<html><head><style> body {height: 100%; color:#000000; font-size:12pt; font-family:times new roman,new york,times,serif;}</style></head><body><div>I know... you're building the first Digital Harmonica!</div><div><br></div><div>Will it have MIDI ?</div><div><br></div><div>Harry</div><div><br></div><div>----- Original Message -----<br>From: Jean-Pierre Desrochers <jpdesroc@oricom.ca><br>To: synth-diy@synth-diy.org<br>Sent: Fri, 19 Mar 2021 11:09:35 -0400 (EDT)<br>Subject: [sdiy] Very cheap SPI pressure sensors.. anybody ??<br></div><div><br></div><style><!--<br><div><br></div>@font-face<br> {font-family:Calibri;<br> panose-1:2 15 5 2 2 2 4 3 2 4;}<br>@font-face<br> {font-family:Tahoma;<br> panose-1:2 11 6 4 3 5 4 4 2 4;}<br><div><br></div>p.MsoNormal, li.MsoNormal, div.MsoNormal<br> {margin:0cm;<br> margin-bottom:.0001pt;<br> font-size:11.0pt;<br> font-family:"Calibri","sans-serif";<br> mso-fareast-language:EN-US;}<br>a:link, span.MsoHyperlink<br> {mso-style-priority:99;<br> color:blue;<br> text-decoration:underline;}<br>a:visited, span.MsoHyperlinkFollowed<br> {mso-style-priority:99;<br> color:purple;<br> text-decoration:underline;}<br>p.MsoPlainText, li.MsoPlainText, div.MsoPlainText<br> {mso-style-priority:99;<br> mso-style-link:"Texte brut Car";<br> margin:0cm;<br> margin-bottom:.0001pt;<br> font-size:11.0pt;<br> font-family:"Calibri","sans-serif";<br> mso-fareast-language:EN-US;}<br>p.MsoAcetate, li.MsoAcetate, div.MsoAcetate<br> {mso-style-priority:99;<br> mso-style-link:"Texte de bulles Car";<br> margin:0cm;<br> margin-bottom:.0001pt;<br> font-size:8.0pt;<br> font-family:"Tahoma","sans-serif";<br> mso-fareast-language:EN-US;}<br>span.TextebrutCar<br> {mso-style-name:"Texte brut Car";<br> mso-style-priority:99;<br> mso-style-link:"Texte brut";<br> font-family:"Calibri","sans-serif";}<br>span.TextedebullesCar<br> {mso-style-name:"Texte de bulles Car";<br> mso-style-priority:99;<br> mso-style-link:"Texte de bulles";<br> font-family:"Tahoma","sans-serif";}<br>.MsoChpDefault<br> {mso-style-type:export-only;<br> font-family:"Calibri","sans-serif";<br> mso-fareast-language:EN-US;}<br>@page WordSection1<br> {size:612.0pt 792.0pt;<br> margin:70.85pt 70.85pt 70.85pt 70.85pt;}<br>div.WordSection1<br> {page:WordSection1;}<br>--></style><div class="WordSection1"><p class="MsoPlainText"><span lang="EN-CA">I'm looking for very cheap SPI pressure sensors (around $1.00 a piece or less)</span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">For a future project. The pressure value doesn't matter but the size and cost do.</span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">I will need around 90 of these sensors.</span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;"> </span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">For example I found this:</span></p><p class="MsoNormal"><span lang="EN-CA">BMP180 GY-68 GY68 3.3V 5V BMP-180 Temperature Pressure Sensor Module Barometric IIC I2C Interface Sensor Module Replace BMP085 $0.90CAD</span></p><p class="MsoNormal"><a href="https://www.aliexpress.com/item/32832330585.html?src=google&albch=shopping&acnt=708-803-3821&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=UneMJZVf&&albagn=888888&isSmbAutoCall=false&needSmbHouyi=false&albcp=7386552844&albag=80241711349&trgt=743612850714&crea=en32832330585&netw=u&device=c&albpg=743612850714&albpd=en32832330585&gclid=CjwKCAjw9MuCBhBUEiwAbDZ-7mU2hTS0J2DLxvsPsj8F40L-zV8vtApw9ds_ks1c2Qjg7dLiKgsy3RoCq-EQAvD_BwE&gclsrc=aw.ds" target="_blank" data-mce-href="https://www.aliexpress.com/item/32832330585.html?src=google&albch=shopping&acnt=708-803-3821&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=UneMJZVf&&albagn=888888&isSmbAutoCall=false&needSmbHouyi=false&albcp=7386552844&albag=80241711349&trgt=743612850714&crea=en32832330585&netw=u&device=c&albpg=743612850714&albpd=en32832330585&gclid=CjwKCAjw9MuCBhBUEiwAbDZ-7mU2hTS0J2DLxvsPsj8F40L-zV8vtApw9ds_ks1c2Qjg7dLiKgsy3RoCq-EQAvD_BwE&gclsrc=aw.ds"><span lang="EN-CA">https://www.aliexpress.com/item/32832330585.html?src=google&albch=shopping&acnt=708-803-3821&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=UneMJZVf&&albagn=888888&isSmbAutoCall=false&needSmbHouyi=false&albcp=7386552844&albag=80241711349&trgt=743612850714&crea=en32832330585&netw=u&device=c&albpg=743612850714&albpd=en32832330585&gclid=CjwKCAjw9MuCBhBUEiwAbDZ-7mU2hTS0J2DLxvsPsj8F40L-zV8vtApw9ds_ks1c2Qjg7dLiKgsy3RoCq-EQAvD_BwE&gclsrc=aw.ds</span></a><span lang="EN-CA"></span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">But because I need 90 devices and the BMP180 is I2C and has only one address value<br>I would need somekind of multiplexer to address 90 devices (one at the time obviously).</span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">So.. SPI devices would fit better here.</span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;"> </span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">One other possibility would be to use this type:</span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">MPS20N0040D MPS20N0040D-D Sphygmomanometer Dip Air Pressure Sensor 0-40kPa DIP-6 For Arduino Raspb $0.74CAD</span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;"><a href="https://www.aliexpress.com/item/4000354356373.html?src=google&albch=shopping&acnt=708-803-3821&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=UneMJZVf&&albagn=888888&isSmbAutoCall=false&needSmbHouyi=false&albcp=9604672960&albag=100679328364&trgt=296904913880&crea=en4000354356373&netw=u&device=c&albpg=296904913880&albpd=en4000354356373&gclid=CjwKCAjw9MuCBhBUEiwAbDZ-7kff0q--0F6YUo73aVqE_HAtqkRyIslFbEMRTWz7QICR2szctlC7zxoCrMUQAvD_BwE&gclsrc=aw.ds" target="_blank" data-mce-href="https://www.aliexpress.com/item/4000354356373.html?src=google&albch=shopping&acnt=708-803-3821&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=UneMJZVf&&albagn=888888&isSmbAutoCall=false&needSmbHouyi=false&albcp=9604672960&albag=100679328364&trgt=296904913880&crea=en4000354356373&netw=u&device=c&albpg=296904913880&albpd=en4000354356373&gclid=CjwKCAjw9MuCBhBUEiwAbDZ-7kff0q--0F6YUo73aVqE_HAtqkRyIslFbEMRTWz7QICR2szctlC7zxoCrMUQAvD_BwE&gclsrc=aw.ds">https://www.aliexpress.com/item/4000354356373.html?src=google&albch=shopping&acnt=708-803-3821&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=UneMJZVf&&albagn=888888&isSmbAutoCall=false&needSmbHouyi=false&albcp=9604672960&albag=100679328364&trgt=296904913880&crea=en4000354356373&netw=u&device=c&albpg=296904913880&albpd=en4000354356373&gclid=CjwKCAjw9MuCBhBUEiwAbDZ-7kff0q--0F6YUo73aVqE_HAtqkRyIslFbEMRTWz7QICR2szctlC7zxoCrMUQAvD_BwE&gclsrc=aw.ds</a></span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;"> </span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">But I’ll need some analog IC to manage the output..</span></p><p class="MsoPlainText"><b><span data-mce-style="text-decoration: underline;" style="text-decoration: underline;"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">Again the part’s pressure specs value do not matter.. I will manage a way to use it.</span></span></b></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">but the size and cost do.</span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;"> </span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">So far the best would be a SPI equivalent of the BMP180 IC..</span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">Let me know if someone googled something I did not spot !</span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;"> </span></p><p class="MsoPlainText"><span lang="EN-CA" style="color:black" data-mce-style="color: black;">JP</span></p></div><div><br></div></body></html>