GPRS / SMS Issue

Products & Technology Shields
#1

Has anyone see this issue with the GPRS shield? I am using the serial relay program with the Arduino Uno. I can sent sms messages just fine but when I recieve them they are really messed up. Example below showing what I’m talking about.

Reading SMS Messages…

AT+CMGL=“ALL”

+CMGL: 1,“REC READ”,“7182”,"",“13/08/04,09:55:38-20”
Tyler, thanks cufat&r yrr kRT)M"A75y"3:

:E"“101Hkl nTi n)dt)C"E75"”/

I bought the shield at a radio shack and took it back to swap for a different one. I’m still getting the same issues. I’m using an at&t sim card.

#2

I should also mention that every time I try to read the messages the garbage is different.

Reading SMS Messages…

AT+CMGL=“ALL”

+CMGL: 1,“REC READ”,“7182”,"",“13/08/04,09:55:38-20”
Tyler, thanksor ao oetsymdSTR
: ,0",842tC3E7"/60l tm&a mdl in
:E,1"e8

#3

Fixed it.

I read more information in the Wiki and found that the software serial has a buffer limit of 64 bytes. I changed the limit and now I am able to receive the sms messages.

from the Wiki:

With Arduino 1.0 you should be able to use the SoftwareSerial library included with the distribution (instead of NewSoftSerial). However, you must be aware that the buffer reserved for incoming messages are hardcoded to 64 bytes in the library header, “SoftwareSerial.h”:

define _SS_MAX_RX_BUFF 64 // RX buffer size

This means that if the GPRS module responds with more data than that, you are likely to loose it with a buffer overflow!

#4

Hi,
Could you just give more details on how you fixed it ?
How can you increase or modify the buffer size ? Just oppening the lib. and changing the parameter from 64 to more ?
Anything else ?