I quote Alexander E. Patrakov 2011-02-17:
> This may be because Nokia N900 eats the first character of the commands if they
are issued immediately after opening /dev/ttyACM0. Here is how to demonstrate
the bug without modemmanager:
>
> chat -V "" +++AT OK </dev/ttyACM0 >/dev/ttyACM0
>
> Try this command several times. Many times you will have only two plusses out
of three echoed back.
At the gentoo bug forums, this is discussed too: http:// bugs.gentoo. org/show_ bug.cgi? id=348849
I quote Alexander E. Patrakov 2011-02-17:
> This may be because Nokia N900 eats the first character of the commands if they
are issued immediately after opening /dev/ttyACM0. Here is how to demonstrate
the bug without modemmanager:
>
> chat -V "" +++AT OK </dev/ttyACM0 >/dev/ttyACM0
>
> Try this command several times. Many times you will have only two plusses out
of three echoed back.