Ooops, I re-read the OP and my suggestion is clearly not viable here. On 2 September 2015 at 03:06, Justin Richards wrote: > When I was experimenting the infra-red LEDs I observed that the mark-spac= e > ratio of the received pulse stream varied as the distance varied. > > It seemed to be useful (easily detectable) from about 5cm to 30 cm but > perhaps it could be optimised for different distances. > > I attributed the effect to the saturation of the receiving LED. > > I filed the observation away along with the possibility of using it in my > window frames to report not just if the window is open, but also by how > much. > > Justin > > On 1 September 2015 at 11:39, Neil wrote: > >> Anyone know of a non-contact distance sensor that can measure up to say >> 1 inch? I built a machine for maker faire (in less than 2 weeks) that >> lets people draw on a touch screen an that will get printed with >> frosting on a cookie. But if the cookie is not flat (rarely are they >> really flat), there are issue with the frosting not sticking properly in >> some corners or sharp curves. I'm thinking if I can map the surface of >> the cookie quickly before printing each one, I can have the Z-axis track >> the cookie's "terrain". This is a fun project so low-cost is important. >> >> Cheers, >> -Neil. >> >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .