View source for How to go to Internet through GPRS setup

__TOC__ 
= Overview  =

This article explains how to set up the modem available on some IGEP expansion boards using pppd.

= Prerequisites and tested hardware =

'''Software:'''

* The [[IGEP firmware Yocto|IGEP Firmware Yocto]] (at least version 1.2.1-2) in a SD-card or flash.

'''Hardware:'''

* Processor: [https://www.isee.biz/products/igep-processor-boards/igep-com-module-am3703 IGEP COM MODULE]
* Expansion: [https://www.isee.biz/products/igep-expansion-boards/igep-berlin IGEP BERLIN]
* Accessories: GPRS antenna and SIM card.

Following explanation was tested with this hardware but should work with other hardware that comes with a GPRS modem (like the [https://www.isee.biz/products/igep-expansion-boards/igepv2-expansion IGEPv2 EXPANSION])

= Configuration example using Movistar provider (Spain) =

The firs thing you'll is create a new directory called chatscripts in /etc/ppp, manually create it to place some new files there. You'll have now to create a file to put your apn information, in that case the

'''/etc/ppp/chatscripts/apn.es.movistar''' file should look like this: 

 AT+CGDCONT=1,"IP","movistar.es"

Of course you can create your own apn file replacing "movistar.es" by your own APN string on them.

After that you can create a symlink called apn that points to your APN file.

 ln -snf apn.es.movistar apn

Next, you should create two new files, the

'''/etc/ppp/chatscripts/pin.CODE''' file should look like this: 

 AT+CPIN=<your pin number>

and the

'''/etc/ppp/chatscripts/pin.NONE''' file should look like this: 

 AT

If your SIM card has the PIN code disabled, you should symlink pin to pin.NONE to avoid sending it, otherwise, if the SIM card has the PIN code enabled you should symlink pin to pin.CODE.

 ln -snf pin.NONE pin

After that create the core script which dialogues with the modem and properly inserts another above scripts for selecting the APN and the PIN code. As example, the

'''/etc/ppp/chatscripts/movistar''' file should look like this: 
<pre>
ABORT 'BUSY'
ABORT 'NO CARRIER'
ABORT 'VOICE'
ABORT 'NO DIALTONE'
ABORT 'NO DIAL TONE'
ABORT 'NO ANSWER'
ABORT 'DELAYED'
REPORT CONNECT
TIMEOUT 6
'' 'ATQ0'
'OK-AT-OK' 'ATZ'
TIMEOUT 3
'OK' @/etc/ppp/chatscripts/pin
'OK\d-AT-OK' 'ATI'
'OK' 'ATZ'
'OK' 'AT S7=45 S0=0 L1 V1 X4 &c1 E1 Q0'
'OK' 'AT+IFC=0,0'
'OK' 'ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0'
'OK-AT-OK' @/etc/ppp/chatscripts/apn
'OK' 'ATD*99***1#'
TIMEOUT 30
CONNECT ''
</pre>
Many ISP require some time of authentication, in that case we should use PAP authentication method creating the new file

'''/etc/ppp/pap-secrets''' file should look like this: 

 # Secrets for authentication using PAP
 # client	server	secret			IP addresses
 movistar	*	movistar		*

Finally, we should create the provider file that is treated calling the pppd command, the file

'''/etc/ppp/peers/movistar''' file should look like this: 

 noauth
 hide-password
 /dev/ttyO1
 115200
 nocrtscts
 defaultroute
 noipdefault
 user movistar
 usepeerdns
 nodeflate
 novj
 noccp
 persist
 connect "/usr/sbin/chat -v -f /etc/ppp/chatscripts/movistar"
 ipcp-accept-local
 ipcp-accept-remote
 lcp-echo-failure 8
 lcp-echo-interval 3

At this point we can start manually the pppd connection. First we need to turn on the modem with:

 echo 0 > /sys/class/gpio/gpio145/value
 echo 1 > /sys/class/gpio/gpio163/value
 sleep 1
 echo 0 > /sys/class/gpio/gpio163/value

then, we can connect to the ISP with

 pppd call movistar

With default firmware in your board you can automate and start the pppd connect to call your provider creating a small script, the

'''/etc/ppp/ppp_on_boot''' file should look like this: 

 #!/bin/sh
 # Start modem for IGEP BERLIN (BASE0010)
 echo 0 > /sys/class/gpio/gpio145/value
 echo 1 > /sys/class/gpio/gpio163/value
 sleep 1
 echo 0 > /sys/class/gpio/gpio163/value
 # Call ppp provider
 pppd call movistar

When the system starts, the /etc/init.d/pppd check if /etc/ppp/ppp_on_boot exists and in that case runs this file. The script just turn on the modem and calls pppd to connect to movistar.

= Troubleshooting =

Debug information can found in

 tail -f /var/log/messages

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