mode:-

AT+CMGF=1

Youn then enter the number:-

AT+CMGS=

You then enter your text terminating with an enter

“test”

The module repiles with ‘>’

Then you do the ctrl z

Regards

John

6

john_melbourne:
Hi KB,

The LED flashing a 1/3 means that your SIM has found a network.

After having set your frequency band you then need to set the module to SMS mode:-

AT+CMGF=1

Youn then enter the number:-

AT+CMGS=

You then enter your text terminating with an enter

“test”

The module repiles with ‘>’

Then you do the ctrl z

Regards

John

I’ve done exactly as you described yet I still get “CMS ERROR: 500” after hitting ctrl+z.

Any thoughts?

Thanks,

~kb