<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;"><br><br><font face="arial" size="2">--- On </font><b style="font-family: arial; font-size: 10pt; ">Fri, 9/21/12, Kevin Mark <i><kevin.mark@verizon.net></i></b><font face="arial" size="2"> wrote:</font><br><blockquote style="border-left-width: 2px; border-left-style: solid; border-left-color: rgb(16, 16, 255); margin-left: 5px; padding-left: 5px; "><br><font face="arial" size="2">From: Kevin Mark <kevin.mark@verizon.net></font><br><font face="arial" size="2">Subject: Re: [support-gang] What Sensors and Where To Buy?</font><br><font face="arial" size="2">To: "support-gang@laptop.org" <support-gang@laptop.org>, "IAEP SugarLabs" <iaep@lists.sugarlabs.org>, "OLPC SoCal" <olpc-socal@laptop.org>, "Community Support Volunteers -- who help respond to help AT laptop.org" <support-gang@lists.laptop.org></font><br><font face="arial"
size="2">Date: Friday, September 21, 2012, 2:55 AM</font><br><br><div id="yiv766011679" style="font-family: arial; font-size: 10pt; "><table cellspacing="0" cellpadding="0" border="0"><tbody><tr><td valign="top" style="font:inherit;"><br><br><font face="arial" size="2">--- On </font><b style="font-family:arial;font-size:10pt;">Thu, 9/20/12, Caryl Bigenho <i><cbigenho@hotmail.com></i></b><font face="arial" size="2"> wrote:</font><br><blockquote style="border-left-width:2px;border-left-style:solid;border-left-color:rgb(16, 16, 255);margin-left:5px;padding-left:5px;"><br><font face="arial" size="2">From: Caryl Bigenho <cbigenho@hotmail.com></font><br><font face="arial" size="2">Subject: [support-gang] What Sensors and Where To Buy?</font><br><font face="arial" size="2">To: "support-gang@laptop.org" <support-gang@laptop.org>, "IAEP SugarLabs" <iaep@lists.sugarlabs.org>, "OLPC SoCal" <olpc-socal@laptop.org></font><br><font
face="arial" size="2">Date: Thursday, September 20, 2012, 8:37 PM</font><br><br><div id="yiv766011679">
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<div dir="ltr"><p style="font-family:arial;font-size:12px;"><font face="Verdana">Hi…</font></p>
<p style="font-family:arial;font-size:12px;min-height:14px;"><font face="Verdana"><br></font></p>
<p style="font-family:arial;font-size:12px;"><font face="Verdana">OK, here I am again with another "dumb" question… well, maybe not so dumb after all as I'll bet there are others out there who could also use this information. On the OLPC wiki there are several very nicely illustrated instructions about how to make sensors to use with the XO… temperature, humidity, light, etc. But, they don't include a materials list or reference to sources where the parts can be purchased.</font></p><p style="font-family:arial;font-size:12px;"><font face="Verdana"><br></font></p><p style="font-family:arial;font-size:12px;"><a rel="nofollow" target="_blank" href="http://wiki.laptop.org/go/Making_XO_sensors">http://wiki.laptop.org/go/Making_XO_sensors</a></p>
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<p style="font-family:arial;font-size:12px;"><font face="Verdana">Radio Shack? Edmond Scientific? Parallax.com? or where? Curious people, myself included want to know. Can someone help here?</font></p>
<p style="font-family:arial;font-size:12px;min-height:14px;"><font face="Verdana"><br></font></p>
<p style="font-family:arial;font-size:12px;"><font face="Verdana">Thanks!</font></p>
<p style="font-family:arial;font-size:12px;"><font face="Verdana">Caryl (GrannieB)</font></p>
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<p style="font-family:arial;font-size:12px;"><font face="Verdana">P.S. Here's an example of the type of info needed. This site sells a number of light sensors but they call them things like Photoresistor, Photo Transistor, Light to Frequency Converter. These are all little ones that appear similar to the one in the instructions on the wiki. How do you tell which kind you need?</font></p><p style="font-family:arial;font-size:12px;"><font face="Verdana"><br></font></p></div></div></div></div></blockquote><font face="arial" style="font-family:Verdana;"><span style="font-size:12px;">I'm not someone schooled in Electronics, just an </span></font><font face="Verdana" style="font-size:12px;">autodidact. If you are talking about a 'light sensor', this is usually a device that when exposed to visible white light will change its electrical re</font><font face="arial"><span style="font-size:12px;">sistance. If you are familiar with the
concept of volts, current, and resistance, the basic components of Ohms Law, this device would be part of a circuit and act as a gauge for the amount of lightness or darkness in a room. So the device would increase its resistance which is measured in Ohms when more light hits the active surface. if you buy this[0] at Radio Shack, it will contain various types of these cells. The main difference is their resistance range. Some might vary the resistance from 0 to 1,000 Ohms, some might vary from 0 to 10,000 Ohms. Or other response ranges. </span></font><br><span style="font-size:12px;font-family:arial;">The names can vary. I first knew them as a Cadmium Sulfate Cell, they can also Light </span><span style="font-size:12px;font-family:arial;">Dependent</span><span style="font-size:12px;font-family:arial;"> resistors. Or Photoresisitors.</span><br><span style="font-size:12px;font-family:arial;">As for the
light to frequency converter, that is a different device.</span><div><font face="arial"><span style="font-size:12px;">For the sake of experimentation and convience, the radioshack package might be an OK $4 investment. If you know someone who likes electronics, they might have these parts to space. Even better if you can visit a 'hackerspace' where they can help with a few parts and explanation.</span></font></div><div><font face="arial"><span style="font-size:12px;"><br></span></font></div><div><font face="arial"><span style="font-size:12px;">I</span></font><span style="font-size:12px;font-family:arial;"> think the main use is to connect the light sensor directly to the audio-in port of the XO, which means a few wires, an audio jack and the light sensor. The 'Measure' Activity should provide a basic idea of how the sensor reacts to varying amounts of light.</span></div><div><font face="arial"><span style="
font-size:12px;"><br></span></font><div dir="ltr"><div dir="ltr"><p><font face="arial"><span style="font-size:12px;">[0] https://www.radioshack.com/product/index.jsp?productId=2062590</span></font></p></div></div></div></td></tr></tbody></table></div><br></blockquote><font face="arial" size="2"><br></font><span style="font-family: arial; font-size: small; ">This is a minor update because I was reading a post[1] on sparkfun. This kit shows a kit with single examples of various types of sensors. This kit is too expensive but you can buy the </span><span style="font-family: arial; font-size: small; ">individual</span><span style="font-family: arial; font-size: small; "> parts </span><span style="font-family: arial; font-size: small; ">separately at their site or elsewhere</span><span style="font-family: arial; font-size: small; ">.</span><br><div class="plainMail"><font face="arial" size="2">[1]
https://www.sparkfun.com/products/11283</font></div><div class="plainMail"><font face="arial" size="2">-k</font></div></td></tr></table>