Measure/New temp: Difference between revisions

From OLPC
Jump to navigation Jump to search
No edit summary
No edit summary
Line 1: Line 1:
'''Page used for re-organizing Measure page w/o disturbing the main page till the re-organization is done'''
'''Page used for re-organizing Measure page w/o disturbing the main page till the re-organization is done'''


{{Olpcboxtop|toptext=[[{{PAGENAME}}|Measure]]}}
{{ OBX activity |[[Image:Activity-measure.svg]]|bundled<!--|{{{text}}}--> }}
{{ OBX source dev|projects/measure}}
{{ OBX test |[[Tests/Measure|Measure]]<!--|2007-09-18--> }}
{{ OBX devtickets |measure-activity}}
{{ OBX pootle|1=http://dev.laptop.org/git?p=projects/measure;a=blob_plain;f=po/Measure.pot;hb=HEAD|2=xobundled}}
{{ OBX xobundle|http://dev.laptop.org/~arjs/Measure-15.xo|measure v14}}
{{ OBX team |Adviser: [[User:Walter|Walter]], Core Development: [[User:arjs|Arjun]], Contributor(s): Cody Lodrige (drawing code optimization), Eben Eliason(UI Design)}}
<small>see more [[:Category:OBX templates|templates]] or [[OBX proposals|propose new]]</small>
{{Olpcboxbottom}}


{{OLPC}}
{{ Translations }}
__NOTOC__
__NOTOC__


<!-- -------beginning of top box row----- -->
<!-- -------beginning of top box row----- -->
{|style="border-spacing:8px;margin:0px -8px"
{|style="border-spacing:8px;margin:0px -8px"
|class="MainPageBG" style="width:45%; border:1px solid #aaaaaa; background-color:#fff; vertical-align:top; color:#000"|
|class="MainPageBG" style="width:45%; border:2px solid #aaaaaa; background-color:#fff; vertical-align:top; color:#000"|
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top; background-color:#fff"
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top; background-color:#fff"


Line 170: Line 156:


[[Category:OLPC]]
[[Category:OLPC]]



= What is the Measure Activity ? (Introduction) =

{|
|-
|[[image:Measure_1.png|thumb|300px|Measure Activity on the XO]]
|[[image:Measure_tut_1_24.jpg|thumb|300px|Analog Input port on the XO (in pink)]]
|}

The Measure Activity is a tool on the XO that allows kids to indulge in "learning by doing". It provides an interface for the kids to connect with the physical world and an opportunity to view and understand through a visual and statistical representation of the physical phenomena.

Using the Measure Activity on the XO, one can:

* Connect sensors (light, heat, magnetic field etc) and view their signal. Thus it is possible to view and study physical phenomena
* Input voltages and signals into the XO laptop and use it as an oscilloscope and
* Log data at a specified interval and store and retrieve waveforms

=Learning Activities =
==Introduction==
Children learn by doing things. It is said "Give a child a hammer, and the world becomes his nails".
This activity is a tool that allows kids to express their curiosity. It is a tool that allows kids to explore and learn by doing, by connecting and observing, span physical phenomena and real world events.

==Activity activities (hands on learning activities)==

See the [[Measure/Projects|projects]] page for detailed instructions on a few projects. Also see the [[Measure/Hardware|hardware]] page for other ideas.

Some threads for interesting learning experiments are below -

# Record animal sounds, for example, sounds of birds and observe their waveforms. Which of these are high frequency sounds, which are the low frequency ones? Adjust the frequency sliders accordingly.
# Whistle into the microphone and compare the loudness and frequency of whistles by observing the waveforms.
# Get two people to try to whistle the same note, and look into Beat Frequencies.
# Turn the sensitivity slider up to the maximum and observe ambient noise - in a quiet room, near a noisy road.
# Measure the voltage of an AA size pencil cell. What settings do you use? AC or DC?
# Measure resistance of water, other liquids
# Log temperature using a temperature sensor at one hour intervals. When in the day is it the hottest? The coldest?
# Some very interesting sensor ideas given by Arnans Roger, see - http://padthai.media.mit.edu:8080/cocoon/gogosite/documentation/makingSensors.xsp?lang=en

=Downloading the Activity=
Please visit the [[Measure/Download|download]] page to download the latest stable and unstable releases of the Activity.

=Kids guide to Measure=
=Teachers guide to Measure=
=Hacker's guide to Measure=

=Getting started=
==The software==
[[Image:Measure_1.png|thumb|200px|right|Signal in time domain]]
'''Input''':One can connect sensors/give input voltage through the pink Mic jack on the left side of the display screen. When nothing is connected there, the default signal is the sound signal from the built in Mic on the XO.
''Graph'': The green moving line on the screen indicates the signal


'''Grid and background''': The light grey lines that form a criss cross grid allow one to estimate the values of the signal at different instants of time. To get a value, multiply the Scale value for either the X Axis or the Y Axis (shown when one clicks on the "Show values" button in the Measure Toolbar) by the number of divisions of the grid in the X direction (horizontal) or Y direction (vertical).


'''Slider on the right''': The slider on the right controls the magnification (gain) of the waveform. Move it up if the waveform that you see is too small and move it down is the waveform is going out of the screen.
[[Image:Measure_3.png|thumb|200px|right|Signal in frequency domain]]


'''Measure Toolbar''': Use this to view and modify the signal.
*''AC/DC button'' -- This button selects whether you want to give a DC input or an AC input. Batteries, light sensors and temperature sensors have DC input. The microphone has an AC input.
*''Bias control button'' -- Some sensors would require this ON to work properly, most of the times you wouldn't need to touch this button. The built in mic requires this to be OFF.
*''Time/frequency button'' -- This button changes the X Axis from time-based to frequency-based, allowing one to view the signal representation or a real time representation of the signal. Selecting this option is most fun when one is whistling into the microphone. This wouldn't be of much use when connecting external sensors.
*''Slider'' -- Move it to the position that allows you to best view the waveform. This slider controls the frequency range.
*''Show details'' -- Press this button when you want to see statistical data about the signal. The scales are shown in this option - the X axis scale and the Y axis scale.


'''Log Toolbar''': Use this when you want to record data
''Snapshot/1 second/1 minute/1 hour'' -- Select the way you want to record data. Snapshot means taking a picture of the current waveform that you see on the screen. 1 second/1 minute/1 hour selects at what interval one can record data.
''Show saved data'' -- Shows you the saved waveform. Press it again to remove the display of the saved waveform.


{|
|-
|[[Image:Measure_4.png|thumb|300px|left|Displaying result of a logging session]]
|[[Image:Ver_14.png|thumb|300px|left|Showing the statistics about the signal]]
|}

== How to connect sensors (How to build a sensor-probe) ==
'''This section details outlines steps to build a low cost probe for connecting sensors to the XO for Measure'''

{|
|-
| valign='center'|
[[Image:Measure_tut_1_1.jpg|thumb|center|210px|It'd be good to have these tools - A soldering iron, some soldering wire, a wire cutter/wire stripper and some insulating tape]]
| valign='center'|
[[Image:Measure_tut_1_2.jpg|thumb|center|255px|Wire stripper]]
| valign='center'|
[[Image:Measure_tut_1_3.jpg|thumb|center|250px|Soldering wire]]
|-
| valign='center'|
[[Image:Measure_tut_1_5.jpg|thumb|center|263px|Some connecting wires]]
| valign='center'|
[[Image:Measure_tut_1_4.jpg|thumb|center|250px|3.5mm audio jack (stereo or mono, any would do)]]
| valign='center'|
[[Image:Measure_tut_1_6.jpg|thumb|center|246px|A USB cable, or even a USB connector would do]]
|-
| valign='center'|
[[Image:Measure_tut_1_9.jpg|thumb|center|260px|The audio jack/connector]]
| valign='center'|
[[Image:Measure_tut_1_10.jpg|thumb|center|250px|Cut two pieces of wire and strip them at the ends]]
| valign='center'|
[[Image:Measure_tut_1_11.jpg|thumb|center|180px|Solder the wires to the connector as shown. Do make sure to have an identification mark (eg. a knot) to differentiate between both the wires.Call the wire connected to the central terminal as "Vin" the wire connected to the outer terminal as "Gnd"]]
|-
| valign='center'|
[[Image:Measure_tut_1_13.jpg|thumb|center|250px|Take the USB cable/connector]]
| valign='center'|
[[Image:Measure_tut_1_14.jpg|thumb|center|250px|Cut it in the middle and strip the wires]]
| valign='center'|
[[Image:Measure_tut_1_15.jpg|thumb|center|180px|We only need the red and the black wires.The USB port provides us with a source of +5V supply. Let's call the red wire as "+ve" and the black as "Gnd" and make the black one and the "Gnd" defined in audio connector as one, by connecting them together.]]
|-
| valign='center'|
[[Image:Measure_tut_1_24.jpg|thumb|center|250px|The audio connector goes into the pink MIC input jack]]
| valign='center'|
[[Image:Measure_tut_1_27.jpg|thumb|center|250px|The USB connector goes into the USB port]]
|}

'''To summarize, do remember that we have identified three terminals
# The "Vin" terminal
# The "+ve" terminal
# The "Gnd" terminal (the Gnd of audio connector is connected to Gnd of USB connector"
'''


=Let's measure Temperature! ( Featured activity of the month )=

==Construction==
'''IMPORTANT - This section details how you can connect a temperature sensor to the sensor probe that you built. You should build the probe as outlined in [[Measure_/_Oscilloscope#How_to_connect_sensors_.28How_to_build_a_probe_to_connect_sensors_to_the_XO.29|how to connect sensors]] before moving forward. Most of all, you must remember that we need to know that we have three terminals (refer the section for details):
# The "Vin" terminal
# The "+ve" terminal
# The "Gnd" terminal (the Gnd of audio connector is connected to Gnd of USB connector
'''


{|
|-
| valign='center'|
[[Image:Measure_tut_1_7.jpg|thumb|center|222px|You would need a temperature sensor like this one LM35. A link is here- http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=LM35DZ-ND]]
| valign='center'|
[[Image:Measure_tut_1_8.jpg|thumb|center|155px|Taken from the data sheet of the temperature sensor, Vs is where we would supply the '''"+ve"''' (positive supply voltage), gnd is where would connect "-ve" (ground) and Vout is the sensor output which we will connect to "Vinput"]]
| valign='center'|
[[Image:Measure_tut_1_16.jpg|thumb|center|250px|So we connect the "Gnd" to the righten-most terminal of the sensor ]]
|-
| valign='center'|
[[Image:Measure_tut_1_17.jpg|thumb|center|250px|And connect the "+ve" to the left-most terminal of the sensor]]
| valign='center'|
[[Image:Measure_tut_1_19.jpg|thumb|center|250px|You might want to keep insulation tape handy at this time]]
| valign='center'|
[[Image:Measure_tut_1_21.jpg|thumb|center|250px|Apply the insulation tape over both the terminals]]
|-
| valign='center'|
[[Image:Measure_tut_1_22.jpg|thumb|center|208px|Now lets connect the "Vin" connector from the audio jack to the center terminal of the sensor, called as "Vout"]]
| valign='center'|
[[Image:Measure_tut_1_23.jpg|thumb|center|250px|Insert the audio connector to the Mic jack (pink)]]
| valign='center'|
[[Image:Measure_tut_1_24.jpg|thumb|center|270px|]]
|-
| valign='center'|
[[Image:Measure_tut_1_28.jpg|thumb|center|250px|Connect the USB connector to the USB port. Our temperature sensing probe is ready!]]
|}

==Operation and measurement==

'''Please download the Activity from the link title "For LM35" from the unstable branch by going to the [[Measure/Download|downloads]] page. This release is a pre-calibrated version for using with this temperature sensor.''''


[[Image:LM35.png|thumb|center|300px|This is what your temperature measurement would look like]]

[[Image:Img_3842.jpg|thumb|center|300px|Measuring temperature of water]]

= $2 USB I/O and sensor board =

[[Image:Sensor_Laptop_Wide.JPG |thumb|center|Low Cost USB Sensor board|300px]]

See Edward Baafi's low cost USB sensor board [[USB_Sensor|here]]

=Learning activities=

=Sensor Input into Turtle Art=

==Introduction==
[[Turtle_Art|Turtle Art]] is an abstraction. By allowing sensors to control various aspects of motion of the Turtle, one is enabling kids to connect with their physical world and bring that connection into the abstraction that Turtle Art represents

I've integrated sensor support into Turtle Art. This basically allows one to add a "Sensor Input" block into Turtle Art. One can thereby control any aspect of the Turtle's motion depending upon the value of the sensor. When no sensor is connected, the default input is taken from the Mic.

The code is in the git repository of Measure (look for the TurtleArt.activity folder)

==Screen shots==
[[Image:Measure_turtle1.png|thumb|400px|center|The turtle that moves in proportion to sensor input. Increasing the temperature made it move in larger squares]]
[[Image:TA_sensors_learning_workshop.png|thumb|400px|center|Program made during learning workshop at OLPC by Adrian and other participants (11th - 14th Feb) to log sensor values at an interval of five seconds]]
[[Image:Measure_turtle2.jpg|thumb|300px|center|For demonstration, heating the temperature sensor. This caused the Turtle to move larger distances]]

== Try it out! ==
If you wish to try out Turtle Art with sensors, please click [[Measure/Turtle|here]] to go the download and usage guidelines page.

==Work remaining==
* Input based on the frequency of signal. This would allow whistling at a higher frequency give a higher input
* Incorporating the various options (Bias/NoBias and AC/DC) into the UI of Turtle Art

==Acknowledgments==
Thanks to Brian Silvermann for helping me find my way in the existing Turtle Art code.

=Getting involved=

==Educators/Teachers==
We'd love help from educators. You can help by organizing learning activities around children wherever you are. Feel free to get in touch with us to discuss your ideas and co-ordinate efforts.

Document these learning activities that you undertake and help teachers and educators all around the world to replicate the same activities!

==Software developers==
Help is needed from volunteers from Python developers. Please visit [[Measure/Software|this]] page to find out details. If you have experience in writing optimized Python code, please leave a note on the discussion tab of this page and someone will get in touch with you.

==Hardware enthusiasts==
Do interesting hardware projects around the XO. Visit the [[Measure/Hardware|Measure hardware]] page to learn more. You might also want to see the [[Measure/Projects|projects]] page.


=Your experience with Measure ? =
Any thoughts that you want to share ? Any suggestions/criticism ?
Any interesting thing that you did or want to do with Measure Activity ?

Write/express/share in this space - [[Measure/Blog|the measure space]]

=A note about safety=
[[Image:Cautionary warning -- Caution.png|left|50px]]

'''SAFETY FIRST!'''

* Make measurements of AC line voltages with the proper equipment only -- for example, a multimeter designed for the purpose. The laptop is not a multimeter.

If you don't know what you are doing or are unsure, don't do it. Electricity can be dangerous.

=Future plans=
# Comparison of many graphs
# Sharing of the graphs
# Analog Input support into TamTam jam


For a version by version plans page see [[Measure/Plans|here]]



=Acknowledgments=
* Walter Bender - (my adviser) providing invaluable guidance, encouragement and support at all stages of development. I have had immense learning during the development of the Activity and I hope to allow kids to experience learning while using the Activity as much as I experienced while making the Activity.
* Thanks to Mitch Bradley and John Watlington for their help and suggestions during the development of the Activity.
* Thanks for Bernardo Innocenti and Michael Stone for their valuable inputs towards code design.
* Community - Thank you for your feedback and support. I believe our efforts would go a long way in enabling kids in developing countries have a better learning experience!


=Proposed re-organization of this page=

==General goals==
* small overall size of page
* links to other pages with a picture accompanying what the link is about
* links depend on the user and what he/she has come to look for on the page

==Possible links==
* Educators
* Getting started (perhaps on the main measure page itself)
* Activity activities
* Developers

=Contact=
Contact Arjun Sarwal through -

Email : arjun AT laptop dot org

IRC : arjs on #olpc #sugar









'''Give a child a hammer and the world becomes his nails...'''

Revision as of 17:59, 8 April 2008

Page used for re-organizing Measure page w/o disturbing the main page till the re-organization is done


Kids and Parents

There are plenty of opportunities for kids and parents alike to get involved in the OLPC project. You can:


Teachers and Educational Organizations

Are you a teacher or high school/college student? You can contribute by doing testing, development, mentoring, and more.

Content

You don't have to code to contribute! There are plenty of ways that artists, writers, photographers, etc. can help out.


Translators

This is a global project; we ♥ people who can help translate wiki content, software, and content bundles.

Developers and Testers

Getting started is pretty easy for testers and developers. There is a strong developer community, as well as a developer support infrastructure.


Hardware

There are lots of hardware opportunities, from alternative power brainstorming to peripheral development to XO repair.

Local opportunities

Help create changes in the community you live in - as well as ones you'd like to go to.


Virtual opportunities

There are plenty of ways to get involved online.


For an older overview of getting involved, see the more detailed page Getting involved in OLPC, or Participate (Old Page).

Retrieved from "http://wiki.laptop.org/mediawiki/index.php?title=Measure/New_temp&oldid=124310"