<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Wingdings;
panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
{mso-style-priority:99;
mso-style-link:"Texte brut Car";
margin:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;
mso-ligatures:standardcontextual;
mso-fareast-language:EN-US;}
span.EmailStyle20
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.TextebrutCar
{mso-style-name:"Texte brut Car";
mso-style-priority:99;
mso-style-link:"Texte brut";
font-family:"Calibri",sans-serif;
mso-ligatures:standardcontextual;
mso-fareast-language:EN-US;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:70.85pt 70.85pt 70.85pt 70.85pt;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:61174009;
mso-list-type:hybrid;
mso-list-template-ids:1043732758 1012971438 202113027 202113029 202113025 202113027 202113029 202113025 202113027 202113029;}
@list l0:level1
{mso-level-start-at:0;
mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:Wingdings;
mso-fareast-font-family:Calibri;
mso-bidi-font-family:"Times New Roman";}
@list l0:level2
{mso-level-number-format:bullet;
mso-level-text:o;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:"Courier New";}
@list l0:level3
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:Wingdings;}
@list l0:level4
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:Symbol;}
@list l0:level5
{mso-level-number-format:bullet;
mso-level-text:o;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:"Courier New";}
@list l0:level6
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:Wingdings;}
@list l0:level7
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:Symbol;}
@list l0:level8
{mso-level-number-format:bullet;
mso-level-text:o;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:"Courier New";}
@list l0:level9
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:Wingdings;}
ol
{margin-bottom:0cm;}
ul
{margin-bottom:0cm;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=FR-CA link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoPlainText><span lang=EN-CA>Hi again Gerry,</span><b><i><span lang=EN-CA><o:p></o:p></span></i></b></p><p class=MsoPlainText><b><i><span lang=EN-CA><o:p> </o:p></span></i></b></p><p class=MsoPlainText><b><i><span lang=EN-CA>> Hi JP<o:p></o:p></span></i></b></p><p class=MsoPlainText><b><i><span lang=EN-CA>> Another attempt at attaching the image. This time as a gif.<o:p></o:p></span></i></b></p><p class=MsoPlainText><b><i><span lang=EN-CA>> Hope you can open it.<o:p></o:p></span></i></b></p><p class=MsoPlainText><span lang=EN-CA>It worked !<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoPlainText><b><i><span lang=EN-CA>> I think if you use two sensors, you have the increased accuracy that comes from two signals when balanced.<o:p></o:p></span></i></b></p><p class=MsoPlainText><b><i><span lang=EN-CA>> If you use one sensor, you would be comparing the signal to a reference voltage but the sensor signal could vary with temperature or supply variations. <o:p></o:p></span></i></b></p><p class=MsoPlainText><b><i><span lang=EN-CA>> Using two sensors, each would be equally affected by temperature & voltage variations and this would reduce the system error.<o:p></o:p></span></i></b></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>The idea of using only one sensor was without any opamp at all.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>Only the sensor’s open collector output to a micro-controller..<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>Here again are my thoughts on that:<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'>But what about using only one sensor at the right paper side??</span><span lang=EN-CA><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>If the output is low (IR beam passes , Paper too far left) move the paper right</span><span lang=EN-CA><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>If the output is high (IR beam hidden, Paper too far right) move the paper left</span><span lang=EN-CA><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>This way the centering will continually look for the output ‘transition’ position<br>to ‘consider’ the paper is at the right position..</span><span lang=EN-CA><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>But ONLY at the transition position.<br>But doing so the centering will ALWAYS be working.. but that could be OK<br>for a very precise centering.. </span><o:p></o:p></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'>**********************************************************<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'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=FR>De :</span></b><span lang=FR> Gerry Murray <synthimuse@gmail.com> <br><b>Envoyé :</b> 9 avril 2023 19:16<br><b>À :</b> Jean-Pierre Desrochers <jpdesroc@oricom.ca><br><b>Cc :</b> 'synth-diy mailing list' <synth-diy@synth-diy.org><br><b>Objet :</b> Re: [sdiy] My Player piano roll project... refining my design<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Hi JP<o:p></o:p></p></div><div><p class=MsoNormal>Another attempt at attaching the image. This time as a gif.<o:p></o:p></p></div><div><p class=MsoNormal>Hope you can open it.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I think if you use two sensors, you have the increased accuracy that comes from two signals when balanced.<o:p></o:p></p></div><div><p class=MsoNormal>If you use one sensor, you would be comparing the signal to a reference voltage but the sensor signal could vary with temperature or supply variations. <o:p></o:p></p></div><div><p class=MsoNormal>Using two sensors, each would be equally affected by temperature & voltage variations and this would reduce the system error.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>That's just the way it seems to me.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Happy to hear others views.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Best regards<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Gerry<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 10/04/2023 00:03, Jean-Pierre Desrochers wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal><span style='mso-fareast-language:EN-US'>Clever idea too !</span><o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'> </span><o:p></o:p></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>But what about using only one sensor at the right paper side??</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>If the output is low (IR beam passes , Paper too far left) move the paper right</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>If the output is high (IR beam hidden, Paper too far right) move the paper left</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>This way the centering will continually look for the output ‘transition’ position<br>to ‘consider’ the paper is at the right position..</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>But ONLY at the transition position.<br>But doing so the centering will ALWAYS be working.. but that could be OK<br>for a very precise centering.. Hmmm..</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'> </span><o:p></o:p></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'> </span><o:p></o:p></p><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=FR>De :</span></b><span lang=FR> The SynthiMuse <a href="mailto:synthimuse@gmail.com"><synthimuse@gmail.com></a> <br><b>Envoyé :</b> 9 avril 2023 17:27<br><b>À :</b> Jean-Pierre Desrochers <a href="mailto:jpdesroc@oricom.ca"><jpdesroc@oricom.ca></a><br><b>Cc :</b> synth-diy mailing list <a href="mailto:synth-diy@synth-diy.org"><synth-diy@synth-diy.org></a><br><b>Objet :</b> Re: [sdiy] My Player piano roll project... refining my design</span><o:p></o:p></p></div></div><p class=MsoNormal> <o:p></o:p></p><div><p class=MsoNormal>Hi JP<o:p></o:p></p><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal>I should have been clearer earlier on so I've attached a scribbled image of my idea.<o:p></o:p></p></div><div><p class=MsoNormal>There's no need to invert one of the signals. You just need to get nice linear values from 2 sensors and put them into a differential amplifier. This will give you a DC value that will tell you the position error and you can use it to drive the correction mechanism.<o:p></o:p></p></div><div><p class=MsoNormal>Obviously, if the signal from the two sensors are equal, then the paper is perfectly centred.<o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal>I hope this helps.<o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal>Best wishes <o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal>Gerry<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 Sun, 9 Apr 2023, 17:24 Jean-Pierre Desrochers, <<a href="mailto:jpdesroc@oricom.ca" target="_blank">jpdesroc@oricom.ca</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt'><div><div><p> <o:p></o:p></p><p><span lang=EN-CA>Very good idea.</span><o:p></o:p></p><p><span lang=EN-CA>If I understand correctly their would be 2 sensors close to each other</span><o:p></o:p></p><p><span lang=EN-CA>but set a little apart from each ones. (But on one of the two paper sides only)</span><o:p></o:p></p><p><span lang=EN-CA>If so there would be some kind of detected ‘notch’ or ‘peak’</span><o:p></o:p></p><p><span lang=EN-CA>to tell the paper is correctly placed right ?</span><o:p></o:p></p><p><span lang=EN-CA>But when this peak or notch disappears how can I know which direction to move the paper</span><o:p></o:p></p><p><span lang=EN-CA>and correct its position ?</span><o:p></o:p></p><p><span lang=EN-CA>I would need the same tandem on the other paper edge.. ?</span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA>******************************************************************************</span><o:p></o:p></p><p>De : Synth-diy <mailto:<a href="mailto:synth-diy-bounces@synth-diy.org" target="_blank">synth-diy-bounces@synth-diy.org</a>> De la part de Gerry Murray via Synth-diy<o:p></o:p></p><p>Envoyé : 9 avril 2023 11:20<o:p></o:p></p><p>À : mailto:<a href="mailto:synth-diy@synth-diy.org" target="_blank">synth-diy@synth-diy.org</a><o:p></o:p></p><p><span lang=EN-CA>Objet : Re: [sdiy] My Player piano roll project... refining my design</span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA>Hi JP</span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA>I would recommend two of these sensors operated in linear mode, with a small difference in their physical position and invert the signal from one of them.</span><o:p></o:p></p><p><span lang=EN-CA>From these two signals you would get a 'detent' differential signal that would tell you the lateral error and allow you to adjust the horizontal position of the paper more accurately.</span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA>Best wishes</span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA>Gerry</span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA>On 09/04/2023 16:09, Jean-Pierre Desrochers wrote:</span><o:p></o:p></p><p><span lang=EN-CA>Hi all again,</span><o:p></o:p></p><p><span lang=EN-CA>I’m still trying to refine my design and working on</span><o:p></o:p></p><p><span lang=EN-CA>the paper centering process circuit.</span><o:p></o:p></p><p><span lang=EN-CA>So far I’m using the tracker bar edge’s holes to detect</span><o:p></o:p></p><p><span lang=EN-CA>left/right paper movements while playing the rolls.</span><o:p></o:p></p><p><span lang=EN-CA>Those who are at the paper’s edge sides. </span><o:p></o:p></p><p><span lang=EN-CA>The system works pretty well </span><o:p></o:p></p><p><span lang=EN-CA>but still some rolls lacks of centering correction.</span><o:p></o:p></p><p><span lang=EN-CA>SO I want to do some tests using Photointerrupters - Slot Type – with open collector Outputs.</span><o:p></o:p></p><p><span lang=EN-CA>Like those types:</span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA>I’m trying to select the best accurate one to detect paper edges</span><o:p></o:p></p><p><span lang=EN-CA>not the overall paper cutting the IR beam..</span><o:p></o:p></p><p><span lang=EN-CA>Any idea of the best specifications to pick one ?</span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p>De : Synth-diy mailto:<a href="mailto:synth-diy-bounces@synth-diy.org" target="_blank">synth-diy-bounces@synth-diy.org</a> De la part de Jean-Pierre Desrochers<o:p></o:p></p><p>Envoyé : 23 février 2023 17:31<o:p></o:p></p><p>À : mailto:<a href="mailto:Synth-diy@synth-diy.org" target="_blank">Synth-diy@synth-diy.org</a><o:p></o:p></p><p><span lang=EN-CA>Objet : [sdiy] My Player piano roll project... a small video demo for you..</span><o:p></o:p></p><p><span lang=EN-CA>Importance : Faible</span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA>I’m not done yet with this project but this is promissing..</span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA><a href="https://www.youtube.com/watch?v=K7xXYqCB0AY" target="_blank">https://www.youtube.com/watch?v=K7xXYqCB0AY</a></span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA>I let the piano roll play its song while filming.. around 4:00 duration.</span><o:p></o:p></p><p><span lang=EN-CA>Enjoy !</span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p><p><span lang=EN-CA>_______________________________________________</span><o:p></o:p></p><p><span lang=EN-CA>Synth-diy mailing list</span><o:p></o:p></p><p><span lang=EN-CA>mailto:<a href="mailto:Synth-diy@synth-diy.org" target="_blank">Synth-diy@synth-diy.org</a></span><o:p></o:p></p><p><span lang=EN-CA><a href="http://synth-diy.org/mailman/listinfo/synth-diy" target="_blank">http://synth-diy.org/mailman/listinfo/synth-diy</a></span><o:p></o:p></p><p><span lang=EN-CA>Selling or trading? Use mailto:<a href="mailto:marketplace@synth-diy.org" target="_blank">marketplace@synth-diy.org</a></span><o:p></o:p></p><p><span lang=EN-CA> </span><o:p></o:p></p></div></div><p class=MsoNormal>_______________________________________________<br>Synth-diy mailing list<br><a href="mailto:Synth-diy@synth-diy.org" target="_blank">Synth-diy@synth-diy.org</a><br><a href="http://synth-diy.org/mailman/listinfo/synth-diy" target="_blank">http://synth-diy.org/mailman/listinfo/synth-diy</a><br>Selling or trading? Use <a href="mailto:marketplace@synth-diy.org" target="_blank">marketplace@synth-diy.org</a><o:p></o:p></p></blockquote></div></div></blockquote><p><o:p> </o:p></p></div></div></body></html>