[Sugar-devel] TA with sensors

[Walter Bender]

Thanks. I'll give it a try.

-walter

On Sat, Jan 3, 2009 at 4:48 AM, Tomeu Vizoso <tomeu at sugarlabs.org> wrote:
> Also, see the link below for a way to detect when the activity window
> is visible or not:
>
> http://git.sugarlabs.org/projects/sugar/repos/mainline/blobs/master/src/jarabe/journal/journalactivity.py#line298
>
> It's used by the journal in order to decide whether it needs to auto
> refresh its view or not.
>
> Regards,
>
> Tomeu
>
> On Sat, Jan 3, 2009 at 05:19, Arjun Sarwal <arjun at laptop.org> wrote:
>> On Sat, Jan 3, 2009 at 1:18 AM, Walter Bender <walter.bender at gmail.com> wrote:
>>> Thanks for this background.
>>>
>>> I think that the try/exception mechanism is adequate for our needs. It
>>> will be otherwise trivial for me to add the sensor features to the
>>> main branch of TA... I'll add it to the next release.
>>>
>>> I wonder if there is a mechanism we can call upon (Sugar should
>>> perhaps provide this) that will tell us that we are being sent to the
>>> background so that we can only reinitialize when we go away and come
>>> back? It seems that for every call to the sensor, it is a large
>>> overhead to incur...
>>>
>>
>> There are signals in Sugar that are fired when an Activity becomes the
>> background Activity or foreground Activity (I've used these in Measure
>> code). It seems like a good idea to explore to keep the capture device
>> ON while TurtleArt is the active Activity and leave the audio device
>> when Activity is in background and then  re-initialize it when
>> TurtleArt becomes the active Activity.
>>
>>> -walter
>>>
>>> On Fri, Jan 2, 2009 at 2:25 PM, Arjun Sarwal <arjunsarwal at gmail.com> wrote:
>>>> Hello Walter,
>>>>
>>>> Thank you for the new year wishes. Best wishes to you too for the new
>>>> year! (hope you received my card too)
>>>>
>>>> A few points regarding adding sensor support
>>>>
>>>> * Calls to Alsamixer to set the DC mode on/off will result in an
>>>> exception on one's normal laptop. This is because the DC mode controls
>>>> don't exist in the Alsamixer of a normal laptop (even sugar emulation
>>>> makes calls to the laptop's default alsamixer)
>>>>
>>>> * I had put in initializations before each call to the sensor because
>>>>  - user may switch to another Activity  in between a session of Turtle
>>>> Art -- the other Activity  may use the laptop's sound device. The
>>>> other Activity may alter the sound device settings.
>>>>  - unless a call for sensor input is being made, I didn't want to keep
>>>> the capture device active.
>>>> The capture device can be thought to be in a state of 'recording
>>>> sound' when one is getting sensor input data, hence only one
>>>> Activity/program can have access to it at one time.
>>>> However, any suggestions you may have on the above implementation
>>>> would be very welcome.
>>>>
>>>>
>>>> * If it helps, I am summarizing approximately the changes  I made in
>>>> TurtleArt to add sensor support and some relevant lines to look at
>>>> within the TA with Sensors code that I had made for the earlier (non
>>>> SVG version of TAwithSensors):
>>>> Referring to the  version of the online git tree ('Initial import')
>>>> (http://dev.laptop.org/git?p=users/arjs/TurtleArtwithSensors;a=tree;h=3f22f9f86d60f6160268c52009273eba82dba465;hb=3f22f9f86d60f6160268c52009273eba82dba465)
>>>>
>>>> - audiograb.py as an additional file was included completely
>>>> - talogo.py :
>>>> (note that lines 8 and 9 in this version of git tree would need to be
>>>> changed to
>>>> from numpy.oldnumeric import *
>>>> from numpy.fft import *  )
>>>> lines 8,9,11,12 were added
>>>> lines 366 onwards till the end have been added
>>>> -tasetup.py: lines 47 to 51 to account for the additional sensor
>>>> blocks in the UI
>>>>
>>>> As you can see from the code of talogo.py , the approach involves a
>>>> lot of painful starting the whole gstreamer pipeline, getting one
>>>> sample then stopping the pipeline. An overkill for getting just one
>>>> sample, but there is no way unless python alsa audio is included in
>>>> the build system. The approach with python alsa audio is work in
>>>> progress here (
>>>> http://dev.laptop.org/git?p=users/arjs/TurtleArtwithSensors;a=tree )
>>>>
>>>> I want to work on incorporating sensor support into the SVG version of
>>>> TA that you have made, but my current day job isn't leaving me any
>>>> time these days to do anything else. I will get to it as soon as I get
>>>> the opportunity, but if in the meanwhile you get a chance to do it -
>>>> it'd be great.
>>>>
>>>> Please let me know if I can help further.
>>>>
>>>> Kind Regards
>>>> Arjun
>>>>
>>>> On Fri, Jan 2, 2009 at 3:18 AM, Walter Bender <walter.bender at gmail.com> wrote:
>>>>>
>>>>> I've begun folding TA with sensors into TA. I use an exception to
>>>>> catch the calls to set DC Mode in Alsamixer, so it seems to run fine
>>>>> on my normal laptop using the mic input. But when I look at the logs,
>>>>> it seems that there is a lot of initialization that happens with every
>>>>> call to the sensor. Is that all necessary? Can we just check for
>>>>> changes after the first time?
>>>>>
>>>>> -walter
>>>>>
>>>>>
>>>>>
>>>>>        # test to see if DC Mode is enabled
>>>>>        try:
>>>>>            self.dcmode = Mixer('DC Mode Enable')
>>>>>            self.bias = Mixer('V_REFOUT Enable')
>>>>>            self.has_dcmode = True
>>>>>        except:
>>>>>            print "DC Mode unavailable"
>>>>>            self.has_dcmode = False
>>>>>
>>>>>
>>>>>
>>>>> Walter Bender
>>>>> Sugar Labs
>>>>> http://www.sugarlabs.org
>>>>
>>>>
>>>>
>>>> --
>>>> Arjun Sarwal
>>>>
>>>
>>>
>>>
>>> --
>>> Walter Bender
>>> Sugar Labs
>>> http://www.sugarlabs.org
>>>
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>



-- 
Walter Bender
Sugar Labs
http://www.sugarlabs.org