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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 lang=EN-CA style='mso-fareast-language:EN-US'>2 things I forgot to mention:<o:p></o:p></span></p><ul style='margin-top:0cm' type=disc><li class=MsoListParagraph style='margin-left:0cm;mso-list:l0 level1 lfo1'><span lang=EN-CA style='mso-fareast-language:EN-US'>The paper scrolling speed will be derived from one of the PIC’s TIMER interrupts<br>who’s timeout will be varied from the reading of a pot (ADC) value. (1feet/min to 13feet/min adjusted).<o:p></o:p></span></li></ul><p class=MsoListParagraph><span lang=EN-CA style='mso-fareast-language:EN-US'>Constant and accurate.<o:p></o:p></span></p><ul style='margin-top:0cm' type=disc><li class=MsoListParagraph style='margin-left:0cm;mso-list:l0 level1 lfo1'><span lang=EN-CA style='mso-fareast-language:EN-US'>The actual vertical size of each holes of the brass reading bar is about the size of the tinny paper studs left<o:p></o:p></span></li></ul><p class=MsoNormal style='text-indent:35.4pt'><span lang=EN-CA style='mso-fareast-language:EN-US'>Between each repetitive holes. In a pneumatic situation the passage of these small paper studs are not seen<o:p></o:p></span></p><p class=MsoNormal style='text-indent:35.4pt'><span lang=EN-CA style='mso-fareast-language:EN-US'>From the brass bar reader and interpreted as a continuous note line.<o:p></o:p></span></p><p class=MsoNormal style='text-indent:35.4pt'><span lang=EN-CA style='mso-fareast-language:EN-US'>Because of that I don’t know if playing with IR LEDS angle will actually change something..<o:p></o:p></span></p><ul style='margin-top:0cm' type=disc><li class=MsoListParagraph style='margin-left:0cm;mso-list:l0 level1 lfo1'><span lang=EN-CA style='mso-fareast-language:EN-US'>Interesting to see that there are no half tone pair of notes next to each others in the paper rolls I have<o:p></o:p></span></li></ul><p class=MsoListParagraph><span lang=EN-CA style='mso-fareast-language:EN-US'>Again to keep paper sturdiness.. Always separated by at least one whole tone note paper space !<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>One other thing for me to check for:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>Because Infrared light seems to be easily blocked by moving paper<br>compared to visible light I’m using 940nm wavelength IR LEDS/Photo-transistors.<br>But to do that I’ll need some kind of PCB bar to hold an array of IR LEDS<br>over the brass bar row of reading holes </span><span lang=EN-CA style='font-family:Wingdings;mso-fareast-language:EN-US'>à</span><span lang=EN-CA style='mso-fareast-language:EN-US'> hidding an horizontal part of the moving paper roll .. Not very cute..<br>I was thinking of something else that could work..<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>Heat is Infrared so.. Using a heating element wire over all the brass bar holes<br>could be seen as a LEDS array but smaller in width (no PCB).<br>This wire just heated a little could be glued in a plexiglass transparent Bar<br>placed over the brass reading bar.??<br>Or use some kind of diffused incandescent light all over the scrolling paper<br>that has infrared specs close to 940nm.. ?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>But I’m about sure heating wire spectral wavelength would be far from my needed 940nm..<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>Hmmm…<o:p></o:p></span></p><div style='mso-element:para-border-div;border:none;border-bottom:solid windowtext 1.0pt;padding:0cm 0cm 1.0pt 0cm'><p class=MsoNormal style='border:none;padding:0cm'><span lang=EN-CA style='mso-fareast-language:EN-US'><o:p> </o:p></span></p></div><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><p class=MsoNormal><span lang=EN-CA>> On Nov 10, 2022, at 5:56 PM, Jean-Pierre Desrochers <</span><a href="mailto:jpdesroc@oricom.ca"><span lang=EN-CA>jpdesroc@oricom.ca</span></a><span lang=EN-CA>> wrote:<br>> <br>> Hi all,<br>> <br>> My Player piano reader project is going fine so far..<br></span>> 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).<br>> 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..<br>> The second line shows what the reading Photo transistor ‘sees’<br>> and the third line shows an ideal reading stored in the micro.<br>> So far there are 2 ways I found to get close of the ideal reading :<br>> #1 Place a capacitor in parallel with each Photo transistors to get rid of the ‘pulsating holes’ on a continuous note<br>> #2 Use software with separate counters to ‘skip’ the incoming small pulses just enough not to miss any ‘real’ short notes.<br>> My challenge here is that the paper roll speed will be a variable one<br>> which could be varied from 1feet/min up to 13feet/min.<br>> 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 !<br><br>_______________________________________________<br>Synth-diy mailing list<br><a href="mailto:Synth-diy@synth-diy.org">Synth-diy@synth-diy.org</a><br><a href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a><br>Selling or trading? 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