[Sugar-devel] TA with sensors

[Tomeu Vizoso]

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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