/dev/ttyACM0 error

[STeve]

Hi

I installed MSPGCC 4 toolchain and mspdebug in order to work on my
Launchpad, as descibed in many websites, and everything is working
nicely.
However I can not open the USB port to read the temperatures from the
Launchpad demo code.
I did a lot of research on the net, I found that somebody else had the
problem but nobody actually posted a workaround.
Some people upgraded from a previous distro (for example from Ubuntu
8.04 to Ubuntu 10.04) to have the problem solved.
However I'm already using the latest Ubuntu version (10.04 LTS) and I
still have the problem.
mspdebug (mspdebug rf2500) is working perfectly, the port /dev/ttyACM0
is present every time the Launchpad is connected to the USB port, but
every time I try to access it :

$ sudo stty 2400 < /dev/ttyACM0
bash: /dev/ttyACM0: Input/output error

Any suggestion/hint about that ?
Any specific setting for the ACM0 port or the udev or something
else ?

Thanks
STeve

[Kevin Mark]

I have had issue with this too.
I put the temp demo in a loop (the python one) and after a while of
unplugging/plugging it in and pushing the button, the temp demo starts to work.
at that point, I can use the above command and do 'cat /dev/ttyACM0' and have
it output something.
I run the python script with sudo.

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[STeve]

On Sep 24, 9:51 pm, Kevin Mark <kevin.m...@verizon.net> wrote:

> I put the temp demo in a loop (the python one) and after a while of
> unplugging/plugging it in and pushing the button, the temp demo starts to work.

This approach seems not working with my system.
So far the error remains.

Thanks for the suggestion

C'ya
STeve

[Kevin Mark]

I noticed when I plug and unplug the launchpad unit on my XO-1.5, the device
changes (eg. /dev/ttyACM0, /dev/ttyACM1,..). I devised a solution that will
work to make it not change.

I added a UDEV rule to make a constant device name:
Create a file named '/etc/udev/rules.d/46-TI_launchpad.rules'
if should be root:root and 644
It should contain:
ATTRS{idVendor}=="0451" ATTRS{idProduct}=="f432" MODE="0660" GROUP="dialout" NAME="launchpad"

This will create /dev/launchpad for your one Launchpad device.
It is not to be used if you have 2 Launchpads attached.

So if you have a program that used '/dev/ttyACM0', then replace it with '/dev/launchpad'.

Let me know if this does not work on other linux distros.

[STeve]

Hi Kevin

On Oct 1, 12:20 am, Kevin Mark <kevin.m...@verizon.net> wrote:
> I noticed when I plug and unplug the launchpad unit on my XO-1.5, the device
> changes (eg. /dev/ttyACM0, /dev/ttyACM1,..). I devised a solution that will

In my case I already notice a different behavior.
Every time I plug int the board, I have always the dev/ttyACM0
Anyway I did a try, I created the udev rule as you suggested and so
far I just obtained that mspdebug is not recognizing anymore the
Launchpad :-(
I removed the udev rule and mspdebug "partially" restarted to work.
i.e. recognize the board, starts and then ends up in some internal
timeout when is trying to reset the chipset.

> This will create /dev/launchpad for your one Launchpad device.

It does create the launchpad device, but is not recognized by mspdebug
anymore.

I'm using Ubuntu 10.04 LTS Lucid Lynx.

C'ya
STeve

[Kevin Mark]

I found that it does create /dev/launchpad but it take like 1 minute for it to showup.
so I:
unplug the launchpad
plug the launchpad
and run this script:
----------------------------
while [ ! -e /dev/launchpad ]; do :; done
sudo /usr/bin/local/mspdebug RF2500
----------------------
and then it waits for the device node to appear before.
-K