[OLPC library] Get involved - Measure Activity on the XO (Edward Cherlin)

[Arjun Sarwal]

All that would be needed is a
thermistor
2 wires
1 3.5mm audio connector

Use either Measure, or write your own app using the Measure audio-grabbing class
For example TurtleArtwithSensors Activity uses the Measure audiograb
class and it is as simple as
set_sensor_type ()    (there are basically just 2 types, resistive
and voltage type)
get_sensor_value()

and you have the sensor values.


you can, depending upon the characteristics of the sensor, callibrate
the values to give a direct readout of temperature.

Im working on a text box in Measure which would give a more clear
indication of actual values along with the waveform displayed. The
values are perhaps of much more significance in the case of DC
voltages obtained from sensors.

The simplicity of Measure is in the fact that one is connecting the
sensors to the Mic-in jack, as opposed to the USB. The software part
is also thus more transparent and simpler...


Im also working on a revamping of the old measure wiki page
(http://wiki.laptop.org/go/Measure) and work in progress is here
http://wiki.laptop.org/go/Measure/New_temp

Suggestions, feedback, contributions most welcome!


regards
Arjun


On Thu, Apr 10, 2008 at 11:02 PM, John <johnstout at aol.com> wrote:
> Students at Colorado School of Mines cobbled together a thermister to gather
> temperature data for their LEGO computer. I suppose all that would be needed
> when Measure is interfaced with USB, is a connector for Measure to do
> calibrations on the XO?
>
>  Sent from John's iPhone
>
>
>
>  On Apr 10, 2008, at 10:51, "Arjun Sarwal" <arjun at laptop.org> wrote:
>
>
> >
> >
> >
> > On Thu, Apr 10, 2008 at 10:11 PM, Langellier, Larry
> > <Langellier at morainevalley.edu> wrote:
> >
> > > Ed's post reminded me to ask a question I've been wondering about:
> > >
> > >
> > > > I wrote a report some years ago under the title Personal Instruments,
> > > > talking about digital oscilliscope boards for PCs, inexpensive
> > > > instruments, and data visualization and analysis software.
> > > >
> > >
> > > Has anyone tried to hook up a Scratch Board
> (http://scratch.wik.is/Support/Scratch_Board) for use with Measure? Can
> Measure be modified to get input from a USB port?
> > >
> >
> > The scratch board is great. However Measure allows one to do the same
> > things by plugging in sensors costing about $1 or $2, while the
> > scratch board costs $25.
> >
> > Measure, currently has no support for USB interfacing, but I'm sure it
> > can be done.
> >
> > Edward Baafi of the Fablab has made a $2 sensor board that plugs into
> > the USB and is installed like a USB-keyboard and continuously sends
> > sensor values from the values sampled off the 3 ADC channels of the
> > AtTiny micro controller that he's used.
> >
> >
> > Any suggestions for Measure and sensors are most welcome.
> >
> >
> > kind regards
> > Arjun
> >
> > _______________________________________________
> > Library mailing list
> > Library at lists.laptop.org
> > http://lists.laptop.org/listinfo/library
> >
>



-- 
Arjun Sarwal
Intern, One Laptop per Child
Email: arjun at laptop.org
IRC: arjs on irc.freenode.net in #olpc, #olpc-health, #sugar
Skype: arjunsarwal85