What kind of sensor should I use to measure hot and cold drinks just beyond a sheet of glass?
I want to design a robot/computer that will be placed under a piece of glass, and give out readings to my controller as to the temperature of whats on the glass. I was going to use a red and blue LED, displaying/mixing the colors to glow as hot and cold items are moved around on the glass (coffee table). What kind of sensor should I use? Can I use a typical IR sensor? or something more elaborate?