<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">In that case, I would go with a bunch of the more modern time-of-flight (TOF) sensors, like the ST VL6180X:<div class=""><a href="https://www.st.com/en/imaging-and-photonics-solutions/vl6180x.html" class="">https://www.st.com/en/imaging-and-photonics-solutions/vl6180x.html</a></div><div class=""><br class=""></div><div class="">These would be independent of ambient lighting. This one is I2C but there are others with SPI. And a bit pricey, but I know for sure I’ve seen some that are < €1, but can’t find them now.</div><div class=""><br class=""></div><div class="">Ben</div><div class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 20 Mar 2021, at 14:02, Ingo Debus <<a href="mailto:igg.debus@gmail.com" class="">igg.debus@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class=""><br class=""><blockquote type="cite" class="">Am 19.03.2021 um 23:06 schrieb Didrik Madheden <<a href="mailto:nitro2k01@gmail.com" class="">nitro2k01@gmail.com</a>>:<br class=""><br class="">So that gives me a different idea for a working principle based on<br class="">light: reflection. No hole=light reflects back. Only one side of the<br class="">paper has electronics. This could be done with either a visible LED<br class="">(for an additional visualizer effect) or an IR LED (for<br class="">authentic-looking operation).<br class=""></blockquote><br class="">That was my idea too. Would the good old CNY70 do the trick?<br class=""><a href="https://www.vishay.com/ppg?83751" class="">https://www.vishay.com/ppg?83751</a><br class=""><br class="">But then, 90 of these will eat quite a lot of power for the infrared-LEDs…<br class=""><br class="">Ingo<br class="">_______________________________________________<br class="">Synth-diy mailing list<br class="">Synth-diy@synth-diy.org<br class="">http://synth-diy.org/mailman/listinfo/synth-diy<br class="">Selling or trading? Use marketplace@synth-diy.org<br class=""><br class=""></div></div></blockquote></div><br class=""></div></body></html>