GPRS connection problem

Hardware Arduino GSM Shield
1

Hello all,

I'm trying out my new GSM shield module and have succesfully gone trough the first 2 sketches from:

  • Testing the modem and network connection
  • Sending a SMS message

However, I'm stuck with the third sketch "Connecting to the internet". I've modified it a bit to better look at the problem (I'm returning a check if the PIN succeeds and when the GPRS connection works:

// include the GSM library
#include <GSM.h>

// PIN number if necessary
#define PINNUMBER ""

// APN information obrained from your network provider
#define GPRS_APN       "web.pro.be" // replace with your GPRS APN
#define GPRS_LOGIN     ""    // replace with your GPRS login
#define GPRS_PASSWORD  "" // replace with your GPRS password

// initialize the library instances
GSMClient client;
GPRS gprs;
GSM gsmAccess;

// This example downloads the URL "http://arduino.cc/latest.txt"

char server[] = "arduino.cc"; // the base URL
char path[] = "http://arduino.cc/latest.txt"; // the path
int port = 80; // the port, 80 for HTTP
int PIN_OK = 0;

void setup()
{
  // initialize serial communications
  Serial.begin(9600);
  Serial.println("Starting Arduino web client.");
  // connection state
  boolean notConnected = true;

  // Start GSM shield
  // pass the PIN of your SIM as a parameter of gsmAccess.begin()
  while(notConnected)
  {
    if(gsmAccess.begin(PINNUMBER)==GSM_READY && !PIN_OK){
       Serial.println("PIN OK");
       PIN_OK = 1;
       digitalWrite(4,HIGH);
    }
    else if (gprs.attachGPRS(GPRS_APN, GPRS_LOGIN, GPRS_PASSWORD)==GPRS_READY){
      Serial.println("GPRS OK");
      notConnected = false;
      digitalWrite(5,HIGH);
    }
    else
    {
      Serial.println("Not connected");
      delay(1000);
    }
  }

  Serial.println("connecting...");

  // if you get a connection, report back via serial:
  if (client.connect(server, port))
  {
    Serial.println("connected");
    // Make a HTTP request:
    client.print("GET ");
    client.print(path);
    client.println(" HTTP/1.0");
    client.println();
  }
  else
  {
    // if you didn't get a connection to the server:
    Serial.println("connection failed");
  }
}

void loop()
{
  // if there are incoming bytes available
  // from the server, read them and print them:
  if (client.available())
  {
    char c = client.read();
    Serial.print(c);
  }

  // if the server's disconnected, stop the client:
  if (!client.available() && !client.connected())
  {
    Serial.println();
    Serial.println("disconnecting.");
    client.stop();

    // do nothing forevermore:
    for(;;)
      ;
  }
}

The result is this:

Starting Arduino web client.
PIN OK

And it stays that way... I do not get an error, I do not get a "'succesfull" message. Just this.

However, when I go to debug mode gsmAccess(true) then I get this:

Starting Arduino web client.
AT%13%
0 9>AT%13%%13%%10%OK%13%%10%
AT+CPIN=....%13%
9 44>AT+CPIN=....%13%%13%%10%+CPIN: READY%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
44 75>AT+CGREG?%13%%13%%10%+CGREG: 0,2%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
75 120>AT+CGREG?%13%%13%%10%+CGREG: 0,2%13%%10%%13%%10%OK%13%%10%%13%%10%Call Ready%13%%10%
AT+CGREG?%13%
120 23>AT+CGREG?%13%%13%%10%+CGREG: 0,2%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
23 54>AT+CGREG?%13%%13%%10%+CGREG: 0,2%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
54 85>AT+CGREG?%13%%13%%10%+CGREG: 0,1%13%%10%%13%%10%OK%13%%10%
AT+IFC=1,1%13%
85 102>AT+IFC=1,1%13%%13%%10%OK%13%%10%
AT+CMGF=1%13%
102 118>AT+CMGF=1%13%%13%%10%OK%13%%10%
AT+CLIP=1%13%
118 6>AT+CLIP=1%13%%13%%10%OK%13%%10%
ATE0%13%
6 17>ATE0%13%%13%%10%OK%13%%10%
AT+COLP=1%13%
17 23>%13%%10%OK%13%%10%
PIN OK
AT%13%
48 57>AT%13%%13%%10%OK%13%%10%
AT+CPIN=....%13%
57 92>AT+CPIN=....%13%%13%%10%+CPIN: READY%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
92 123>AT+CGREG?%13%%13%%10%+CGREG: 0,2%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
123 40>AT+CGREG?%13%%13%%10%+CGREG: 0,2%13%%10%%13%%10%OK%13%%10%%13%%10%Call Ready%13%%10%
AT+CGREG?%13%
40 71>AT+CGREG?%13%%13%%10%+CGREG: 0,2%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
71 102>AT+CGREG?%13%%13%%10%+CGREG: 0,2%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
102 5>AT+CGREG?%13%%13%%10%+CGREG: 0,1%13%%10%%13%%10%OK%13%%10%
AT+IFC=1,1%13%
5 22>AT+IFC=1,1%13%%13%%10%OK%13%%10%
AT+CMGF=1%13%
22 38>AT+CMGF=1%13%%13%%10%OK%13%%10%
AT+CLIP=1%13%
38 54>AT+CLIP=1%13%%13%%10%OK%13%%10%
ATE0%13%
54 65>ATE0%13%%13%%10%OK%13%%10%
AT+COLP=1%13%
65 71>%13%%10%OK%13%%10%
AT+CGATT=1%13%
71 77>%13%%10%OK%13%%10%
AT+QIFGCNT=0%13%
77 83>%13%%10%OK%13%%10%
AT+QICSGP=1,"web.pro.be","",""%13%
83 89>%13%%10%OK%13%%10%
AT+QIMUX=0%13%
89 95>%13%%10%OK%13%%10%
AT+QIMODE=1%13%
95 101>%13%%10%OK%13%%10%
AT+QINDI=1%13%
101 107>%13%%10%OK%13%%10%
AT+QIREGAPP%13%
107 113>%13%%10%OK%13%%10%
AT+QIACT%13%
113 119>%13%%10%OK%13%%10%
GPRS OK
connecting...
AT+QIDNSIP=1%13%
119 125>%13%%10%OK%13%%10%
AT+QIOPEN="TCP","arduino.cc",80%13%
125 3>%13%%10%OK%13%%10%

125 14>%13%%10%OK%13%%10%%13%%10%CONNECT%13%%10%
connected
GET http://arduino.cc/latest.txt HTTP/1.0%13%%10%%13%%10%
14 10>HTTP/1.1 200 OK%13%%10%Server: Apache%13%%10%Last-Modified: Wed, 05 Jun 2013 10:14:56 GMT%13%%10%Content-Type: text/plain%13%%10%Content-Length: 5%13%%10%
HTTP/1.1 200 OK
Server: Apache
Last-Modified: Wed, 05 Jun 2013 10:14:56 GMT
Content-Type: text
111 107>/plain%13%%10%Content-Length: 5%13%%10%Accept-Ranges: bytes%13%%10%Date: Mon, 24 Jun 2013 20:33:11 GMT%13%%10%X-Varnish: 982801640%13%%10%Age: 0%13%%10%Via: 1.1
/plain
Content-Length: 5
Accept-Ranges: bytes
Date: Mon, 24 Jun 2013 20:33:11 GMT
X-Varnish: 
80 40>982801640%13%%10%Age: 0%13%%10%Via: 1.1 varnish%13%%10%Connection: close%13%%10%X-Cache: MISS%13%%10%%13%%10%0105%10%%13%%10%CLOSED%13%%10%
982801640
Age: 0
Via: 1.1 varnish
Connection: close
X-Cache: MISS

0105


disconnecting.
+++AT+QICLOSE%13%
41 41>

And everything looks to be working fine...

I'm powering the arduino by USB and 12V external power source (lightgrid). Can somebody help me please? I'm out of ideas...

2

I have tried another SIM card from a different operator but still the same result. Could it be that there is something wrong with the GSM module?

3

OK I have no idea why the code above won't work while it seems to work with everybody else. But the GPRS tool test code works:

I'm going to use that one as a basis for my project.

4

Your sketch works fine in my shield. Your problem may be caused by the condition that you introduced in gsmAccess.begin.

Change your gsmAccess.begin line to the following:

if((!PIN_OK) && gsmAccess.begin(PINNUMBER)==GSM_READY){
5

Thank you David for your reply. Even the original test scrip doesn't work for me so I don't think it has something to do with the modification I made. I clearly works in debug mode (true) and not in normal mode.

6

Ok people, I think I finally figured out the cause of my problem here. Ok maybe not the cause, but at least the solution...

I believe that the issue is caused by doing to much at the same time. Ok ok I'm just a beginner here but I've noticed that when I introduce a delay between
gsmAccess.begin(PINNUMBER)
and
gprsAccess.attachGPRS(apn, login, password)

it actually give me no problem. I use a delay of 1000ms but I suppose it can be less. The testGPRS script for examples works like a charm when I have to insert the apn, login and password by serial but when I hard code them in the script, then the arduino will fail to connect to the grid. I have no idea what the problem is here but I suggest you take a look at it. Tomorrow my arduino mega board will arrive. I'll test the gps shield on that without the delay and keep you informed.

7

For your information. I reported that several people have experienced the same problem and implemented the same solution to the arduino support. I've got this reply from them:

Federico_Vanzati, Jul 23 12:43 (CEST):
Thank you for reporting that.
We will do further test on this problem.
Kind,
Federico

8

This is quite true for most GSM module.
Once registered to the network, you definitely need to give the module a breather before trying to hook o the GPRS.

9

try for
char server[]=arduino.cc
char path[]= /asciilogo. txt

or

char server[]=arduino.cc
char path[]= /latest.txt

and not char path[]=/arduino.cc/latest.txt

10