RevC4 - can NOT get Serial Console access! Never able to. Help!!??

Hello!
I have a RevC4 (only purchased it 3 weeks ago) and only used it a few
times (No use without serial).

I CAN NOT GET ACCESS TO SERIAL CONSOLE!
I have never been able to gain serial access.

I have tried 4 computers:
MacBook White (c2d)
MacBook Pro ('10 - c2d)
eeePC Running Mint Linux.
Desktop with Vista.

What OS's have I tried?

OSX 10.6
Mint Linux 8, 9 & 10 and Ubuntu
Windows: XP & Vista

I have the correct hardware.
I went out yesterday and got a new usb-serial cable, just to alleviate
hardware issues ($30! Rip off) but it works fine (cable).

I have the bulkhead-serial (from Special computing) with red strip on
pin 1 (in clear case), Null Modem cable and usb-serial.

Windows Vista popped up and said "Omap 3450" no drivers found. So
windows CAN see it, but no serial.
I have tried:

Hyper Term
Tera Term
PuTTy
Minicom (linux)
Minicom (osx)
Screen (osx)

I have the correct drivers in Windows and OSX. (PL2303 I think they
are).
Also have drivers on the mini-cd which came with cable.

This has stressed me out so ******* much!

I have 0xDroid installed to NAND (happy installer) - I had no serial
access before this either(!!!!) and I have Angstrom booting from SD
card when installed.
I have done the above without console access.. But I want console
(thus why I purchased this) :frowning:

When I boot up a program (any of the above) it sits on a black screen
and does nothing.
I have left it for... up to 1 hour previously.

I am thinking this is a hardware fault.
I have followed all instructions.

This is making so bloody angry!

Please help!

Hello!
I have a RevC4 (only purchased it 3 weeks ago) and only used it a few
times (No use without serial).

I CAN NOT GET ACCESS TO SERIAL CONSOLE!
I have never been able to gain serial access.
...
This has stressed me out so ******* much!

The problem might be that RS-232 is a real bummer. The specification
only specifies signal levels in large ranges (logical 0=+3 to +12V,
1=-3V to -12V). Of course, generating negative voltages is hard and
therefore a large portion of modern hardware justs uses ground as
logical 1. Moreover, many implementations differ in what voltages
they'll actually accept. The whole "standard" is a bit of a mess. My
laptop's serial port is useless for communicating with half of the
instruments in my lab (although works with the BeagleBoard).

If you had a multimeter (or better an oscilloscope) you might be well
advised to check your signal levels.

I have 0xDroid installed to NAND (happy installer) - I had no serial
access before this either(!!!!) and I have Angstrom booting from SD
card when installed.
I have done the above without console access.. But I want console
(thus why I purchased this) :frowning:

When I boot up a program (any of the above) it sits on a black screen
and does nothing.
I have left it for... up to 1 hour previously.

Are you sure getty is running on the serial tty? Check inittab to ensure
that getty is configured to run on ttyS2 (it should be by default).

Also, which kernel version are you using? If you are running 2.6.37 or
newer the name of the exposed serial port has changed from ttyS2 to
ttyO2 (O for omap).

- Ben

I suggest you read the section 13 of the System Reference Manual and make sure you have the correct serial cable and the correct ribbon cable. In most cases , this is the issue.

http://beagle.s3.amazonaws.com/design/Beagle_SRM_C4_0_0.pdf

Also make sure you have the correct settings on you terminal program , in particular, no hardware handshaking.

Gerald

Hello Gerald,
I have been through Section 13 previously.
The only thing that I can see that could be wrong is my NULL modem...
I can't see how?

Upon looking at this: http://digital.ni.com/public.nsf/allkb/1EE0DD8AF67922FA86256F720071DECF

I think that I would need a "simple" version ONLY?
If I have the one with "handshaking" should I open it up and cut the
rest of the lines and just leave TX, RX & RND intact?

This seems like the possible problem?

I do not know if I have the "handshake" or "simple". I will chop and
see if you guy's think that this cable version COULD be the problem.

Hello Ben,

Are you sure getty is running on the serial tty? Check inittab to ensure
that getty is configured to run on ttyS2 (it should be by default).

Also, which kernel version are you using? If you are running 2.6.37 or
newer the name of the exposed serial port has changed from ttyS2 to
ttyO2 (O for omap).

This is odd, I do not have access to serial on PC as you know.
I have not modified a thing on the BB. All I have done is booted
0xDroid, clicked the mouse (realised it has no MarketPlace and stopped
using it), Booted Angstrom Demo (01.2011), click a few buttons to test
and lastnight got Ubuntu 10.10 to boot and did not even log in.
I have not used this device. Nothing has been played or even typed :frowning:

This is the cable I have:

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=390224475576

Ditto that, and especially the section that shows how to disconnect
the cable from the BeagleBoard end and short out positions 2 & 3 to
make sure your terminal program can wrap data back to itself. That'll
test almost all parts but the BeagleBoard itself.

- Kerry

Ok.
I tried a few things.
Nothing has worked.
POS!
I tried the loopback and the best thing I got was: (minicom) could not
find a PTY.

I chopped my NULL modem in half. Wired ONLY 2, 3 and 5 (crossed 2 and
3). So it was 3 wires only. Failed again.

Yes, I have set minicom to 115200, 8 bit, no parity, 1bit and NO flow
control.
I am not new to the OMAP scene. I have an N900, hacked up nice and
fun.
I helped develop NITDroid, helped with many, many project (ubuntu/arch/
fedora on N900).

I am not new to terminal or kernels. But this should NOT be this
hard :frowning:

I don't want to spend anymore on this. I am unahppy with the BB at
this point :frowning:
I think I will buy a Null Modem from special computing, this should be
the right one?
https://specialcomp.com/beagleboard/order.htm
or this one from DigiKey.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=BBC01-ND

It is a bulkhead, going to female serial. This one seems much
different.

Hello Ben,

Hello.

>Are you sure getty is running on the serial tty? Check inittab to ensure
>that getty is configured to run on ttyS2 (it should be by default).

>Also, which kernel version are you using? If you are running 2.6.37 or
>newer the name of the exposed serial port has changed from ttyS2 to
>ttyO2 (O for omap).

This is odd, I do not have access to serial on PC as you know.

What is odd? I'm not sure I follow. To clarify, I was referring to the
kernel running on the Beagleboard.

I have not modified a thing on the BB. All I have done is booted
0xDroid, clicked the mouse (realised it has no MarketPlace and stopped
using it), Booted Angstrom Demo (01.2011), click a few buttons to test
and lastnight got Ubuntu 10.10 to boot and did not even log in.
I have not used this device. Nothing has been played or even typed :frowning:

I don't use 0xDroid and have no idea what it's default configuration
looks like. In both 0xDroid and Ubuntu, however, it seems quite likely
that getty isn't run on serial consoles by default.

- Ben

I do not know what getty is.
I am running Angstrom from SD card (with angstrom kernel).
Should this run fine, shouldn't it?

I have no seen anywhere that a configuration is needed when running
Angstrom.

Also,
Oddly enough, maybe this is normal: I do not need MLO or uboot files
on SD to boot OS's.
I boot Angstrom with only uImage on partition 1.
Ubuntu: Would not boot, so I removed all files and just left the
uImage, and it booted.
Is this normal for a RevC4??

I have decided that I should get a new set of cables, just to
alleviate all problems!
I am going to get a null modem and usb-serial from special computing
and possibly (just to make sure!) another IDC10 to DB9M bulkhead...
I need this serial working.

Could someone please help with what settings could be wrong on the BB
side?
getty - ?
I do not know how to change serial settings, unless these can be done
in Angstrom (boot from SD).
I thought this device was meant to have a constant serial connection
(hardware). So settings should not change this?

After fiddling around, Installed Ubuntu 10.10 in VMware. No luck
still. BUT!
Twice I got about 6 characters of garbage! Just question mark'ish
icons.. Garbage. But only twice and about 6 characters (instant, not
ongoing).

I think a new cable could help?
I will try. I tried to use beagleboard recovery tar.bz2 but that does
not work.

I have decided that I should get a new set of cables, just to
alleviate all problems!
I am going to get a null modem and usb-serial from special computing
and possibly (just to make sure!) another IDC10 to DB9M bulkhead...
I need this serial working.

Again, a better option would be to check over your setup with a
multimeter. Verify signal levels and check continuity of all cables.

Could someone please help with what settings could be wrong on the BB
side?
getty - ?

Getty is the process that presents you with a login prompt. If I recall
correctly, Ubuntu does not run getty on serial terminals by default.
I believe Angstrom does. You should check in /etc/inittab on the
Beagleboard and veryify there is a line referring to /dev/ttyS2.

Again ensure you aren't using flow control on the host side.

I do not know how to change serial settings, unless these can be done
in Angstrom (boot from SD).
I thought this device was meant to have a constant serial connection
(hardware). So settings should not change this?

Not sure what you mean by this. The device doesn't need a serial
connection. In my case, I only use the serial interface during board
bring-up. After that I simply use ssh, which is much more convenient and
far faster.

- Ben

I can not even get the default OMAP/xloader/uboot prompt.
How are we supposed to change options before you boot an os?
I don't care too much about serial access to angstrom or any other os.

I want OMAP/xloader serial console.

So I can do items like 'nand erase' and chose to boot from SD and
such..

Mainly after nand erase.