[LAU] Raspberry: problems with shell script launcher when booting

[Carlos sanchiavedraz]

Hi Jeremy,

2013/7/15 Jeremy Jongepier <jeremy at autostatic.com>:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> On 07/15/2013 02:23 PM, Carlos sanchiavedraz wrote:
>> Hi Jeremy,
>>
>
> [...]
>
>>> Hi Carlos,
>>>
>>> Try resetting the JACK buffersize with jack_bufsize after
>>> starting your program. This does the trick for me on the RPi.
>>
>> It seems it did my trick as well, great! For the moment sound seems
>> to be as clean as it can until the moment I debug other inner
>> noises (it sounds like that of physical hard drives turning, but
>> there's none in RPi (?)) when nothing is plugged in the audio
>> interface.
>>
>
> What kind of audio interface are you using? You might have to ground
> it properly (assunimg you're using an USB interface):
> http://sourceforge.net/apps/mediawiki/guitarix/index.php?title=Guitarix_Embedded_/_ARM_SoC#Fighting_the_Noise
>

What I supposed is exactly what it points in that article:
"noise on the USB power line will feed into the preamplifier of the
audio interface",

or maybe not, but it is probably. But cutting cables and soldering I'm
afraid it's not an option for now; don't want to change my audio
interface into some Frankenterface and break it.
I'll see if I can clean a little bit more without going extremes.

> [...]
>
>>
>> Now, there's just a minimum issue, but I can live with it.
>> Rackarrack runs now as "pi" user and it should take its
>> configuration from user's $HOME, that is what it should be
>> "/home/pi", but it seems that it doesn't. The difference between
>> running the launcher script when logged in as pi is that it takes
>> the MIDI mapping configured in preferences, but when launched
>> automatically on init phase it takes the default MIDI mapping.
>>
>> I run the launcher script from the service script with: su -l -c
>> $STARTPATH/launcherscript.sh pi
>>
>> ...and "-l" should load the pi environment (I checked it when
>> debugging). Maybe is something specific with Rakarrack.
>>
>> Thanks so much, Jeremy.
>>
>
> I'm using 'su -l pi -c /some/command' myself but the order shouldn't
> matter I guess. Otherwise you could take a look at start-stop-daemon.
> Examples can be found in /etc/init.d/skeleton
>
> Jeremy

My service script is based on Debian norms:
http://wiki.debian.org/LSBInitScripts

Basically:
* First the config for Run-time dependencies in the format indicated
* Shell methods for start, stop...

On my method start is that command I mentioned:
su -l -c
>> $STARTPATH/launcherscript.sh pi

I've seen that other service run whichever command but preceded by
start-stop-daemon -v, but I'm not sure it makes a difference for this
issue. And since this is not a proper "service" but a launcher at the
very beginning, I didn't use start-stop-daemon.

Thanks again.


-- 
Carlos sanchiavedraz
* Musix GNU+Linux
  http://www.musix.es