minicom 2.3 putting garbage out to the kernel

Hi,

I’ve tried to adjust the environment variables in Debian to allow me to use minicom, i.e. LANG=C but either way I am getting garbage to the screen. Is this a known problem or a bug in minicom?

Is there another way to get output from my beagleboard? I have it connected through the DVI port but nothing shows up on the screen.

I have installed, or attempted to install software previously onto the bb, so I may have corrupted boot software. I do have an SD card with new boot software (MLO, etc) but that produces the same output.

TIA,

Jeremiah

If I assume that you have a Rev C4 ttypically garbage is one or two things. One you have the wrong cable configuration which in most cases it the wrong ribbon cable or you do not have a null modem cable.
If I assume you have a -xM, then a straight thru cable is required or a USB to serial adapter plugs right into the board

The second is the same in both cases, that you do not have the correct settings in minicom. You need 115K, 8, n 1.

Gerald

or as a friend of mine found out, if you have an xM, you really need
to have the SD card in there.

  don't laugh. if one is used to a C4, one might be used to powering
up the board without an SD card, just to test the serial connection
since, in that case, you'll at least see the u-boot info. but if you
carry that habit over to the xM, yes, you'll get garbage.

rday

That is a valid point! Except that the SD card is supposed to be in the conenctor when it ships.

Gerald

oh, i realize that. and, sheepishly, i'll admit that i made
*exactly* the mistake above when i got a prototype xM to play with
some time ago.

  i wanted to see the layout of the SD card so i popped it out,
slapped it into the laptop, was checking out the contents, then --
without thinking clearly -- connected and powered up the board, and
couldn't figure out why i was getting junk. i was still mentally in
C4 mode.

  so, at this point, that's the first question i would ask.

rday

Great idea! I think we also need to start having everyone indicate in the title the board revision just to set the right context.

Gerald

Great idea! I think we also need to start having everyone indicate in the title the board revision just to set the right context.

Fair enough. I am using the C4 version of the Beagle board. I have connected to the board with a Serial cable which works otherwise. The cable is then connected to another computer on which I run minicom.

I also log into the machine over ssh and then run minicom but either way I get unintelligible chars printed to the screen. There is an error that often comes which mentions UTF-8, but even when passing LANG=C environment variable the screen is still filled with crud.

I am now exploring putty to see if this well either confirm / deny that there are problems with minicom. Does anyone have a good command line incantation for putty to speak to a terminal?

Thanks!

Jeremiah

If I assume that you have a Rev C4 ttypically garbage is one or two
things. One you have the wrong cable configuration which in most
cases it the wrong ribbon cable or you do not have a null modem
cable.

If I assume you have a -xM, then a straight thru cable is required
or a USB to serial adapter plugs right into the board

or as a friend of mine found out, if you have an xM, you really need
to have the SD card in there.

Yep, I sure did :wink:

don’t laugh. if one is used to a C4, one might be used to powering
up the board without an SD card, just to test the serial connection
since, in that case, you’ll at least see the u-boot info. but if you
carry that habit over to the xM, yes, you’ll get garbage.

For the record, every other dev board I have worked with boots to a boot prompt without a card inserted. Not to say that this is right or wrong, but it’s why I had tried to initially test the board without a card inserted. Also, the card included with my XM was not inserted as shipped but rather was packaged with the board and I didn’t notice it in the box when I initially unpacked the board.

Is it safe to assume that you don’t read the manual either::^)

I think on the first batch of boards, the card was indeed in the box because we had already bagged the boards before we had the final software show up.

Gerald

Jeremiah - regarding the serial cable, make sure that it is null modem. Also, make sure that hardware and software flow control are turned OFF, as that will also create garbage on the line.

I have tried to use putty before but couldn’t get quite the right setup to make it talk to the serial port. Hyperterminal might work.

BTW have you gotten minicom to work on other boards, and are just having difficulty with the Beagle? If so, perhaps there is some setting left over from the other boards that is different from default. You could always remove .minirc.dfl and try again.

# putty -serial -sercfg 8,1,115200,n,N /dev/ttyS0

works.

I use gtkterm which is much simpler to build, install and run, no messing as with minicom - it's a GUI hyperterminal clone for Linux.
# ./configure
# make
# make install
# gtkterm &
Change the port if it's not the default /dev/ttyS0 and that's it. Save the configuration so it can be loaded next time or alter ~/.gtktermrc and change the default port - in my case /dev/ttyUSB1.
https://fedorahosted.org/released/gtkterm/
The latest is gtkterm-0.99.6.tar.gz dated 12-Sep-2010 16:42.
I had been using a version installed Oct-2007, but I just built the latest and am now using it with my C3 board.
Regards
Sid.

Jeremiah - regarding the serial cable, make sure that it is null modem. Also, make sure that hardware and software flow control are turned OFF, as that will also create garbage on the line.

Thanks Jeff, I’ll double check, but I’m pretty sure its a null-modem cable and I know I’ve turned off flow control. But no reason not to double check.

I have tried to use putty before but couldn’t get quite the right setup to make it talk to the serial port. Hyperterminal might work.

I’ll investigate Hyperterminal, thanks.

BTW have you gotten minicom to work on other boards, and are just having difficulty with the Beagle? If so, perhaps there is some setting left over from the other boards that is different from default. You could always remove .minirc.dfl and try again.

This is my first use of minicom.

Thanks again,

Jeremiah

Sweet. I’ll test on my machine. :slight_smile:

Jeremiah

I use gtkterm which is much simpler to build, install and run, no messing as with minicom - it’s a GUI hyperterminal clone for Linux.

./configure

make

make install

gtkterm &

Change the port if it’s not the default /dev/ttyS0 and that’s it.

Yeah, I have connected the serial cable to a USB port with a USB adapter. I know, one more thing to debug. :frowning:

Save the configuration so it can be loaded next time or alter ~/.gtktermrc and change the default port - in my case /dev/ttyUSB1.
https://fedorahosted.org/released/gtkterm/
The latest is gtkterm-0.99.6.tar.gz dated 12-Sep-2010 16:42.
I had been using a version installed Oct-2007, but I just built the latest and am now using it with my C3 board.

Cheers Sid, thanks a lot - I’ll test it out.

Jeremiah

It turns out that my serial cable was mis-wired. I re-soldered it and I got data I could read. :slight_smile: