Whereas the motion sensor is handy for those in the van to check the ghost’s location, the infrared light sensor lets those already in the house know where the ghost might be.

Why Your Smartphone Needs an Infrared Sensor You could use a heat sensor to check your house for leaks, for instance. But mostly, it's a lot of fun.

If you are using infrared (IR) hardware in an IoT, embedded, or mobile hardware project and are currently experiencing difficulties debugging IR communications, using one of the circuits shown ...