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</o:shapelayout></xml><![endif]--></head><body lang=FR-CA link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><span style='mso-fareast-language:EN-US'>Hi all,<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>My Player piano reader project is going fine so far..<br>Some little robotics stuff (stepper motors, sensors, etc..) going on now..<br>I’m now in the process of reading the small holes scrolling<br>with the music paper rolls ‘sandwiched’ between Infrared leds and 88 x Photo transistors (see the image below).<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>The actual music data appears on the paper as parallel lines of small successive holes<br>shown in blue below. Because of the need of paper sturdyness for long duration notes the original paper punches<br>made small successive holes in the same note line instead of a steady cut in paper<br>that could eventualy be damaged over time..<br>That is shown by the blues dots below (successive holes).<br>Now I need to read these constant note ‘ignoring’ all the occuring small holes<br>during these long duration notes..<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>The second line shows what the reading Photo transistor ‘sees’<br>and the third line shows an ideal reading stored in the micro.<br><b>So far there are 2 ways I found to get close of the ideal reading :<o:p></o:p></b></span></p><p class=MsoNormal><b><span style='mso-fareast-language:EN-US'>#1 Place a capacitor in parallel with each Photo transistors to get rid of the ‘pulsating holes’ on a continuous note<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='mso-fareast-language:EN-US'>#2 Use software with separate counters to ‘skip’ the incoming small pulses just enough not to miss any ‘real’ short notes.</span></b><span style='mso-fareast-language:EN-US'><br>My challenge here is that the paper roll speed will be a variable one<br>which could be varied from <b>1feet/min</b> up to <b>13feet/min</b>.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>That’s a 1 to 13 ratio !!<br>So method #1 using caps in parallel with the photo-transistors (fixed RC time) will not be feasable (I think).<br>Is there another way you could think of to get rid of these small pulses<br>when necessary ? <br>Thanks !<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><img width=1125 height=416 style='width:11.7187in;height:4.3333in' id="Image_x0020_2" src="cid:image002.jpg@01D8F546.F8500820"></span><span style='mso-fareast-language:EN-US'><o:p></o:p></span></p></div></body></html>