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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Since you are collapsing all of the breakout boards, what are your plans for the processor?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>As I recall, the reason for having to invert the signal was due to a limitation on the external<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>interrupt pin of the processor. Newer Atmel chips have pin change interrupts on all pins<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>and can handle either edge. So, if you go with an ATTiny 84 or similar, you don’t need the transistor.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>---> Paul<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> TriEmbed [mailto:triembed-bounces@triembed.org] <b>On Behalf Of </b>Charles McClelland<br><b>Sent:</b> Friday, March 21, 2014 3:47 PM<br><b>To:</b> Glen Smith<br><b>Cc:</b> TriEmbed Discussion<br><b>Subject:</b> Re: [TriEmbed] Giving this Surface Mount Thing a Try - Transistor Help Needed<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Glen, <o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I am using EAGLE - it allows you to set the names so I guess I have to take responsibility - Resister Base (RB) - I am learning so if there is a better naming convention I should be using, I would be open to it.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Thanks,<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Chip<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Mar 21, 2014, at 1:29 PM, Glen Smith <<a href="mailto:mrglenasmith@gmail.com">mrglenasmith@gmail.com</a>> wrote:<o:p></o:p></p></div><p class=MsoNormal><br><br><o:p></o:p></p><div><div><div><div><div><p class=MsoNormal style='margin-bottom:12.0pt'>Charles,<o:p></o:p></p></div><p class=MsoNormal style='margin-bottom:12.0pt'>As Bill said, there are single gate IC's to do what you want, a quick glance indicates the cheapest (in one'sie two'sie quantities) is $0.33. But there are 2222 transistors available in SOT-23 packages: Jameco has them here: <br><a href="http://www.jameco.com/webapp/wcs/stores/servlet/StoreCatalogDrillDownView?langId=-1&storeId=10001&catalogId=10001&freeText=2222%20sot-23&search_type=jamecoall">http://www.jameco.com/webapp/wcs/stores/servlet/StoreCatalogDrillDownView?langId=-1&storeId=10001&catalogId=10001&freeText=2222%20sot-23&search_type=jamecoall</a> <br>qty 10 available at $0.09 each. Or, to keep the comparison, DigiKey has them here: <br><a href="http://www.digikey.com/product-search/en?pv7=2&FV=142c0042&k=MMBT2222A&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25">http://www.digikey.com/product-search/en?pv7=2&FV=142c0042&k=MMBT2222A&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25</a> <br>(for one'sie two'sie quantities) at $0.18 each.<o:p></o:p></p></div><p class=MsoNormal style='margin-bottom:12.0pt'>It has been far too long since I did transistor circuit design to tell you whether what you have will do the inversion you want, but you can hook it up on a breadboard with your discrete's and see how it works.<o:p></o:p></p></div><p class=MsoNormal style='margin-bottom:12.0pt'>Since I'm sending this note anyway, is there a reason why you chose RA, RB RC designations? It took me a few minutes looking at your circuit to figure out that it was a designator rather than a ResistorCapacitor (RC) network. Maybe it is just what I'm used to working with. Which layout tool are you using? KiCAD or Eagle? If one of them forces me to use RA, RB, RC - I think I will use the other.<o:p></o:p></p></div><p class=MsoNormal>Glen<o:p></o:p></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p><div><p class=MsoNormal>On Fri, Mar 21, 2014 at 12:46 PM, Bill Farrow <<a href="mailto:bill@arrowsreach.com" target="_blank">bill@arrowsreach.com</a>> wrote:<o:p></o:p></p><div><div><p class=MsoNormal>Charles,<o:p></o:p></p></div><div><p class=MsoNormal>There are single logic gate ICs in surface mount which should do what you want. Here's my quick digikey search.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal><a href="http://www.digikey.com/product-search/en?pv247=24&pv64=1&pv667=1&pv69=3&FV=fff40027%2Cfff8019d&k=single+gate&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25" target="_blank">http://www.digikey.com/product-search/en?pv247=24&pv64=1&pv667=1&pv69=3&FV=fff40027%2Cfff8019d&k=single+gate&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25</a><span class=hoenzb><span style='color:#888888'><o:p></o:p></span></span></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><span style='color:#888888'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='color:#888888'>Bill<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='color:#888888'><o:p> </o:p></span></p></div></div><p class=MsoNormal style='margin-bottom:12.0pt'><br>_______________________________________________<br>Triangle, NC Embedded Computing mailing list<br><a href="mailto:TriEmbed@triembed.org">TriEmbed@triembed.org</a><br><a href="http://mail.triembed.org/mailman/listinfo/triembed_triembed.org" target="_blank">http://mail.triembed.org/mailman/listinfo/triembed_triembed.org</a><br>TriEmbed web site: <a href="http://triembed.org/" target="_blank">http://TriEmbed.org</a><o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p></div></div></body></html>