Color sensing (as well as detecting empty spaces) settled on IR-based sensors commonly used in line-following robots. You can watch the clock in action in the video embedded below just under the ...

How about building your own visual thermometer for cheap? That’s what [Thomas Fischl] decided to do, using an infrared thermal sensor array (MLX90640) connected through a PIC16LF1455 to a host ...

However, the required sources, detectors, and optical components are costly and difficult to integrate into portable devices.

An IR sensor is located near the TV and wired to the receiver, which can be many feet away in the equipment rack. The receiver has an amplifier and an "IR blaster" that showers IR signals to all ...