Connect to /dev/ttyS1?

atziazas · 06-30-2009, 09:58 AM

Ok so to my understanding, /dev/ttyS1 is a serial port on my device and it is connected to a GSM modem (that is what the company claims).

So I want to be able to "converse" with that modem and send in some AT instructions.

I was told I could use "chat" or "screen" but I have tried everything in chat and I can't get it to talk to me. "screen" does not exist on Angstrom and since I do not have an internet connection on the device, I don't know how to get it on there.

Any ideas?

Here's an example of what I did:

chat -v -s '' 'AT#BND?' 'OK' /dev/ttyS1
send (AT#BND?^M)
expect (OK) AT#BND?
alarm
Failed

I also tried without the 'OK' part.

Not quite sure what to do.

Thanks

David1357 · 06-30-2009, 12:13 PM

Quote:

Originally Posted by atziazas

Not quite sure what to do.

Have you tried opening a minicom session and typing the desired commands from there? You can use minicom to debug your chat script.

WvDial is also very handy. It can auto-detect a lot of modem settings.

atziazas · 06-30-2009, 01:00 PM

My distribution of Angstrom did not come with minicom and it is running on a single board computer.

I also don't have the "make" command on my linux.

Any ideas?

David1357 · 06-30-2009, 04:45 PM

Quote:

Originally Posted by atziazas

Any ideas?

When I had a similar problem, I got everything working on a desktop Linux machine using WvDial. When everything was working, I looked at the options and commands WvDial was using and then wrote chat scripts to do the same thing. I trimmed lines from the chat scripts until I had the minimal script needed to get the modem working. Then I moved those scripts to the target and everything worked.

Your other option is to install Ubuntu on the single board computer (SBC). If you just install Linux without the GUI (GNOME), it might fit.

atziazas · 07-01-2009, 09:29 AM

I am using my Mac and Kermit. I can connect to the device but I don't know how to make kermit connect directly to ttyS1 instead of wherever it currently connects.

David1357 · 07-06-2009, 08:56 AM

Quote:

Originally Posted by atziazas

I can connect to the device but I don't know how to make kermit connect directly to ttyS1 instead of wherever it currently connects.

I am assuming you have the modem connected to your Mac.

Here is the option to tell Kermit which serial port to use:

Code:

-l arg 	N 	(Lowercase letter L) Make a connection on the given
                serial communications device. Equivalent to the SET
                LINE (SET PORT) command.
                Argument: Serial device name, e.g. /dev/ttyS0.

This is from the Kermit tutorial and man page.