PHARscape

Nagalaxmi · Joined: 25 Jan 2006 Posts: 2

Hello,

I am using "GlobeTrotter Universal Tri-band GPRS/GSM PC-Radio Card (WK version)", which is connected to Linux based Laptop. I started testing it according to "Option Globetrotter(GPRS) Howto".

After inserting the card i can hear two high pitched beeps. The command "dmesg" shows me "ttyS3 at port 0x02e8 (irq = 3) is a 16550A" near the last line. Stab file checking command "more /var/lib/pcmcia/stab" shows me
"Socket 0: Serial or Modem
0 serial serial_cs 0 ttyS3 4 67"
and command "ls -l /dev/modem" shows me "lrwxrwxrwx 1 root root 10 Jan 25 12:41 /dev/modem -> /dev/ttyS3"
After checking these i thought i can communicate with modem using AT commands. First, i want to send and receive SMS.

so, i started Minicom in configuration mode with the command "minicom -o -s", my serial port setup is as below,
A - Serial Device: /dev/ttyS3
B - Lockfile Location: /var/lock
C - Callin Program:
D - Callout Program:
E - Bps/Par/Bits: 38400 8N1
F - Hardware Flow Control: Yes
G - Software Flow Control: No

Configuration is saved as "gsm" and exited from Minicom.

Now, i want to send and receive SMS. so, i opened Minicom with "minicom -o gsm" . i entered AT, as soon as i enter AT i am getting "?." (i think i am supposed to get "OK") i can not see text "AT" also and further if i enter AT i get "???." and so on, i can not see any text that i enter or any proper response, i can see only question marks with dot.

Please let me know whether whatever i have followed till now is correct or not? Please Let me know how can i resolve this? My basic requirement is to send and receive SMS.

I used same card with Windows XP, with Windows Globetrotter device drivers and the Globetrotter Mobility Manager installed. I am able to communicate through Hyper Terminal, all commands like AT+CMGR, AT+CMGS works fine and i am able to send and receive SMS properly. Now i want to do same on Linux, please guide me how can i proceed further.

Thanks for your time.

Thanks and Regards,
Nagalaxmi B V

Paul · Posted: Wed Jan 25, 2006 10:32 am Post subject:

Hi Nagalaxmi B V, welcome to the Forum,

The the WK will only operate at 115200 baud. Please try the connection again at this speed.

Have fun,
Paul

Nagalaxmi · Joined: 25 Jan 2006 Posts: 2

Hello Paul,

Thanks a lot, it is working.....

Regards,
Nagalaxmi B V

sandeep · Joined: 11 Mar 2006 Posts: 7

I've got an embedded target board with linux running on it. and which is connected to gprs modem via serial link. I need to send some data to our server through that modem.
I have written the scripts for ppp serial link but it is not getting connected and showing "LCP terminated by peer'.
I have following files :
/etc/ppp/peers/gprs:
-----------------------
/dev/ttyS1
defaultroute
usepeerdns
nodetach
noauth
debug
connect "/usr/sbin/chat -v -f /etc/ppp/gprs-connect"
diconnect "/usr/sbin/chat -v -f /etc/ppp/gprs-disconect"

/etc/ppp/gprs-connect:
---------------------------
TIMEOUT 10
ABORT 'BUSY'
ABORT 'NO ANSWER'
"" 'ATZ'
OK 'ATE0V1'
OK 'AT+CGCONT=1,"IP","www"'
ABORT 'NO CALLING'
OK 'ATD*9***1#'
CONNECT ''

Can anybosy please help me?

Paul · Posted: Sun Mar 12, 2006 8:39 pm Post subject:

Hi,

Try:

novj

Paul Wink

sandeep · Joined: 11 Mar 2006 Posts: 7

Now I hve landed up in different error:
starting gprs connect script
reseting the modem
setting apn
Serial connection established.
using channel 2
Using interface ppp0
Connect: ppp0 /dev/rmodem
Warning - secret file /etc/ppp/pap-secrets has world and/or group access
sent [LCP ConfReq id=0x1 ]
rcvd [LCP ConfReq id=0x1 ]
sent [LCP ConfAck id=0x1 ]
rcvd [LCP ConfAck id=0x1 ]
sent [IPCP ConfReq id=0x1 ]
sent [CCP ConfReq id=0x1 ]
rcvd [IPCP ConfReq id=0x1 ]
sent [IPCP ConfRej id=0x1 ]
rcvd [CCP ConfReq id=0x1 ]
sent [CCP ConfAck id=0x1 ]
rcvd [IPCP ConfRej id=0x1 ]
sent [IPCP ConfReq id=0x2 ]
rcvd [CCP ConfAck id=0x1 ]
Deflate (15) compression enabled
rcvd [IPCP ConfReq id=0x2 ]
sent [IPCP ConfRej id=0x2 ]
rcvd [IPCP ConfRej id=0x2 ]
sent [IPCP ConfReq id=0x3]
rcvd [IPCP ConfReq id=0x3]
sent [IPCP ConfAck id=0x3]
rcvd [IPCP ConfAck id=0x3]
Could not determine local IP address
sent [IPCP TermReq id=0x4 "Could not determine local IP address"]
sent [IPCP TermReq id=0x5 "Could not determine local IP address"]
sent [LCP TermReq id=0x2 "No network protocols running"]
rcvd [LCP TermReq id=0x2 "No network protocols running"]
sent [LCP TermAck id=0x2]
rcvd [LCP TermAck id=0x2]
Connection terminated.
Connect time 0.1 minutes.
Sent 110 bytes, received 110 bytes.
Serial link disconnected.

I also tried using AT# commands but modem is not supporting them. It looks like modem doesn't have tcp/ip stack. and if we assume that pxa255 conroller have tcp/ip stack then how do I establish the gprs connectivity?

Paul · Posted: Fri Mar 17, 2006 12:37 pm Post subject:

These are the PPD options I use:

#############
novj
replacedefaultroute
defaultroute
nobsdcomp
debug
usepeerdns
noipdefault
#############

What options are required will depend on how modern you pppd is.

I would recommend disabling any compression scheme so also try:
############
noccp
nodeflate
############
if they are supported by your version of pppd.

All of these datacards provide a ppp peer.

When debugging these problems it is a good idea to try the same datacard and SIM on another OS (like Windows Evil or Very Mad

) just to prove your data account is active and that all the elements are working.

What do you mean AT# commands? The AT commands supported by this datacard are detailed in the 3GPP specifications and in the documentation available on Option's website. You cannot expect Option to implement another manufacturers proprietary commands.

Paul

sandeep · Joined: 11 Mar 2006 Posts: 7

I tried all the options you said but the same above error.
what does it mean when it says "could not determine local ip address" ?and "no netwok protocols running"? Is it because I don't have any eth0 on my Linux board?

Paul · Posted: Mon Mar 20, 2006 9:17 am Post subject:

Hi Sandeep,

For some reason the computer has not been suppled with an IP address by it's peer (The GPRS network) and consequently there is no TCP/IP type traffic on the port.

This could be because of poor signal strength or even an incorrect APN for the SIM you are using. It is also possible that the network advertises GPRS is available but cannot actually deliver the service.

Have you confirmed that the card is registered and has good signal strength before you try to connect?

Have you confirmed that the APN is correct and that you can connect using an alternative OS?

Paul

sandeep · Joined: 11 Mar 2006 Posts: 7

Hi Paul,
How to check if the SIM is registered and has good signal strength?
and APN is correct as I have confirmed it many times from the operator,though I didn't use it on different OS.

sandeep · Joined: 11 Mar 2006 Posts: 7

Hi Paul,
I'm using wavecom wismo GPRS Modem. I have confirmed it with one of the dealers that the Modem I'm using doesn't have the Network layer.
Now in this case how do I transfer my data through the modem.?
I have an ARM based pxa255 board having Linux on it. and on the same board I have GPRS Modem. I have to write a program in C which will read some data from a file and will transfer the data to our server every 1 min. after TCP/IP connection is established. Now I don't have tcp/ip stack in modem.Then will I do it? If I use socket programming to transfer and receive the data, which protocol do i need to use,TCP or UDP?
Please do help.

Thanks,
Sandeep.

Paul · Posted: Mon Mar 20, 2006 9:37 pm Post subject:

I know about Option datacards - I do not know about your Wavecom wismo Modem!

In general....
The normal solution is to run a ppp connection between the host computer and the modem (the modem is the ppp peer). The modem translates the GPRS signalling into a ppp session that the laptop or pxa255 understands.

This requires that your pxa255 is running pppd. If the wismo supports modem emulation mode you can start the ppp session with the AT dial command ATD*99#

If your wismo GPRS modem does not support modem emulation and ppp then contact your supplier for technical information on what data interface it does supply.

Paul

sandeep · Joined: 11 Mar 2006 Posts: 7

Hi,
I'm getting the ppp0 link up. Now using AT(AT#) commands for TCP/IP, I'll be sending the tcp packets to the server.
Now if I want to use my same Linux system as server, then how will I receive those packets? What needs to be done on the server inorder to receive those packets?

Paul · Posted: Fri Mar 31, 2006 8:32 am Post subject:

Hi Sandeep,

On a lot of networks you cannot have a network originated data connection - the card must make the connection (it must dial *99# etc). This means you either have some sort of ring-back facility or your Linux box is connected to the internet all the time.

To do ring-back some program will monitor the serial connection for incomming call requests or an SMS and then the box will dial out as normal to connect to the internet.

The problem is that you need a public IP address (or a static private address with network routing in the operators network to your box) for your linux box to be visible on the Internet. You need to ask your network operator about this.

Paul

sandeep · Joined: 11 Mar 2006 Posts: 7

Paul,
I've got a new SIMCOM GPRS modem. Following is the sceenshot at the client PC in hyperterminal/Minicom:
at+cgdcont=1,"IP","APN"
OK
at+ciicr
OK
at+cifsr
OK
at+cipstart="tcp","remote server ip address","port no"
OK
CONNECT OK
at+cipsend
>I'm sending this data from the client
SEND OK

This is demo showed by Modem provider. He first ran the server.exe on the server which had external ip. After ruuning that exe a GUI appears which will have its ip address and tcp port on one side and a window where u can type some text to send to the client, also one more window for the data that is received from the client.

Now see this server program must be socket program. I have few questions:
1.Does this at+cipstart opens the tcp socket like we do in our socket program using socket command?
2.after issuing at+cipsend I get a promt '>' where I can type text and then I need to press ctrl+z which will send this data to the server. How do I write these sequence of commands in a file or a scipt in Linux?

Please do respond ASAP. Thanks

Sandeep.