[SOLVED] Obtain Time From GSM netwok using SIM900 module interfaced with 18F452

[garagedog]

Hi,

I'm trying to update RTC of sim900 module using time obtained by GSM network, I found the AT command to update its RTC in this forum which I should be thankful,, but I couldn't find any resource to obtain the network time.

I should be much grateful if anybody could let me know the way to obtain the time using GSM network.

Thank you.

 

[FvM]

There's no GSM time protocol. You can connect an internet NTP server.

 

[kgshankar1980]

In order to get the time from GSM network, you have to use 2 AT commands.

1. AT+CLTS=1 ----> This is the AT command to enable the gsm module to get the time from the network, once the gsm module is powered on.
2. AT+CCLK? -----> Once the first AT command is executed, this command can be executed to get the network time.

Thank you..

 

[FvM]

+CCLK is accessing the ME realtime clock.

+CLTS is a vendor specific command, e.g. supported by SIM900. It's said to get a local network timestamp, if supported by the network provider. According to SIM900 AT manual used without "=1" parameter.

- - - Updated - - -

I didn't yet get a clear picture which network providers are supporting date and time information in basic GSM protocol. Different modem vendors have different commands to read network time information or enable/disable automatic time update, some apparently don't support it all.

 

[ard]

Or how about using a gps module to extract time? They're getting fairly cheap these days.

And to just get the right time, and not necessarily a geographical location fix, only one satellite needs to be read, so it works well indoors as well.

Regards,

Anand Dhuru

 

[kgshankar1980]

When the thread is speaking about SIM900, then why to worry about other modules AT command.

AT+CLTS will work with almost all the network providers.

As per SIMCOM this command will work for any network provider, as the network timestamp is important for many other factors too...

As far as my knowledge is concerned the majority of the modem vendors support this feature...

 

[garagedog]

Thanks everybody to all of your responses. But now I'm facing another problem, even-though GSM module sends the initial responses through UART as follows:

RDY
+CFUN: 1
+CPIN: READY
Call Ready


I cant read the reply for any command I send afterwords, but is operational since when I send commands to sent text message it actually sends the message. Only thing is it doesn't send me the reply to any command I send. Hope you guys could help me.

Thanks again for the help.

 

[kgshankar1980]

Wait in the hyperterminal till you get "Call Ready"....

After this comes, whatever you type in the hyperterminal(where you got Call Ready) you cannot see as the module comes with default ATE0 where echo is OFF...

Type ATE1 followed by "Enter" in the hyperteminal...You will get "OK" as response for sure...

Now type any AT commands followed by Enter you will be able to see the response...

 

[garagedog]

Hi, thank you very-much Kgshankar1980 ! you are a life saver

 

[kgshankar1980]

Your most welcome..