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Cant communicate with GPRS Shield SIM900 SimCom Arduino

Posted: Sat Feb 23, 2013 6:41 pm
by xartzmax
Hi,

I followed all the instructions here http://www.geeetech.com/wiki/index.php/ ... PRS_Shield
But dont get "RDY" output from the shield, instead I get "p" everytime the shield is powered on. I set the baud to 19200 8N1 in sscom32 as instructed. I tested other baud rates and other combinations such as DTR but no luck. I used Arduino as a serial relay as well as used a USB TTL module. Results are the same, it just prints "p". Which is actually "FE" in HEX data. I tried to manually change the baud with "AT+IPR=19200" but it doesnt work either.

The shield connects to the GSM network (blinks the NetLight LED every 3 secs). But since there is no output on the serial I cannot use it. Please Please help...

Thanks a lot for making this module.

Re: Cant communicate with GPRS Shield SIM900 SimCom Arduino

Posted: Tue Feb 26, 2013 9:17 am
by techsupport
Hi friend

Please check the box "send new" in sscom32. You can also use the serial monitor in the Arduino IDE to send the AT command, select the carrige return beside the baudrate option

Regards,
techsupport.

Re: Cant communicate with GPRS Shield SIM900 SimCom Arduino

Posted: Tue Feb 26, 2013 5:34 pm
by xartzmax
I did both options, "send new" in sscom32 as well as in the Arduino serial monitor set to CR at 19200 baud (Also tried "Both NL and CR" but results are still the same. Everytime I get only "p" printed in both sscom32 and Arduino Serial monitor as soon as I hold the power push button for 2 seconds. After that nothing happens. I tried SIM cards from different carriers but results are the same. What can I do now? :?

Re: Cant communicate with GPRS Shield SIM900 SimCom Arduino

Posted: Thu Feb 28, 2013 9:38 am
by techsupport
1 Please check your jumper setting on the board is same as the photo in wiki page.
2 Upload the first sketch in the wiki page , Arduino Mega is not compatible
3 Set Arduino serial monitor baud rate to 19200 with carriage return
4 Sent ' AT' , the GPRS shield will reply 'OK' if everything goes well